Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. The Caribbean forester U. S. DEPARTMENT OF AGRICULTURE FOREST SERVICE TROPICAL FOREST EXPERIMENT STATION RIO PIEDRAS, PUERTO RICO -OLUME 17, NOS. 1 AND 2 JANUARY - JUNE, 1956 Caribbean Forester El “Caribbean Forester’, revista que el Servicio Forestal del Departamento de Agri- cultura de los Estados Unidos comenz6 a pu- blicarse en julio de 1938 se distribuye semes- tralmente sin costo alguno y esta dedicada a encauzar la mejor ordenacién de los recursos forestales de la regién del Caribe. Su propo- sito es estrechar las relaciones que existen entre los cientificos interesados en la Ciencia Forestal y ciencias afines encaradndoles con los problemas confrontados, las politicas fo- restales vigentes y el trabajo que se viene haciendo para lograr ese objetivo técnico Se solicita aportaciones de no mas de 20 paginas mecanografiadas. Deben ser someti- das en el lenguaje vernaculo del autor, con el titulo o posicién que este ocupa. Es impres- cindible incluir un resumen conciso del estu- dio efectuado. Los articulos deben ser dirigi- dos al Lider, Centro de Investigaciones Fo- restales Tropicales, Rio Piedras, Puerto Rico. Las opiniones expresadas por los autores de los articulos que aparecen en esta revista no coinciden necesariamente con las del Ser- vicio Forestal. Se permite la reproduccién de los articulos siempre que se indique su proce- dencia. @ The “Caribbean Forester”, published since July 1938 by the Forest Service, U. S. Depart- ment of Agriculture, is a free semiannual journal devoted to the encouragement of im- proved management of the forest resources of the Caribbean region by keeping students of forestry and allied sciences in touch with the specific problems faced, the policies in effect, and the work being done toward this end throughout the region. Contributions of not more than 20 type- written pages in length are solicited. They should be submitted in the author’s native tongue, and should include the author’s title or position and a short summary. Papers should be sent to the Leader, Tropical Forest Research Center, Rio Piedras, Puerto Rico. Opinions expressed in this journal are not necessarily those of the Forest Service. Any article published may be reproduced provided that reference is made to the original source. Le “Caribbean Forester’, qui a été publié depuis Juliet 1938 par le Service Forestier du Département de l’Agriculture:des Etats-Unis, est une revue semestriele gratuite, dediée a encourager laménagement rationnel des fo- réts de la region caraibe. Son but est d’entre- tenir des relations scientifiques entre ceux qui sinteréssent. aux Sciences Forestiéres, ses problémés et ses méthodes les plus récentes, ainsi qu’aux travaux effectués pour réaliser cet objectif d’amelioration technique. On accept voluntiers des contribution ne dépassant pas 20 pages dactilographiées. Elles doivent étre écrites dans la langue ma- ternelle de l’auteur qui voudra bien préciser son titre ou sa position professionnelle et en les accompagnant d’un résumé de l’étude. Les articles doivent étre addressés au Leader, ‘Tropical Forest Research Center, Rio Pie- dras, Puerto Rico. La revue laisse aux auteurs la responsibi- lité de leurs articles. La reproduction est permise si l’on présice l’origine. “The printing of this publication has been approved by the Director of the Bureau of the Budget (August 26, 1953) VoL. 17 Nos. 1 AND 2 JANUARY - JUNE 1956 iune Ganiowean Forester @Gomren is S) Uad CheiKe: DEXLEeMLNE AMM Are POGb =. 2 ee 1 Tropical Forest Research Center, Puerto Rico Additions to the flora of St. Barthelemy ___ = Lay Pere C. Le Gallo and Joseph Monachino, New York Forest preservation in the Windward Islands ____________ 25 He Fraser, st: Lucia; BWI. The forestry phase of the United States Technical Assistance Program in Chile ___ i ee eel TIS Jay H. Hardee, Chile Procedimientos para pequenos viveros forestales en Chile__ 37 Jay H. Hardee, Chile JANUARY - JUNE 1956 Sixteenth Annual Report Tropical Forest Research Center Puerto Rico The year 1955 was marked by a substan- tial expansion of the activities of the Research Center. A new project of watershed manage- ment was set up, the Caribbean National Forest was taken over for research purposes, a program of cooperative forest management with the local governments and private land- owners in both Puerto Rico and the Virgin Islands was undertaken, and a {full-time pro- gram of training for foreign forestry students was inaugurated. Forest management research, on the other hand, suffered from a vacancy in the Project Leader position for 6 months of the year. Be- cause of this circumstance new experiments were limited almost entirely to four in the Virgin Islands, described in more detail later in this report. These experiments, carried out cooperatively with the Virgin Islands Corpo- ration and the Virgin Islands Experiment Station, involved six trips to the area during the year. The reexamination schedule for the 356 tests in progress in Puerto Rico and the Virgin Islands at the beginning of the year was revised to reduce this job to the bare minimum which would assure adequate in- formation as to the results. Of these tests 84 were terminated, and 19, including 6 in the Virgin Islands, were started during the year. Much of the time of the available Forest Management personnel has been dedicated to compilation of information for two large pub- lication, a bulletin on planting, and a des- criptive book on Trees of Puerto Rico for which the senior author is Dr. Elbert L. Little, dr. of the Division of Forest Management Re- search of the office of the Chief in Washing- ton. At the end of the year the checking of the tree descriptions and the translation of the first review draft into Spanish by the Forest Management staff was nearly complet- ed. The data for the planting bulletin have all been brought together. The administration of the Caribbean Na- tional Forest, and area of some 33,000 acres, was assigned the Center for research purposes in July. By the end of the year a plan was prepared for the future use of the Luquillo Division of this forest. Included are long- range experiments in silviculture and a large- scale pilot-demonstration forest management project which will apply best known practices of silviculture, timber harvesting, and utiliza- tion. A watershed management research project was begun in the second half of the year with the assignment of three professional men. The project leader, available only part time because of primary responsibilities for the foreign training program, has begun work on a problem analysis as a step preliminary to long-range research in this field. The other two men in this Division are specialits on a one-year assignment from the Vicksburg In- filtration Project of the U. S. Army Engineers. This Project is concerned with the prediction of soil moisture and trafficability. The re- search has consisted of taking daily readings on rainfall, soil moisture and temperature, and soil strength at 7 sites and similar data cn a monthly basis for an additional 23 sites. The cooperative forestry program taken over in July provides a new opportunity for the Center to reach the practitioner with the results of research. In Puerto Rico this co- operation has been with both the Common- wealth government and with ferest land- owners. With the Commonwealth it has in- cluded assistance in the orientation of the joint Federal-State program of propagation and distribution of forest tree nursery stock to farmers and related technical advice on nursery practices. In addition, a joint field study was made by the forestry staffs of the two governments of problems related to the administration and management of six of the 2, Commonwealth forests. Plans have also been completed with the Department of Public Works for the establishment of 4 kilometers of timber tree plantings along key roads. With farmers the cooperative forestry program has concentrated on the location of key farms for the establishment of demon- stration woodlots of 14 acre or more. ‘Twelve farms of this type have been found and plans made for the farmer to complete the plant- ings during the next wet season. This program is an attempt to spearhead a new technique of giving much more preliminary attention to farm plantings, technical advice at the time of planting, and subsequent follow up. If re- sults are as successful as anticipated it is hoped that the Division of Forests and the Extension Service will adopt this practice in the future. In the Virgin Islands a full time forester was appointed by the Center during the year, financed by the Virgin Islands Corporation. His work is primarily the encouragement of forest inmprovement on private lands in those islands by underplanting native forests with mahogany stands, and by harvesting and util- izing rmature trees. Some 19,000 mahogany trees were planted cooperatively by farmers as a result of this program during the year. The 130-acre Thomas Estate Demonstration Forest, an area of excellent young mahogany stands, was given an improvement cutting. A small circular sawmill was set up and readi- ed for cutting local timber for farm use, in- dustrial development, and research purposes. Material assistance was offered in the research work in progress in the Virgin Islands, in- cluding seed collections, the setting up of plots in the field, planting, and subsequent measure- ments. Recognition of the increasing importance of forestry training at the Center came with the assignment during the year of a forester nearly full time to this activity, financed by the International Cooperation Administration. A 3-month training course was held in the spring of the year, with 26 foreign students . CARIBBEAN FORESTER present. The Food and Agriculture Organiza- tion of the United Nations assisted in this course in various ways, including the sending of two instructors. A second, 8-week session was held in the autumn for four students from the British Caribbean islands. Forest utilization research was concerned chiefly with the study of machining properties, air-seasoning characteristics, and certain re- lated physical properties of 60 native timbers. The remodeling of the wood testing laborato- ry buildings was completed and the required machines and equipment were installed. Near- ly all of the lumber required had been cut and was drying or under test at the end of the year. The Project Leader made a trip to the Forest Products Laboratory at Madi- son, Wisconsin for consultation in regard to this research, and also to attend the Annual Program Planning Conference. Mr. E. M. Davis of the Laboratory spent 10 days in Puerto Rico to assist with techniques for the machining tests. The major international activity of the Center. in addition to the training, was parti- cipation in the Fifth Session of the Latin American Forestry Commission of FAO, at Caracas, Venezuela. The Center Leader at- tended this conference as an advisor to the U. S. Delegation and served on the subcom- mission concerned with the proposed Latin American Forest Research and Training In- stitute at Merida, Venezuela. The Center has received more cooperation in its activities than ever before. This is parti- cularly true in the field of training, where virtually all agricultural agencies, both Fede- ral and Commonwealth, were of assistance. In addition to other types of cooperation al- ready mentioned, the Center is indebted to the Division of Forests, Fisheries and Wild- life for continued assistance in the conduct of field experiments on lands under their ad- ministration. This cooperation has been res- ponsible for many of the findings reported here. JANUARY - JUNE 1956 FOREST MANAGEMENT RESEARCH The more important results of forest management research in progress during 1955 are described briefly here. Some of these will soon be presented more completely in publish- ed form. Others are only partial and re- present progress reports on long-range studies. The results of research are presented for each of the major forest problem areas under study. These problem areas, described in detail in last year’s report, cover nearly one- third of Puerto Rico. They are areas where forest is the only or the most promising crop. Humid Tuffaceous Loams One of the largest potential forest areas of Puerto Rico is characterized by shallow loam soils derived from tuffaceous rock. About 170,000 acres are included. Slopes are steep, generally exceeding 60 percent. Elevations range from 300 to 2,500 feet. Rainfall ranges from 70 to 120 inches annually. The chief problem in this area is reforesta- tion. Regeneration research is in progress with a number of native and exotic tree species. Almost nothing has been known about the potential productivity of the scat- tered native forests of this region. Woodlot Management Most of the humid tuffaceous loam area is in small private holdings. Thus it is imper- ative that an effort be made to show forestry profitable for the farmer. With this in mind a 10-acre mixed secondary forest in the St. Just Experimental Area was placed under in- tensive management in 1942. Areas were subjected to annual improvement cuttings favoring the trees of best form and species. In one area the objective has been to produce sawtimber and in another to produce fence posts. Quarter-acre sample plot records indi- cate stand developments and the yields to be expected. In the stand where sawtimber is the objec- tive the basal area was 455 square feet and the volume, §78 cubic feet per acre (in trees 9 0 of 2 inches d.b.h. or more) after cutting in 1954. The annual increment per acre during the two previous years was 218 cubic feet The stand is still too young to yield sawtimber out produced 134 fence posts annually the jast 2 years. These, on the stump, were worth $5.36 or manufectured, $16.08. Seventy- nine percent of the treas remaining are of sawtimber species and form. In the stand where fence posts are the ob- jective the basal area was 40 square feet and the volume, 717 cubic feet per acre after cut- ting in 1954. The annual increment per acre during the two previous years was 165 cubic feet. Cuttings during the past 2 years produc- ed 184 fence posts annually. These, on the stump, were worth $7.36 or manufactured, $22.08. All of tke trees remaining in this stand are of species and form suited for posts. The yields in the fence post stand is prob- ably indicative of what can be expected under management. In the sawtimber stand the value of the yield will rise continuously as tree size increases. Deep Lateritic Clays Some 190,000 acres of steep slopes in the interior of Puerto Rico constitute a second important potential forest area. Elevations range from 500 to 4,000 feet with rainfall from 80 to 200 inches annually. The chief problem in this area is reforesta- tion, but there are also extensive areas of de- graded secondary forests and abandoned coffee plantations which need silvicultural improve- ment to increase their productivity. Research is in progress in reforestation with a large number of species on different sites. The bet- terment of existing forests both by partial cuttings and by underplanting is also being investigated. Hurricane Damage Hurricane Connie on August 6, 1955 pass- ed about 135 miles north of an 18-year-old plantation of broadleaf mahogany (Swietenia macrophylla King) in the Luquillo Forest. Winds reported to range in gusts up to 60 4 miles per hour caused severe damage in about 50 acres of plantations. This was the first opportunity in 24 years to study the effects of a hurricane upon forest plantations in Puerto Rico. The plantation in this area is located on the slopes of a deep North-South valley. The elevation is about 1,200 feet and the rainfall averages about 140 inches annually. The soil is a deep red clay with many boulder out- crops. The plantation was established in de- forested areas following shifting cultivation. Within the plantation are many areas of na- tural forest, and some native trees are in places mixed with the mahogany. In the first few years of the plantation it was noted that the trees were not windfirm and tended to blow over easily. However, subsequently the remaining trees formed buttresses, and wind- throw ceased. By 1955 the average dia- meter of dominant and codominant trees had reached 10 inches. The damage occurred only on west slopes, yet the trees were thrown northward. More trees were affected in the valleys than on the ridges. Mahogany was far more susceptible to windthrow than any associated aative species, even including yagrumo hembra (Ce- cropia peltata L.). im the pure plantation as many as 80 percent of the mahoganies were windthrown over areas as large as an acre. Most of the trees affected were uprooted rather than broken off. There was little ap- parent relationship between tree size or ex- posure and damages. In some areas a few fine large specimens, with diameters up to 14 inches survived undamaged with other down all around them. Other mahoganies, protect- ed beneath a native overstory, were blown down although the overstory remained un- damaged. The only evidence of any pattern was a tendency for the completely devastated areas to be arranged in strips of about 100 feet in width, perpendicular to the wind direc- tion. Between these strips there was relative- ly little damage. A most striking characteristic of the up- : rooted trees was the limited spread of their CARIBBEAN FORESTER root system. Examination showed the aver- age diameter of the root system to be only 1 foot for every inch of stem diameter at breast height. This limitation, possibly caus- ed by excessive soil moisture, appears to be a basic weakness of the species in this environ- ment. The hurricane winds did not reach maho- gany plantations on other sites in Puerto Rico. It is hoped that they will not prove to be as susceptible as in the Luquillo Mountains. Planting of mahogany, heretofore the most promising species for moist deep clays, has been at least temporarily suspended. The effect of the hurricane upon the native forest, even in the immediate vicinity of the damage mahogany, was negligible. No saw- timber-sized trees of native species were da- maged. Breakage in the native forests was almost entirely confined to the soft-wooded rapid growers which spring up in openings but were already disappearing with the re- development of a mixed forest beneath them. Natural Regeneration The first extensive natural regeneration of broadleaf mahogany (Swietenia macrophylla King) was discovered in March 1955 under a 27-year-old pure plantation in the Luquillo Mountains. ‘This plantation is located at an elevation of about 800 feet and receives a rain- fall of about 90 inches annually. The plantation was undamaged until its 25th year, at which time it was lightly thin- ned to 105 square feet of basal area. The average diameter of the remaining dominant and codominant trees was 11 inches at that time. . In 1953, the first year subsequent to the thinning, a crop of fruits was noticed on the trees for the first time. The first seedling counts in 1955 were made in seven circular plots of 20 feet in diameter. Counts ranged from 2,200 to 14,300 seedlings per acre, many of which were obviously in their second year. Subsequent counts in December showed vir- tually no mortality. There now appears to be little doubt that this species, once estab- lished, should be easy to regenerate. JANUARY - JUNE 1956 Artificial Regeneration A major obstacle to reforestation by pri- vate landowners is the cost of weeding re- cently planted trees. An ingenious technique used under some conditions outside of Puerto Rico is the interplanting of food crops between the rows of trees. The crop yields harvested before the trees dominate pay the costs of cultivation and plantation establishment. The rapid growth of eucalyptus in this region and the light shade produced by plantations of this species in Puerto Rico suggested inter- cultivation as a substitute for weeding. A test was started in 1953 in the Toro Negro forest at 2,800 feei elevation with a rainfall of 120 inches annually. The test area covered an acre. Trees of Eucalyptus robusta Smith were planted at an 8 x 12-foot spacing, and interplanted with bananas. At the end of 18 months both the trees and the bananas are very thrifty. The trees average about 10 feet tajl with a max- imum of 15 feet. This is about double the growth nearby without intercultivation. The bananas have not yet fruited but a good crop is anticipated. Observations will continue to determine if and when the bananas should be removed. Because they are shade tolerant, it may prove possible to produce both crops throughout the rotation. Piantation Growth One of the more promising exotic trees for planting in this region is the blue mahoe (Hi- biscus elatus Sw.), a native of Jamaica and Cuba. Plantings in humid forests were at- tacked at an early age by the West Indian peach scale and considered beyond redemption. However, the insect attacks. apparently in- iluenced by weather conditions, have subsided te a point where a small planting in the Toro Negro Forest suggests more extensive trials. The mahoe at Toro Negro is growing at an elevation of about 2,600 feet with a rain- fall of about 110 inches annually. It was planted in a protected cove on land formerly cultivated and abandoned. Trees not damag- 3) ed by insect attack are of excellent form and, afier 7 years average 5.5 inches d.b.h. and 65 feet in height. The largest trees are 9 inches in diameter and 75 feet tall. This growth is comparable to eucalyptus, yet the wood of this species is of quality suitable for furniture. Granitic Loams The granitic loam soils of the central and eastern mountains are one of the highest ero- sion hazards in the island. Some 59,000 acres of these soils, on slepes in excess of 60 percent, are considered suitable only for forest. The major forest problem in this region is reforestation, although a substantial area of secondary forest needs improvement. Re- search on both techniques is in progress. Plantation Growth Cne of tne earliest forest plantations in Puerto Rico was established in the Luquillo Forest at an elevation of 1,200 feet in 1931. The annual rainfall is about 140 inches. The species is broadleaf mahogany (Swietenia macrophylla King). Now after 24 years the dominant and codominant trees range from 12 to 21 inches, d.b.h. Forty trees in this plantation have been under study for the past 3 years to determine current diameter growth. The annual growth of 18 dominant and codominant trees has been 0.84 inch, as rapid as for any other species on this site, including eucalyptus. Even the trees in the intermediate crown class grow 0.59 inch. These trees are of excellent form and well buttressed. They have not yet ex- perienced a hurricane but nevertheless thi is the most promising timber species for this soil type. Mexican cypress (Cuppressus lusitanica Mill) previously reported as of rapid growth on deep clay soils is also developing well on granitic loam in the southern portion of the Luquillo Forest. The site is located at about 2,000 feet elevation and receives about 140 inches of rainfall annually. A test planting was established in 1948 and by 1955 average 4 to 6 inches d.b.h. and 20 to 25 feet in height. A few of the trees have tipped over as is apparently characteris- tic of this species at elevations as low as this, but the stand in general shows no sign of this problem. Further trials of this species on this soil, particularly in the Central Mountains, are warranted. The Laterite Soils Near the western end of the Central Cor- dillera is an area of about 22,000 acres of laterite soil which, because of low fertility, is unsuited to other than forest crops. The soil ranges from shallow to deep, elevations from 800 to 2,500 feet, and rainfall from 50 to 100 inches annually. The major problems are reforestation of bare lands and the betterment of unproduc- tive secondary woodlands. Research is in progress in reforestation and subsequent plan- tation management. Artificial Regeneration The absence of a high quality native species generally adapted to the more humid deeper soils of this type at higher elevations led to introductions in 1953, previously re- ported, of a variety of pines. The species test- ed included Pinus canariensis C. Sm., P. hale- pensis Bieb., P. patula Sch. & Cham., P. taeda L., P. occidenialis Swartz, P. radiata D. Don, P. caribaea More, P. pinaster Aiton, P, pinea L., and P. densiflora Sieb. & Zucc. The plantings were made in the Maricao Forest at an elevation of about 2,000 feet, and with about 100 inches of rainfall annual- ly. During the first year the trees became chlorotic in appearance and ceased growth. Ammonium superphosphate was applied as a soil amendment but produced no visible re- action in the seedlings. Finally, in 1955, my- corrhiza from stands of P. taeda L. and P. echinata Mill. in the southern United States were added to the soil around the roots of the trees. No conclusive results are yet available. CARIBBEAN FORESTER Humid Limestone The humid limestone region covers about 150,000 acres between the Cordillera and the northern coastal plain. It is chiefly of steep hills with soil which is shallow and of low productivity for cultivated crops. Elevations range from sea level to about 1,000 feet and rainfali from 60 to 80 inches annually. The chief forest problem in this region is the improvement of existing forests. Research is in progress on stand betterment and parti- cularly the introduction of superior tree species into the stands. Woodlot Management A typical forested area in this region was selected in 1950 in the Cambalache Experi- mental Forest for experimental management as a farm woodlot. It has been subjected to annual improvement cuttings. There are no sawtimber species present so the objective of management has been the production of fence posts. The first measurements made in this stand showed that woodlot improvement purely by partial cuttings would be slow and would yield little early reward. The average tree diameter was 2 inches, with the largest to 5 inches. Tree form was poor and vines covered much of the stand. Even after 5 years almost no fence posts have been produced. However, the stand itself has been improved materially. The basal area in good post species increased from 22 to 31 square feet per acre, and now con- stitutes 79 percent of the stand. Seventy- five percent of the saplings are of these bet- ter species. This stand has been gradually improved silviculturally, but the practice has so little to recommend it from the standpoint of im- mediate economic returns that the only pro- mising approach appears to be unterplanting with superior species. Underplanting Broadleaf mahogany (Swietenia macro- phylla King) is still the most promising tree JANUARY - JUNE 1956 for introduction into the natural forests of this region. An underplanting was made in the Cambalache Experimental Forest in 1945. Elevation is about 100 feet and rainfall 60 inches annualy. After 10 years the dominant and codominant trees had attained an average d.b.h. of 4 inches and an average height of 30 feet. The best growth in this plantation has taken place within 50 feet of the bottoms of the slopes. The trees required frequent opening in the first 5 years to assure them of light from above. Blue mahoe (Hibiscus elatus Sw.) retfer- red to elsewhere in this report, is also well adapted to the lower slopes in the Cambalache Forest. However, it is less tolerant than mahogany and requires heavy release from overhead shade at an early age. At age 10 years the dominant and codominant trees average 5 inches in d.b.h. and 50 feet in height. Form is excellent, and this is the only loca- tion in the island where the trees have been entirely free from attack by the West Indian peach scale. Tidal Swamps About 16,000 acres of tidal swamps along the coast of the island cannot be drained economically. This area is covered with young mangrove which because of its acces- sibility and rapidity of growth is potentially a highly productive forest. The most important problem in this forest is the determination of effective techniques for promptly regenerating the forest with the more desirable species. A second problem is the need for thinning practices. Research on both of these problems has been in progress for several years. Natura! Regeneration A thinning made in a 22-year-old pure stand of white mangrove (Laguncularia race- mosa (L). Gaertn.) produced an almost im- mediate increase in increment but did nct bring on natural regeneration. Extensive areas of white mangrove within the Aguirre Forest are mature for poles, the i highest use of this species. Whereas experi- ence had shown that the regeneration of such a forest would take place after clear cutting, such regeneration is normally so dense that the development of the new stand is believed to suffer. Accordingly, when in 1952 a thin- ning was made experimentally in two 14-acre plots the objective was partially to determine whether a more satisfactory new stand would develop beneath it. The diameter of the dominant and codo- minant trees ranged from 5 to 12 inches. The average basal area in trees of 2 inches or more, d.b.h. was 134 square feet per acre, and the standing volume was 2,960 cubic feet per acre. Mean annual increment had been 128 cubic feet per acre per year. The thinning reduced the basal area to 70 square feet per acre. In- crement for the first 3 years following thin- ning was 125 cubic feet per acre per year, as compared with 29 cubic feet in the unthinnedc plots. The acceleration of increment resulting from this thinning is pronounced but of sec- ondary importance, in that most of the stems are already mature. The thinning was un- satisfactory as a preparatory cutting for re- generation. ‘The stand, even-aged without young trees beneath it at the time of thinning, is now more open but it is stiil without a new crop on the ground. This is true even in one plot where only 63 square feet of basal area per acre were left. Beneath the larger canopy openings there are ferns but except for a few scattered saplings of red mangrove (Rhizophora mangle L.) and black mangrove (Avicennia nitida Jacq.) no new trees have appeared. The most important conclusion from this study is in regard to the intolerance of white mangrove. In upland forests a satisfactory stand of reproduction of at least some specie: would develop under the conditions created by the thinning. White mangrove apparently will not. Heavier thinning would apparently be unwise because of the constant danger of windthrow on this site. A windstorm in 1949. 8 oven before the thinning, eliminated 120 trees per acre, including many dominants. Ap- parently regeneration can best be brought about by clearcutting. A practical technique for obtaining prompt regeneration of clearcut mangrove areas was developed in the Aguirre Forest as a result of a study which began in 1951. Since that time a strip 1 chain wide and perpen- dicular to the prevailing wind direction has been cut each second year. Each new strip is adjacent to the last strip cut, and on the windward side. This has produced complete stands of white mangrove saplings in 24 months. After 4 years the trees are 2 to 4 inches d.b.h. and to 25 feet in height. Past observation in the natural regenera- tion of white mangrove following clearcutting led to the conclusion that it is mostly cop- pice. This has been a source of some concern since sprouts, although they grow rapid et first, are generally of poor form and necessi- tate early thinnings. A comparative study of 80 sprouts and seddlings in the strip cutover in 1951 was undertaken in 1954.. At this time it was still possible to distinguish the sprouts from the seedlings. The sprouts tended to be larger (1.5 inches d.b.h. average vs. 1.0 inck for seedlings) but the latter were straighter, and would generally be easily identified by characteristic swellings at the base. A re- measurement at the end of the first year, while not entirely conclusive, showed results so striking as to appear worthy of reporting. The average diameter growth o! 55 sprouts was 0.27 inch, whereas that for 19 comparable seedlings will hold their own in the canopy and possibly continue to outstrip the sprouts in development. If this finding pzoves3 gen- erally applicable it will eliminate the major objection to clearcutting of white mangrove and will greatly simplify management. The Virgin Islands The American Virgin Islands, with a forest land area of approximately 45,000 acres, have undertaken a forestry program in recent years, : CARIBBEAN FORESTER sponsored by the Virgin Islands Corporation. The chief problems are the improvement of extensive brushlands and the reforestation of arroyos and stream courses. Forest research has been in progress in the Virgin Islands since 1953, in cooperation with the Virgin Islands Corporation and the Virgin Islands Agricultural Experiment Sta- tion of the U. S. Department of Agriculture. Studies have concentrated chiefly upon under- planting of mahogany (Swietenia mahagoni Jacq and S. macrophylla King). Seed Studies Poor viability of the seed of both species of mahogany has during the past 3 years greatly limited the progress of tree propaga- tion, and investigations of broadcasting and direct sowings in the field. Such losses in past years were attributed to lack of refrigera- tion during storage, in accordance with ex- perience in Puerto Rico. However, germina- tion tests made in 1955 showed initial viabili- ty to be extremely erratic and generally low. The highest germination percent obtained for any sample of broadleaf mahogany (S. macro- phylla) was 62 percent. For West Indian mahogany it was 19 percent. These figures are lower than those obtained from Puerto Rico. Attention is now concentrated upon im- proved seed collection and handling tech- niques. Collection of seed, heretofore done chiefly by school children, in part for publici- ty purposes, will in the future all be done by trained crews. Other possible past sources of viability loss, failure to clean the seed promptly, and high-temperature drying under direct sunlight, will be eliminated. Refrige- rated storage has already been introduced. Teak (Tectona grandis L.) is being tested for reforestation of arroyos in St. Croix. Ger- mination of the seed proved so slow that production of nursery stock has been costly. As a result two presowing treatments in use in the Far East were tested. JANUARY - JUNE 1956 A replicated experiment was set up to compare germination of seeds untreated with those alternately soaked and dried in the sun each for 2 days over a total period of 10 days and with those soaked continuously and ex- posed to direct sunlight each day. It was assumed that in the last treatment the seeds would begin to germinate in the water, at which time they would be individually sown. After 125 days the germination of the control was 9.5 percent, and that of the alter- nating treatment 25 percent. None of the seeds in the third treatment had germinated, so they were all then sown. These, after an- other four months had germinated 31 percent. These two pretreatment produced significant- ly higher germination, and the alternate soak- ing and drying treatment is recommended. However, none of the treatments produced the desired result, prompt and complete germi- nation. Storage for 1 year prior to sowing is now being tested. Field Sowing An extensive test of broadcasting and direct sowing of both mahoganies on three sites was laid out in St. Croix during the year. The experiment was only partially successful because of a lack of good seed. With germina- tion negligible in the February and May sow- ings it was assumed that the remaining seed would lose all viability by the time for the final sowing in September. Thus at that time a new seed lot which had been cold stored was used. These seeds, although not much better, gave the only positive results from this study. Results to the end of the year are not final for the September sowings, since the dry season lies immediately ahead. To this time, however, there is an average of one or move seedlings per spot (10 percent germination or more) in all treatments. Broadleaf mahogany germination is as high on the coastal plain as in the interior. Broadcasting on the coast- al plain was comparatively a failure, with less than 1 percent survival. In the more humid mountain, however, broadleaf mahoga- 9 ny showed a germination of 5 percent. It was striking that all of the broadcasted seeds which germinated at this location had fallen in planting holes dug by mistake in these plots and left uncovered. Such seeds gave better results than those spot sown and covered in adjacent plots. This method of showing will be fully tested in the future. Underplanting Underplanting was tested for comparison with broadcasting and direct seeding, t9 test bare rooted West Indian mahcegany stock. and alsc to determine the adaptability of broadleaf mahogany to the coastal plain. The planting was done in September, so only the immediate losses can be reported at this time. The most outstanding finding so iar evident from this study is that sturdy stock of West Indian mahogany can apparently withstand bare rooted planting if special care is taken. In two locations on the coastal plain 3-month survival has been as follows: Treatment Survival Percentage 1. Potted (check) 98 2. Bare-rooted a. Cut back to 2 inch height 86 b. Root pruned, 60 days before lifting 82 c. Defoliated when lifted 65 d. Transplanted 90 days before lifting 83 It is not yet possible to make final com- parisons among the treatments. However, if the trees survive the approaching drought it is certain that some of them will prove more practical than the use of pots. The broadleaf mahogany tested on the coastal plain was all planted with pots. Sur- vival to date has averaged 92 percent. If these trees survive the dry season on the coast the use of more productive species will be preferable to West Indian mahogany. FOREST UTILIZATION RESEARCH About half of the study of machining pro- perties, air-seasoning characteristic and certain 10 related physical properties of 60 native timbers was completed. Some 350 sampie logs of the 60 principal sawlog-size hardwoods of the rain forest were cut during the year. These were cut from more tran 300 sample trees and produced about 20,000 board feet of lumber required for the study. Logs were cut by Forest Service crews, skidded by ox teams to the roads, hand load- ed onto light trucks and hauled to the one available sawinill. Work was complicated by the steep terrain and the insect problem. Logs had to be treated immediately after felling to prevent attack by pin-hole borers. Sample logs of 37 of the species were sawn into boards for testing. Air seasoning, speci- fic gravity and shrinkage determination have been completed for 15 woods and are nearing completion for the other 22 woods. Machin- ing tests and other related tests are nearly completed for 15 woods. All tests on the 50 species are scheduled for completion by June 30, 1956. An additional 10 species may be included, to give almost complete coverage of the principal sawlog species in the local forests. The work has not progressed to the point where definite conclusions can be drawn for each species in the study. However, laborato- ry experience with 37 of the island’s principal sawlog species, has led to certain preliminary impressions. With the exception of two ex- ceedingly light woods, balsa (Ochroma lago- pus Sw.) and ceiba (Ceiba pentandra (L.) Gaertn.) and one exceptionally heavy wood (ausubo), the timbers are quite comparable in weight and appearance to the common saw- log species in the United States. Several species are in superficial appearance and to some extent in structure very comparable to well regarded woods growing on the main- land. Caimitillo (Micropholis chrysophylloides Pierre) and Caimitillo verde (Micropholis gar- ciniaefolia Pierre) are similar to sugar maple (Acer saccharum Marsh); roble (Tabebuia heterophylla (DC) Britton) is similar to oak (Quercus spp.); tabonuco (Dacryodes excelsa CARIBBEAN FORESTER Vahl) is similar to yellow birch (Betula lutea Michx.); laurel geo (Ocotea leucoxylon (Sw.) Mez) and laurel amarillo (Nectandra sinte- nisit Mez.) are like yellow poplar (Lirioden- dron tulipifera L.); and yagrumo macho (Di- dymopanax morototoni (Aubl.) Dene) is like cottonwood (Populus spp.) The general impression that tropical hard- woods are on the average very much heavier and harder than the hardwood of the temper- ate zone does not appear to be borne out in this study. it is possible that this impression has risen from the practice of utilizing prin- cipally the harder and heavier woods that are often more attractive, stronger, and more resistant to insect and fungus attack. It is quite apparent that the tropical hard- woods growing to sawlog-size in Puerto Rico have more favorable shrinkage values than most woods of comparable density in the tem- perate zone. This may be in part due to the very diffuse-porous nature of the woods. The generally favorable shrinkage in volume and in ratio of tangential to radial shrinkage is likely accountable in part for the overall very favorable seasoning characteristics of the timbers under test. With the exception of one species, palo colorado (Cyrilla racemi- flora L.), the woods appear on the average to season with less degrade than a similar group of hardwoods from the temperate zone. The first group of 15 species was season- ed to an air-dry moisture content of 15 to 18 percent in 2 to 4 months during the least humid period of the year. The relative humi- dity during this period averages 60 to 70 percent, as compare to 70 to 85 percent during the wet months. This is, of course, a favor- able factor in preventing degrade through too rapid initial drying. It is likely an important factor in the almost complete absence of sur- face checking in the timbers under test. The humidity is, however, also a primary factor in the susceptibility of many species to attack by sap-stain fungi. This is a constant problem in Puerto Rico. Some timbers must be dipped in a fungicide solution withing a JANUARY - JUNE 1956 itew hours after sawing if sap-stain is to be prevented. Most species are also subject to attack by termites, powder post bettles, or pinhole borers unless protected by an insecti- cide. Experience in preparing test specimens of the 37 timbers and in the machining tests in progress on 15 species indicates the native timbers are, on the average, as workable a: comparable woods in the temperate zone. Se- veral woods have machined more satisfacto- rily than Honduras mahogany, although they are often somewhat harder and heavier and require more power to machine. It appears that a good percentage of the native timbers will machine with less defects than mahogany but that not many will machine as easily as that wood. There appears to be a growing interest in tropical American timbers. A constantly in- creasing number of requests for information on timbers in the West Indies, Central Ameri- ca and South America were handled during the year. These include requests from branches of the Armed Services, other federal agencies, the United Nations, and from foreign governments. Some of these requests involve a special trip to Puerto Rico for those seeking information. The various agencies of the Com- monwealth government now bring most of their problems in forest products to this of- fice. In addition a considerable number of inquiries were handled for private concerns in the United States and Puerto Rico who are interpreted in marketing or utilizing the timbers in this part of the world. A heavy increase in this activity can be expected in ensuing years. 11 A project was begun on a compiling of the existing data for 75 present or potential commercial timbers of the Caribbean. The work is about two-thirds complete and when finished will be published as originally re- quested by the Timber Conference held under the auspices of the Caribbean Commission at Port of Spain, Tr:nidad, in April, 1953. The publication is intended to provide the interest- ed governments, their officials and the timber users of the areas with a summary of the exist- ing information for the principal species of the Caribbean. This is expected to be a factor in the increased sale and better utilization of Caribbean timbers. It is particularly intend- ed to promote more trade in timbers within the region and to increase the local use of the lesser known timbers. PUBLICATIONS A publication entitled “Industrial wood use in Puerto Rico” by F. R. Longwood was published in Vol. 16, Nos. 3 & 4 of the Carib- bean Forester. This publication presented a detailed summary of information collected during more than 500 visits to industrial concerns. It included data on the volume of wood used by species for different products and uses. Both native and imported woods were considered. The quality, grade, and prices of lumber and other wood products were presented. Other related subjects, in- cluding wood waste, plant operation, equip- ment, marketing and the storage of lumber were also reported on in detail. Suggestions were made for improvement in the use of both native and imported material. CARIBBEAN FORESTER Additions to the Flora of St. Barthelemy Pere C. Le Gallo and Joseph Monachino The New York Botanical Garden New York “A check-list of the Spermatophytes of St. Bartholomew” was published by J. Monachi- no in the Caribbean Forester, Vol. 2, No. 1 (1940), pp. 24-47, and No. 2 (1941, pp.49- 66). The report was based chiefly on the collections of Adrien Questel, who in 1942 in- dependently published “The flora of St. Bar- tholomew (French West Indies) and its ort- gin.”. (The date on the title page of Questel’s Flora is 1941, but a notice on the back facing p. 224 states that the printing ended on January 21, 1942. There is also a French edition bearing the same date and pagination but not always the identical text.) In addi- tion to the collections sent to The New York Botanical Garden and determined by Mona- chino, Queste! listed many specimens submit- ted to specialists and deposited elsewhere, Besides presenting a catalogue of the species, the Flora treated the geology, geo- graphy, phytogeography and ecology of the island and the origin and evolution of its plant life. The Check-list, on the other hand presented keys devised to identify the species by the most easily observed characters. These keys have greatly facilitated the identifica- tion of the extensive material recently col- lected by Pere Le Gallo. Our catalogue, to follow includes 172 species which did not ap- pear in the Check-list: 66 of these (signaled by asterisks) are new records based on the recent collections by Le Gallo. The grand total of spontaneous vascular species reported from St. Barthélemy up to date is 598. The exploration by Questel and Le Gallo have elevated St. Barts to a rank amongst th> floristically best known of the islands of the Lesser Antilles. Approximately 440 species of wild vascular plants were enumerated by Questel. The total number cited, 509, includes cultivated plants and 17 thallophytes. In at least one instance the same species was cited separately under synonymous names (Boerhaavia hirsuta and B. coccinea). Questel 517, named Centro- sema pubescens, is merely a hairy form ot C. virginianum. Malpighia martinicensis was re- ported on the basis of the collection numbey- ed 232. But the latter number surely re- presents the same species as Questel 272 cited by both Questel and Monachino as M. punici- folia. The collection Questel 326 cited in the Flora as Lantana camara var. sanguinea (L.) Medik. was identified as L. camara var. acu- leata (L.) Moldenke by Dr. Moldenke. In addition to Questel’s Flora, one other work not previously noted is worth mention- ing as bearing on Sr. Barts: “Flora de la Guadeloupe et Dependences” (fasc. 1, 2, 3, published in 1937, 1948, 1949, respectively) by H. & M. Stehlé and Quentin. Eighteen of the records in fasc. 1 of this work were based on Questel’s collections and were cited (Saint-Barthélemy (Questel)!” These reports were omitted by Questel in his Flora, and Le Gallo suggests that they include collections from St. Martin. The species in question are: Fleurya aestuans (L.) Gaud., Phenax vulgaris Wedd. (exclamation mark omitted in the cita- tion by Stehlé and Quentin), Polygonum punctatum Eli., Achyranthes sessilis (L.) Standl., Celosia argentea L., Microtea debilis Sw., Tribulus cistoides L., chamaesyche arti- culata (Aubl.) Britton) Xylophylla epiphy!- lanthus (L.) Britton, Cardiospermum hali- cacabum L., Corckorus siliquosus L., Trium- fetta lappula L. (“Not found” Questel), Abutilon hirtum (Lam.) Sweet, Hibiscus abelmosckus L., Malachra fasciata Jacq., Sida glutinosa Commers, ex., Cav. Sida rhombifolia L. (“Not found” Questel), Melochia nodiflora Sw. (“Not found’ Questel). Notwithstand- ing, Questel admits (Flora, p. 138) that in 1937 he gave Stehlé a few specimens and “the greater part of these species have not JANUARY - JUNE 1956 been found again.” Pavonia scabra (B. Vogel) Stehlé and Quen. was cited by Stehlé and Quentin from “Saint-Martin et Saint- Barthélemy (ex Urban).” The St. Barts’ record was not located in Urban’s Symb. Ant. 4 and 8. The species was not listed by Questel nor seen by Le Gallo. Stehlé in Bull. Mus. Hist. Nat. 11, 18: 187 (1946), cited Cassia lineata Sw. from ‘“Saint-Barthé- lemy (Saint-Jean). Stehlé and Quentin (fasc. 3, p. 22) attributed the St. Barts citation to Questel’s Flora, p. 116 (French edition). That this record was found- ed upon an error is proved by the fact that C. lineata was corrected to C. obcordata by Questel and the latter name appears on p. 116 of the English edition of his Flora. In the same number oi the Bulletin (p. 108), Stehlé also cited (Galactia longifolia (Jacq.) Benth “Saint-Barthélemy (Stehlé).” However, 55. Barts was omitted for the species by Stzh!é ond Quentin in their publication of a later date (fasc. 2, p. 111). Fleurya cue the island. The ensiform leaves are about 60 cm. long and 3.5 cm. broad, finely spinu- lose serrulate on the margins. COMMELINACEAE Callisia repens L. Q. LILIACEAE Aloe vera L. “naturalized” Q. ‘“Largement naturalisé dans toute Vile” Le G. AMARYLLIDACEAE Agave dussiana Trel. Q. (det. Trelease). “Fréquents” Le G. Agave sisalana Perrine. Q. “Fréquents” Le G. Crinum amabile Donn. “Naturalized”’ Q. “Ne s‘eloignent guére des jardins” Le G. Furcraea tuberosa Ait. Q. (det. Trelease). “Plutot rare’ Le G. Zephranthes carinata (Spreng.) Herb. “Es- caped” Q. “Ne s’eloignent guére des jardins” Le G. Zephrantes aurea Baker. “Escaped” Q. s’eloignent guére des jardins” Le G. (det. Trelease). “Ne ORCHIDACEAE Epidendrum bifidum Aublet. 812 (morne La- rigot), 1000 (Merlette), 2022 (Roche Marrone), 2086 (Anse Chauvette), 2175 (Anse de Cayes), 2262 (Merlette). Q. Charles Schweinfurth wrote in September, 1954 that after critical study he decided that 1000 and 2022, as well as 2175 which previously he had reported as E. oliva- ceum Cogn., are referable to the variable E. bidifum. Questel 36) also should be re- 17 ferred to this species. Le Gallo noted that almost all the Epidendrum on the island are like 2175; the species is quite common on exposed rocks. *Oncidium intermedium Bertero ex Spreng. 128 (morne a Diaquot, Vittet), 810 (morne Larigot): 2389 & 2392 (morne a Poune). Le Gallo 2389 was checked by Charles Schweinfurth, April, 1956. Ques- tel cites O. gutiatum (L.) Reichb. f. for St. Barts (Le Rhin), but the species may be this instead. Stenorrhynchus orchioides (Sw.) L. C. Rich. Q. ‘“Malgré toutes mes recherches, sur- tout auprés des petites mares de St. Jean, je n’si jamais vie cette plante a St. Barth.” Le G. ‘The Questel St. Barts’ record is not supported by any specimen in the herbaria at N. Y. Bot. Gd., Harvard, and U. S. Nat. Mus. URTICACEAE Fleurya aestuans (L.) Gaud. 2376 (on walls, presbytére, Gustavia, 1 Janv. 1955). “(Questel)!” Stehlé & Quentin 1:184. Not in Q. OLACACEAE Schoepfia schreberi J. F. Gmel. 728 (sentier entre Vittet et Grand Fond), 787 (chemin de Vittet a Grand Fond), 2074-2076, 2375, 2377 and 2379 (St. Jean). Q. A sterile specimen previously collected by Forsstrom is probably of the same species. POLYGONACEAE Coccoloba venosa L.—C. nivea Jack 2325, 2327, 2328 & 2371 (St. Jean; very rare, seen at one place; 2371 checked by R. A. Howard). CHENOPODIACEAE Chenopodium ambrosioides L. Q. ‘“Natura- lisé autour des habitations” Le G. AMARANTHACEAE Achyranthes repens L. 33 & 102 (1 Orient). Q. Achyranthes urbani Standl: 106 (Ilet de Fré- gate, en face de !’Orient), 233 (ans2 de 18 VOrient), 542 (Mangeant). The stami- nodes were examined in 106 and 2338. Iresine celosia L. 385 (Vittet), 390, (Man- geant), 408 (Anse Gouverneur), 677 (Vit- tet), 711 (Orient), 2347 (Vittet). Q. NYCTAGINACEAE Mirabilis jalapa L. “Escaped” Q. Pisonia subcordata Sw. 131 & 641 (Chemin de Orient a Gustavia, St. Jean). Q. PHYTOLACCACEAE Trichostigma octandrum (L) H. Walt. Q. “General dans l’ile, mais de place dans les coulées ambreuses ou les crevasses des mornes” Le G. AIZOACEAE Mollugo verticillata L. 103 (Grand Fond), 393 (Mangeant,) 465 (Frégate), 2164 (Grand Fond), 2231 & 2232 (Mangeant). Sesuvium maritimum (Walt.) B.S.P. Q. PORTULACACEAE * Talinum paniculatum (Jacq.) Gaertn. 273 (seulement 4 morne de Vittet). PAPAVERACEAE Argemone mexicana L. Q. “Trés commune comme rudérale dans toute ile’ Le G. BRASSICACEAE Lepidium virginicum L. Q.“Général” Le G. CAPPARIDACEAE Capparis coccolobifolia Mart. 205 & 2047 (Orient, Diboque). Q. Cleome gynandra L. Q. l’Orient, Corossol’”’ Le G. * Morisonia americana L. 198 (l’Orient, vieux chemin de Grand Fond), 267 (morne de Petite Saline), 2046 & 2048 (1’Orient, 2080 & 2060 (1’Orient, Diboque). CRASSULACEAE Bryophyllum pinnatum (Lam.) Kurz. Q. “Gé- neral et commun par places” Le G. “Occasionnelle, AMYGDALACEAE Chrysobalanus icaco L. Q. “St. Jean, Grande Saline, Anse des Cailles, morne de Petite Saline, morne de Vittet” Le G. CARIBBEAN FORESTER MIMOSACEAE Acacia guadalupensis DC. 433 (1l’Orient), 610 (morne de Petite Saline). Previously col- lected by Questel at St. Jean and report- ed as A. riparis H.B.M. CAESALPINIACEAE Cassia bicapsularis L. 384 (Vittet), 519 & 727 (pres cimetiére de St. Jean). * Cassia chamaecrista L. 457 (St. Jean, fide Amshoff), 2444 (St. Jean), 2523 (Siréne, hauteurs Saline), 2535 (St. Jean), 2552 & 2553 (Grande Saline), 2561 (St. Jean). * Cassia emarginata L. 130 (Anse Toiny), 379 (Vittet), 755, 791 & 982 (Anse Toiny), 756, 757 & 775 (Anse Toiny, fide Amshoff). Cassia glandulosa var. swartzii (Wikstr.) Ma>- bride. St. Barthélemy is the type locality. Cassia obcordata Sw. ex Wikstr. 418 (Vittet), 553 & 579 (morne entre Saline et St. Jean), 660 (Chateau), 693 (St. Jean), 2308 (llet ouest de Fourchu). Q. Cassia occidentalis L. Q. “Commun” Le G. Delonix regia (Bojer) Raf. “seen” Q. ‘“natura- lisé”’ Stehlé 1. c. 186. Haematoxylon campechianum L. 368 (Gusta- via). Q. Hymenaea courbaril L. 583 (morne du Rhin). Q. FABACEAE * Aeschynomeme americana L. 370, 482 & 2198 (lV’Orient 2522), 2545, 2559 & 2560 (Grande Saline). 370 was checked by Velva E. Rudd; 482, fide Amshoff. * Crotalaria lotifolia var. eggersii H. A. Senn. 376 & 394 (Mangeant), 419 (Anse Toiny), 528 (Grande Saline), 679 (Man- geant), 956 (Seine Anglais), 1017 & 1050 (Chauvette), 2035 (Mangeant), 2166 & 2213 (Cul de Sac). Desmodium canum (Gmel.) Schinz & Thel- lung. 545 (Petite Saline), 669 (morne de Vittet), 2040 (Petite Saline). Q (as “PD. supinum DC.’”). * Desmodium scorpiurus (Sw.) Desv. 1045 pro parte (Vittet). _ Desmodium tortuosum (Sw.) DC. 171 (Anse JANUARY - JUNE 1956 de l’Orient), 2324 (Vittet), 23888, 2427, 2429, 2438, 2439 & 2445 (Mangeant). Q. * Galactia dubia DC. 2083 (Anse Gouver- neur), 2155 (Grand Fond), 2234 (Coup=2- Gorge), 2236 (Grand Saline). Galactia sp., variety of G. dubia DC? 369 (7 Orient, 25° Jan: 1952). 371.& 540 (Mangeant, 17 Jan. 1952), 818 (rochers prés de |’Anse aux Flamands, 4 Juin 1952), 1026 & 1028 (pointe de Chauvet- te, rochers maritimes, ca. 20 m. alt., 30 Sept. 1952), 2220 (Vittet, rochers basal- tiques, 170 m., 15 Nov. 1953), 2268 (Anse 4 Toiny, falaises, entre rochers, 15 m., 11 Juil 1954), 2286, 2302, 2387, 2426, 2450, 2528, & 2534 (Marigot, sur murette 4 Sisal, 30-70 m., Sept. 1954,Nov. 1955). The members of G. dubia complex are very variable in leaflet size and shape, in pubescence, and also in the width of the legume. A critical study of the species and its allies is required. The St. Barthe- lemy specimens are 3-foliolate (some in- dividual leaves possibly unifoliolate), the leaflets oval or orvicular to obovate, 1-2.8 cm. long, usually emarginate at apex, glabrous above except for a line of hairs on midrib, silvery strigulose beneath, hairs dense and closely appressed, the young stems similarly silky; flowers and buds 1-4 to each inflorescence, the calyx appressed white-hairy, the legumes 2.5-4.5 mm. broad, white-pubescent with mostly appressed hairs. The leat-pubescence suggest some material of the unifoliolate G. numularia Urban from St. Martin. Our plant somewhat also suggests G. uni- flora Urban from the Bahamas. Accord- ing to Fawcett & Rendle (Fl. Jamaica), the latter is possibly only a small form of G. dubia. Piscidia piscipula (L.) Sarg. Q. “L’un des arbustes les plus communs de St. Barthélemy” Le G. * Teramnus labialis Spreng. parte (l’Orient). ERYTHROXYLACEAE Erythroxylon brevipes DC. “Forsstrom (hb. holm.); — E. ovatum Eggers, 426 &713 pro non 19 O. E. Schulz in Urb. Symb. Ant. 1907. ZYGOPHYLLACEAE Guaiacum officinale L. 427 (Orient), 555 (taillis a Cactacées et Acacias, Coupe- Gorge). Q. RUTACEAE Citrus auraniijolia (Christm.) Swingle. “Na- turalized” Q. Zanthoxylum spinifex (Jacq.) DC. 786 (che- min de Vittet, a Grand Fond, 20 Mars 1952). Q. The Le Gallo specimen is a form or variety without spines; stems not as strongly zig-zag as is usual for the species. SURIANACEAE ote Anse Toiny, Suriana maritima L. Q. Forsstrom. Jean, l’Orient, Marigot, Grand Fond, etc.” Le G. BURSERACEAE Bursera gummifera L. Q. “Commun” Le G. MALPIGHIACEAE * Stigmaphyllon diuersifolium (H.B.K.) A. Juss. = S. ledifolium (H.B.K.) Small. 808 (morne Larigot), 2212 (Cul-de-sac), 2247 (Petite Saline), 2276 (St. Jean). The two specific spithets were published in Banisteria on the same date and page. The taxa were first united by Jussieu (Monographie Malpig. 1844), and _ his choice of name must be followed (Article 67 of the International Code, 1952). EUPHORBIACEAE Acalypha chamaedrifclia (Lam.) Muell. Arg. Q. * Aklema petiolaris (Sims) Millsp. — Euphor- bia petiolaris Sims. 2171 (1’Orient). * Croton nummulariaefolius A. Rich. 304 (morne a Poune, 3 Oct. 1951), 313 (morne de Grand Fond, rochers, 250 m. alt. 11 Oct. 1951), 534 (Chauvette, 25 Oct. 1951), 640 (Morne de Grand Fond. rochers, 250 m. alt., 11 Ot. 1951), 718 & 724 (au dessus du Grand Platon, pres de Grand Fond, sur rochers, 14 Mars 1952), 1062, 1063, 1064 and 1068 (Grand Platon, rocailles, rochers dacite, 150-200 m. alt., 30 Oct. 1952), 2081 & 2082 (Grand Fond, rochers, falaises du Grand Platon, 100 m., 15 Apr. 1953). Form or variety with pubescence-stellae on stem closer, rays shorter, center ruby- brown; pedicels very short; sepals in fruiting specimens substapulate, narrow- ed at base, about 1.8-2 mm. long. Chamaesyche hypericifolia (L). Millsp. = Euphorbia hypericifolia L. 246 (VOrient). “Given to M. Stehlé in 1937” Q. “Saint- Barthélemy (Questel)!” Stehlé & Quen- tin 1:68. * Chamaesyche thymifolia (L.) Millsp. = Euphorbia thymifolia L. 2178 (St. Jean, terrains sablonneux bord de la mer), 2226 (St. Jean, jardin pres d’un_ rocher). Fruits with longer more spreading hairs than is usual for the species. Euphorbia tirucalli L. “Escaped & subsponta- neous” Q. * Gymnanthes lucida Sw. 98 (morne de Etoile), 258 & 619 (morne de Vittet), 653 (morne de Il’Etoile), 799 (Vitiet, mornes de Dévet), 1080 (1’Orient.) Hippomane mancinella L. Q. “Commun sur le bor des plages et parfois a l’intérieur du pays” Le G. Phyllanthus swartzii Kostel. Questel speci- mens previously named P. niruri L. were determined as P. swartzit by Grady L. Webster in 1953. Ricinus communis L. Q. SAPINDACEAE Melicocca bijuga L. Q. * Sapindus saponaria L. 30 (morne de Vittet, bois Chapelet, Simonet), 559, 699 (morne de Vittet). RHAMNACEAE Colubrina ferruginosa Brong. 521, 524 & 529 (Cul de Sac, rochers madréporiques au dessus de la grande Voute), 717 & 721 (Anse Maréchal, bordure de la mer), 735, 737 & 784 (Cul de Sac, rochers madré. | CARIBBEAN FORESTER por.ques au dessus de la grande voute), 789 (Grande Saline), 792 (Cul de Sac, la grande Voute, rochers calcaires), 804 (Cul de Sac, au dessus de la Grande Saline). Colubrina reclinata (L’Her.) Brongn. 254 (fond de VAnse, Orient, rochers), 259 (Anse de l’Orient), 561 (fond de l’Anse, VOrient)}, 572 (mornes au fond de VOrient), 577 VOrient), 622 (fond de Anse, rochers), 663 (mornes de Saint Jean), 702 (Vittet, morne a Diaquot), 788 (Grande Sealine, rochers), 999 (Anse aux Gascons), 2019 (Vittet). 2332 & 2349 (Mangeant). Note: 702 & 2349 (C. reclinata) and 784 & 804 (C. ferruginosa) are flowering specimens fairly typical of the species. The other collections cited under C. reclinata are without open flowers, and some oi then may actually be shade forms of C. ferruginosa. The two species are quite similar in essential details and perhaps not clearly distinct. Krugiodendron ferreum (Vahl) Urb. 172 (morne, environ de JOrient), 203 (morne de Vittet), 301 (morne de Petite Saline), 574 (L’Orient, morne au dessus de Ecole), 576 (morne de Vittet), 580 & 582 (Le Rhin, entre Anse Gouverneur et Gustavia), 666 (morne de Vittet, flanc nord), 798 (Grande Saline, mornes). VITACEAE Cissus sicyoides L. Q. “Commun partout dans Vile” Le G. TILIACEAE Corchorus siliquosus L. 482 (Anse Gouver- neur), 2624 (Chemin de Saline - Lurin), 9352 & 2533 (Lurin). ‘(Questel)!” Stehlé & Quentin 1:117. No* in Q. MALVACEAE Abutilon indicum (L.) Sweet. 422 (L’Orient). Gossypium hirsutum L. “Spontaneus” Q. Paritium tiliaceum (L.) A. L. Juss. 622 (En bordure de l’Anse de lOrient). Sida aggregata Presl. Q. JANUARY - JUNE 1956 BOMBACACEAE Ceiba pentandra (L.) Gaertn. “Only two or three large trees remain” Q. STERCULIACEAE Melochia nodiflora Sw. 421, 687 & 697 (Orient, Diboque). “(Questel)!” Stehlé & Quentin 1:114. “Not found” Q. CANELLACEAE * Canella winterana (L.) Gaerta. 2551 (Lu- rin, taillis, 150 m. env.; sterile). VIOCLACEAE *“ Hybanthus caribaeus Urb. 729 (Marigot), 934 (Anse Chauvette), 957 & 978 (Saint- Caillu, parmi Crotons et Cactées), 1019 1020 & 1030 (pointe de Chauvette), 2012 (Pointe Felix). Doubtfully distinct trom H. linearifolius; 729 & 978 conform rather closely with a syntype of H. Cari- baeus (Duss 2959). The leaves and habit are variable. Hybanthus linearifolius (Vahl) Urb. Q. Hybanthus portoricensis Urb. 377, 462 & 464 (Mangeant), 519 & 531 (Grand Cul de de Sac, pointe du Vente). Both this species and H. caribaeus need study. Le Gallo suspects that Hybanthus in St. Barts modifies its size according to ha- bitat. In very sunny, dry, rocky soil it is small, hardly a few centimeters in length. In the shade or in the Opuntia brush, it measures about one or two centi- meters. Both the small and the large specimens have flowers with a yellow spot in the center and pale rose-colored lower petal. PASSIFLORACEAE Passiflora foetida L. “Gustavia, Anse des Cayes, camaruche” Le G. CARICEAE Carica papaya L. ‘‘Subspontaneus” Q. CACTACEAE Cereus intortus Mill. Q. ”Commun” Le G. Cephalocereus nobilis (Haw.) Britt. & Rose. Q. “Trés commun” Le Gallo. df Consolea rubescens (Salm-Dyck), Lemaire. Q. “Dans les caps escarpés, rocailleux” Le G. Neomammilaria nivosa (Link) Britt. & Rose. Q. “Ilets Fourchu, Coco, Frégate, Pointes Colombier, Mangeant, Toiny, etc.” Le G. Opuntia dillenit (Ker-Gawl) Haw. Q. Opuntia triacantha (Willd.) Sweet. Q. Opuntia tuna (L.) Mill. Q. MYRTACEAE Anamomis fragrans (Sw.) Griseb. 182 (Grand Voute a Mangeant), 250 morne a Dia- quot), 381 (Vittet; sterile), 565 (morne 4 Diaquot), 633 (Grande Voute a Man- geant), 636 (morne de Petite Saline), 676 (Vittet; sterile), 1083 (St. Jean). * Eugenia cordata (Sw.) DC. 471 (morne de St. Jean; sterile; reported by Am- shoff), 587 (morne entre Saline et St. Jean), 819 (Morne Larigot), 996 (Petite Saline), 1091 (Morne Larigot), 2023 (Petite Saline), 2027 (Petite Saline; sterile; reported by Amsho‘f), 2201 (morne de Petite Saline). | * Eugenia maleolens Pers. 428 & 451 (Arse Gouverneur; former reported by Am- shoff), 1087 & 1088 (Grand Bois), 2041 mornes de l’Etoile). It appears that the familiar name Eugenia buxifolia (Sw.) Willd. (1800) of the West Indies must be discarded, for it is a later homonym of E. buxifolia Lam. (1789) described from Reunion. If Urban’s synonymy in Engl. Bot. Jahr. 19:637 (1895) is correct and complete, our plant must be called E. maleolens Pers. (1087). Eugenia monticola (Sw.) DC. Q (877, wooded hillsides, St. Jean.) “‘Pass encore vu dans les collines foisées St. Jean, j’ai vu E. ligustrina E. rhombea, et alors E. buxi- folia” Le G. * Myrtus orbicularis (Berg) Burret. 525, 733, 793, 1042, 1047 & 1048 (Cul de Sac, Grande Voute, rochers madréporiques). 1047 was compared with L. C. Richard’s type of Eugenia orbicularis Berg at Paris by M. Pichon who reported: “Je puis vous affirmer que l’identité des deux est compléte.” Le Gallo also collected the species in Anguilla (2492, 2508). M. anguillensis Urban appears to be con- specific. Amshoff communicated: “Myr- tus orbicularis, represented in the collec- tion of Le Gallo by the nrs. i047 and 2067, is indeed conspecific with Myrtus anguillensis Urban. I have now _ seen specimens from Anguilla, St. Barts and the Dutch West Indies.” COMBRETACEAE Terminalia cattapa L. Q. ‘‘La plante se natu- ralisé lentement” Le G. APIACEAE “Naturalized” Q. THEOPHRASTACEAE * Jacquinia berterii Spreng. 1058 & 1066 (Grand Platon, dans rochers, bois, tail- les). Foeniculum vulgare Mill. SAPOTACEAE Bumelia obovata (Lam.) A. DC. 120 (mornes de St. Jean, bois de Monte au Ciel), 293 & 606 (mornes environs de | Orient), 618 (sommet du morne de Vittet), 642 (mornes de St. Jean), 731 (chemin entre Vittet et Grand Fond), 2118 (Cul-de- Sac), 2125, 2126, 2134 & 2156 (l’Orient). Forsstram. Manilkara_ zapotilla spontaneous” Q. OLEACEAE Jasminum azoricum L. 566 (haies, chemin de VOrient). “Escaped” Q. APOCYNACEAE * Urechites lutea (L.) Britton. 526 (Anse Toiny), 803 (Cul de Sac, dessus Grande Voute), 681 & 734 (Anse Toiny), 794 (Anse a roches basaltiques), 972, 992 & 993 (mornes de Anse a Toiny), 1049 Anse Toiny). (Jacq.) Gilly. ‘“Sub- CONVULVULACEAE * Calonyction tuba (Schlecht.) Colla. 2176 (Anse aux Lézards; seule localité connue). Evolvulus glaber Spreng. 129 (route de Sa- line), 397 pro parte (St. Jean), 494 (Vit- tet, morne a Diaquot), 527 (Cul de Sac, CARIBBEAN FORESTER dessus de la Grande Voute), 539 (Man- geant), 544 (Petite Saline), 726 pro parte (pres cimetiére de St. Jean), 983 (ter- rains rocailleux), 2139 (Marigot), 2207 (’Crient). Q. Evolvulus nummularius L. 2142 & 2169 (Anse aux Lézards), 2177 (Anse de Cayes). Evolvulus sericeus Sw. 315 (Grande Saline), 935 (Chauvette), 964 (entre Saline et Seine Anglais), 968 (morne Larigot), 977 (pres Seine Anglais), 1033 (Pointe de Chauvette), 2098 (l’Orient), 2110 (Pichotte), 2227 & 2323 (Mangeant). Q. Exogonium solanifolium (L.) Britton. 359 (Chauvette), 1084 (Camaruche), 2193 (l’Orient). Q. Ipomoea nil (L.) Roth. Q. “Ca et 14” Le G. Ipomoea pes-capra2 (L.) Roth. Q. “Trés commun du bord de mer autor de Vile” Le G. * Ipomoea quinquefolia L. 2173 & 2200 (V’Orient, found once). Ipomoea triloba L. Q. “Ca et 14” Le G. * Jacquemontia jamaicénsis (Jacq.) Hall. f., var. 742 (Pointe la Caye, Anse de Cayes, 18 Mr. 1952), 743 (Anse de Cayes, bord de la mer, O m., 18 Mr. 1952), 2145 (Anse aux Lézards, rochers maritimes, 10 m., 10 Dec. 1953), 2174 (Anse de Cayes, rochers maritimes, 20 m., 10 Dec. 1953; only one locality known.) The shape and texture of the leaves and the habit of the plant are as in J. cayensis Britton; our variety differs in the marked density of leaf indumentum. At least thre2 species are involved, the two already mentioned and J. reclinata House ex Small. It is suspected that these species comprise but a single variable one with several races, forms or varieties. The Le Gallo specimens were not matched with any material at The New York Botanical Garden. Jacquemontia nodiflora (Desr.) G. Don. 397 St. Jean), 2195 (Cul de-Sac), 2202. 2216 & 2246 (Petite Saline). Jacquemontia obcordata (Millsp. ) Hous:, N. Y. Mus. Bull. 233-234:63 (1921) = JANUARY - JUNE 1956 Convolvulus obcordatus Millsp., Columb. Mus. Bot. 2:88 (1900) = Jacquemontic subsalina Britton, in Britton & Wilson, Sci. Surv. Porto Rico and Virgin Islands 6: 106 (1925). 2253 (Orient prés du presbytére, 15 m., 12 Mars 1954). Ques- tel 373 (Grande Saline, 1938), cited in the Check-list as J. ovalifolia (Vahl), Hall. f., is the same. It has not been pos- sible to check the type of Convolvulus ovalifolius Vahl. Operculina dissecta (Jacq.) House. 294 & 607 (L’Orient; assez commun dans les halliers de toute Vile). Q. HIDROPHYLLACEAE Nam2 jamaicensis L. Q. BORAGINACEAE Cordia dentata Poir. Q (as “Cordia alba” in the Flora) cited by Johnston. Cordia glabra L. Q. Cordia globosa (Jacq.) H.B.K. 563 (chemin de Camaruche). Q. Cordia myxa L. —‘“‘Escaped” Q. ‘En voie de naturalisation non loin des lieux habités.” Le G. Cordia sebestena L. Q. “Rarement échappé (Anse de St. Jean)”’ Le G. * Heliotropium microphyllum Sw. ex Wikstr. 2093 &2225 (Pointe des Négres, falaises calcaires du littoral; a very rare plant on the island). Four Urban species are placed in the synonymy of H. microphyl- lum by Johnston. Our plant also match- es fairly well with specimens of H. imbri- catum Griseb. from Cuba and H. ina- guense Britton from the Bahamas. Heliotropium parviflorum L. 188 (Anse de VOrient). Forsstrom. Q. * Rochefortia acanthophora (DC.) Griseb. 806 (Pointe Blandin taillis), 2386 (Mari- got, taillis, 70 m. environ). Tournefortia microphylla Bert. ex Spreng. 268 & 614 (pres du presbytére de ]’Orient). Q. The Forsstrom collection was located; it belongs with this species, which probably is merely a small-leaved xero- phytic form of T. volubilis L. Tournefortia volubilis L. 382 (Mangeant). bo (us) BERBENACEAE Lantana urticaefolia Mill. Q (as L. camara var. crocea (L.) Jacq.). Phyla nodiflora (L.) Greene. Q. Phyla nodiflora var. reptans (H.B.K.) Mol- denke. 985 (l’Orient). Q. LAMIACEAE Leucas martinicensis (Jacq.) R. Br. Q. * Marsypianthes chamaedrys (Vahl) Kuntze. 2383 (Grand Fond). SOLANACEAE Lycium tweedianum var. chrysocarpum (Urb. & Ekm.) C. L. Hitchcock. 1041 (Mari- got). Q. Solanum argillicolum Dunal. Q. BIGNONIACEAE * Crescentia linearifolia Miers. 960, 961 & 967 (morne de |’Anse a Toiny). Distictis lactiflora (Vahl) DC. ‘Introduced about 1860 and escaped” Q. ACANTHACEAE * Anthacanthus spinosus (Jacq.) Nees. var. 311 (morne de Grand Fond, 250 m. alt., flanc nord), 1057 (Grand Platon, sous bois et rocailles, 150-200 m. alt. 30 Oct. 1952), 2180 (Grand Platon, terrains dacitiques 200 m., 12 Nov. 1953.) Calyx and pedicel glandular. 311 is sterile, otherwise the same as 1057 and 2180. * Blechum brownei Juss. 2380 (L’Orient, Coupe-Gorge, fosses, 20 m. env.) Justicia eustachiana Jacq. 196 & 420 (Vittet), 435 (Orient), 537 (Mangeant), 629 (Vittet; checked by E. C. Leonard at the U.S.N.H.), 689 (l’Orient), 1076 (morne de l’Orient), 2101 (Anse a Toiny), 2313 (Ilet Fourchu), 2337 (morne Larigot), 2351 (Vittet). Justicia periplocifolia Jacq. Q. RUBIACEAE * Borreria laevis (Lam.) Griseb. 361 (Man- geant), 2315 (Grande Saline). Ernodea litoraris Sw. 722 & 723 (Grand Fond), 2181 & 2209 (Grand Platon). Q. Exostema caribaeum (Jacq.) R. & S. 185 24 (morne au dessus de |’Orient), 191 (Vit- tet), 487 (l’Orient), 501 (Vittet), 617 (morne de Petite Saline), 633 (morne au dessus de |’Orient, 704 (1’Orient). Q. Guettarda parviflora Vahl. 269 (environs de VOrient), 955 (bois de Seine Anglais), 613 (environs de l’Orient). Q. Guettarda scabra (L.) Lam. 802, 821 & 822 (morne Larigot). * Qldenlandia callitrichoides Griseb. (1’Orient). * Psychotria microdon (DC.) Urb. 987 (prés étang de St. Jean). Strupfia maritima Jacq. 520, 523, 736 & 795 (Cul de Sac, Grand Voute). 2119 CAPRIFOLIACEAE Sambucus simpsonii Rehder. ‘‘Naturalized” Q. “Cette plante peut se trouver dans Yun on l’autre enclos de Gustavia, mais n’es pas naturalisée” Le G. CUCURBITACEAE Cayaponia americana (Lam.) Cogn. 386 & 667 (Vittet). Cucumis anguria L. “A Vétat sauvage en quelques endroits” Le G. Cucurbita moschata Duch. ‘Naturalized”’ Q “Nest pas naturalisé’”’ Le G. Momordica charantia L. 2078, 2091 & 2121 (Grand Fond; la seule localite). ‘‘Saint- Barthélemy (ex Cogniaux)’’ Stehl4 & Quentin 3: 128. CARIBBEAN FORESTER ASTERACEAE Ageratum conyzoides L. 378 (Vittet). Ambrosia hispida Pursh. 570 (vieux cimetiéze de Public). Q. Borrichia arborescens (L.) DC. Q. Conyza canadensis var. pusilla (Nutt.) Cronq. Q. Eclipta alba (L.) Hassk. 364 (l’Orient), 475 & 564 (St. Jean). Q. Emilia sagittate (Vahl) DC. 2443 (chemin d2 Vittet). Q. Eupatorium adoratun L, 2256 (Vittet). Q. Lagascea mollis Cav. Q. * Melanthera nivea (L.) Small. 632 (l’Orient). Pectis febrifuga H. van Hall. te), 2250 (St. Jean). Q. Pectis humifusa Sw. 518 & 569 (Cul de Sag, pointe du Vent), 2100 (Anse To’ny). Q. Pectis linifolia L. 362 (Mangeart). Q. Synedrella nodiflora (L.) Gaertn. 2217 (VOrient). Q. Vernonia albicaulis Pers. 114 (Mangeant), 195 (VOrient), 431 (Anse Gouverneur), 1086 (chemin de Saline a Lurin), 2017 & 2025 (chemin de Saline), 2257 (Vit- tet). Q. Vernonia cinerea (L.) Less. 468 & 709 (Mangeant), 2451 (chemin de Vittet). Q. Wedelia calycina L. C. Rich. 181 (Marigot), 363 (Mangeant), 634 (Marigot), 674 (Mangeant). Q. Forstrom. Wedelia gracilis L. C. Rich. Q. Wedelia parviflora L. C. Rich. Q. 169, 187 & 942 (Chauvet- JANUARY - JUNE 1956 i) 1 Forest Preservation in the Windward Islands H. FRASER Conservator of Forests St. Lucia, B.W.L. The benefits which forests confer on their owners and on the community in general are direct and indirect. Direct benefits include the timber, poles, firewood, and the minor products such as fibres, resins, and tanning materials, which the forests provide. The in- direct benefits are the effects which forest areas have in conserving the oil and water sup- plies, and in providing shelter from wind. The indirect benefits of forests will be dealt with first, for in the Windward Islands: as elsewhere in the Caribbean, the in- direct benefits are fundamentally of greater importance that the direct. Timber and other products of the forest can be imported if ne- cessary but nothing can replace the benefits which the forest itself confers in preserving an equable climate and in conserving soil and water. ‘There has been much controversy on the question of the effects of forests on rain- fall. In some quarters it has been proved that forests have no effect on rainfall and that under certain conditions the planting of trees may even cause springs and streams to dry up. This may occur in places subject to long periods of drought where excessive transpira- tion in a dry atmosphere removes more mois- ture. There can be no doubt, however, that the forest covered mountain ranges of the Wind- ward Islands contribute towards the heavy rainfall which occurs in these areas. This is not due entirely to the fovests them- selves but to their situation. The mountain ranges, rising abruptly from the sea to heights of over 3,000 feet. cause an upthrust of the moisture laden winds from the Atlantic and rapid cooling at these elevations. This pheno- menon, aided by the presence of the forest, results in heavy precipitation of rain. Even in the dry season the cooler air over the forest causes cloud formation with occasional show- rs at the higher altitudes. The forest cover sreserves the crumbly texture of the soil, which together with the pus layer, readily ab- corbs and holds the water allewing it to per- colate slowly to emerge late? a3 springs and streams giving a resular flow throughout the year. It has been observed that c’earing of forest in heavy rainfall areas at high altitudes causes rapid changes in the composition and structure of the soil. Organic matter in the humus layer is lest, inorganic salts are leached out, the soil becomes laterised and loses its porosity, and becomes useless for the produc- tion ot agricultural crops. The loss of porosi- 7 res ults in a rapid runoff causing erosion, flooding, and silting up of rivers, streams, and reservoirs. Such cleared lands invaded with fern and eventually palms but it takes many years for the forest cover to be restored. The forests are also of great benefit in breaking the force of the wind an it is only by Fs) thus preserving moist conditions that the preduction of cocoa, coffee, nutmegs, bananas, and other agricultural crops is possible. The apparently dry conditions which prevail along the windward coasts of Grenada, St. Vincent, St. Lucia, Dominica, and throughout the low- lying islands of the Grenadines, are not due so much to the lack of rain as to the effects of the constant winds blowing in from the sea. Annual rainfall in these areas is seldom less than 40 inches. Elsewhere in the tropics, on equally light soils, a similar rainfall supports a dense natural vegetation, whilst the vegeta- tion on parts of the windward coast resembles the type one would expect to find with a rain- fall ef under 20 inches in less exposed situa- tions. It is therefore apparent that the es- tablishment of well-sited windbreaks wouid have a most beneficial effect on the productive capacity of the land either for the growing of crops or for grazing. The larger landowners in the Windward Islands fully appreciate the indirect benefits of forest and but for their efforts in the past in protecting their forest lands, the islands would have suffered much more severely from landslides erosion, periodical flooding, and ' shortage of water. The danger arises when the large estates are broken up and the smal- ler landowners are obliged to clear more forest in order to obtain sufficient land for cultiva- tion. The possession of land carries with it great responsibilities and it should be the aim of every landowner to leave his estate in a better condition than when he acquired it. The protection of large tracts of forest, on which the welfare of the community depends, is normally the function of the State, but in his own interests, a good landowner will protect his forests. He realizes that this is necessary and beneficial to the successful cul- tivation of his agricultural crops and for the maintenance of his water supplies. For ex- ample, the tops of hills and ridges should be left under forest, steep slopes should be left uncleared, and valley bottoms kept under a forest cover to prevent loss of water and pol- lution. Belts of forest should be retained at intervals along the contours of cultivated slopes to prevent excessive loss of soil, and to preserve moist conditions by breaking the wind. In some cases where cold drying winds sweep down valleys, belts of forest up and down the slopes will provide shelter. In addition to the indirect benefits of forest and the importance of forest protection, it should be appreciated that although a forest may be conserved primarily for its protective functions, it can at the same time provide direct benefits in the form of timber, firewood, and minor produce. A forest is a living thing and never remains in a static condition. In a natural forest trees reach maturity, die, and fall, and their place is taken by younger trees which have previously been suppressed and have been awaiting light and space to get away. Some seeds lie dormant in the ground until an opening in the canopy affords the light and heat required for their germination. CARIBBEAN FORESTER It is therefore justifiable to remove mature trees before they die, and to utilize the timber instead of leaving it to rot on the ground. A tropical rain forest is made up of a great varie- ty of trees of all ages and often there are too many of them competing for light, moisture, and nourishment from the soil. Consequently they are not growing as vigorouly as they should and a judicious thinning out would result in more rapid growth and a higher yield. By removing the poorer kinds and utilizing them as poles or firewood the better species of timber trees would be encouraged and the condition of the forest improved. A forest can be compared to a factory where each individual tree is a workman pro- ducing wood. Our virgin rain forest is like a factory in need of re-organization. There are too many old workmen, some already senile, who have long since ceased to produce wood. They stand in the way of advance- ment for the younger men below, but these also are losing their vigour as they are con- stantly obstructed by the old men. There are too many of them; they get in each others way and have insufficient room to work. Below them are a number of apprentices, many of whom would become good workers if given a chance. There is also among them a number of undesirable characters who try to thrust themselves forward, whose work is inferior and tends to lower the general standard of production. Finally, there are too many hangers-on, creepers, and parasites, who do no productive work themselves and sabotage the labour of the good workmen anxious to get on with the job. A complete re-organization is necessary. First of all, the old men must be removed to make room for the more efficient younger men below. Some of these will have to go too, for they have become lazy and reduced their out- put through suppression and lack of incentive. They will never become efficient workmen and must give place to their more vigorous com- panions. Among the apprentice all the un- desirables must go and every encouragement given to the strong and efficient workers. JANUARY - JUNE 1956 Hangers- on cannot be tolerated and must be ruthlessly eradicated to prevent their inter- ference with the skilled and conscientious workmen. The process of re-organization, however, must be carefully and tactfully carried out by a manager who has studied the characteristics of his men and has a thorough knowledge of their capacities and working conditions. Cer- tain of the old hands may have to be left in order to uphold tradition and to maintain a high quality of production. The younger men require particularly careful handling as with too drastic a reduction in their numbers they may no longer go straight; the thrusters would get in and prevent the best among the apprentice from making good. The re- organization will take time, but eventually only efficient workers will remain. Each will have room to work and the strong healthy youngsters will keep out the undesirables and finally make their way to the top. The foregoing deals only with the rain forest type which occurs in the mountainous regions. Land in the drier areas at lower elevations should not be neglected from the forestry point of view. Most landowners in such localities have areas where, owing to the steepness of the slopes or to the poor condition of the soil, they are unable to grow agricul- tural crops. These lands are often covered with a dense scrub, are browsed by stock, and eut over indiscriminately for firewood. They are generally in a neglected condition but under proper management they can be im- proved to yield timber and fuel. One of the commonest trees of the dry zone is white cedar (Tabebuia pallida Miers) which is one of the most valuable trees of the Windward Islands. It regenerates profusely and cleaning of the scrub in many cases would reveal numerous seedlings. If kept free from undergrowth and creepers, these seedlings would grow into fine straight trees. The bent and gnarled condi- tion of many white cedar trees is due to sup- pression and damage by undergrowth and creepers but if properly tended they would produce good clean timber. The best method 27 of treatment is to divide the area of scrub into ten equal parts and to deal with one part each year removing all useless growth and converting what is utilizable to charcoal. Trees of timber value such as white cedar and tanta- cayo (Albizzia caribbea) may be left an espacement of about 30 x 30 feet, giving about 50 trees to the acre. Periodic cleanings will have to be made to keep the trees free of creepers and at the end of 10 years the first area treated can be cut over for firewood leaving the timber species to reach maturity. Each area is cut over successively in this man- ner each year. The firewood coppices on a 10-year rotation and the timber species left to reach maturity on a rotation of 50 years. In areas where the natural growth is poor, or where it is desired to afforest open land, artificial planting is necessary. One of the most useful species for this purpose is teak (Tectona grandis L.) which thrives in the drier parts of these islands. It yields thin- nings from the fifth year which provide useful poles; the timber is unsurpassed for strength and durability. Teak plants are raised from seed in nurseries and when 1 year old the plants are lifted and the shoot and tap root are cut back leaving a stump about 9 inche3 long. The stumps are pit planted at an espace- ment of 6 x 6 feet in the month of June. For quick growing firewood plantations Cassia siamea Lamb. is recommended. The seeds of this tree are sown direct in the planta- tion in cultivated patches 3 feet in diameter and at an esnacement of 8 x 8 feet. When the seedlings are 6 inches high they are singled out leaving one at each spot. Cassia siamea grown on suitable sites can produce firewood and poles on a 10-year rotation. It coppices readily and once established requires no further sowing of seed. The accessible State forests in many of the islands are not sufficiently extensive io provide all requirements in timber, poles and firewood. Many private owners could utilize portions of their land, which are unsuited to agriculture or grazing, for the production of 28 timber and firewood. These woodlots would not only contribute indirectly by conserving the soil and affording shelter from wind but they would eventually yield a good cash return. The Windward Islands are entirely dependent on firewood as a source of fuel and stocks of suitable materials for burning to charcoal are becoming increasingly scarce near the large centers of consumption. Fuel is a commodity which will always be in demand and well -stocked plantations yielding 2,000 cubic feet per acre of stacked firewood in bil- lets 3 to 6 inches in diameter should prove profitable. High quality timbers such as white cedar, teak, and mahogany, can be grown with the firewood crop and, although the trees may take over 50 years to reach CARIBBEAN FORESTER maturity, it should be remembered that good stands of timber always enhance the value of the land. Summary The indirect benefits of forests are discus- sed; their effects on the climate and their im- portance in conserving the soil and in regulat- ing stream flow. An aliegorical description of tropical rain forest is given indicating the silvicultural treatment required to improve these forests and to increase their yield. Sug- gestions are made for the improvement of de- graded scrub lands and landowners are ad- vised how properly tended woodlots can bene- fit their lands indirectly and at the same time yield a good cash return. ; —-oOo-—- The Forestry Phase of the United States Technical Assistance Program in Chile JAY H. HARDEE, Forester {International Cooperation Administration Santiago, Chile The Agriculture and Natural Resources Division of the Technical Cooperation Pro- gram (Point IV) working with and through the Chilean Ministry of Agriculture, is paying particular attention to soil conservation. Foretry activities are part of this work. The Forestry Situation Natural Forests Chile is about 2,500 miles long and an average of a hundred miles wide. From 18 degrees south at the Peruvian border, it stretches to 56 degrees south at Tierra del Fuego. It has climates that vary from deserts in the north to 100 inches of rainfall on the coast in the south. Elevations vary from sea level to 22,000 feet. There is a wide variety of soil types. Most of the potentially comercial stands of timber occur in the area from 35°. latitude, south, to Tierra del Fuego. The important lumbering operations are now centered in the Temuco-Puerto Montt area in the coastal mountains and on the lower slopes of the Andes. The mountainous terrain and the high rainfall —the operating season lasts about 100 days— together with a dire shortage of roads, railroads and port facilities make production costs relatively high. This, and _ current market and foreign exchange conditions make perhaps three-fourth of the natural timber economically inaccessible. In 1944 a survey showed Chile to have 40 million acres, 22 percent of its land area, of forests and woodland. Fourteen million acres JANUARY - JUNE 1956 were classed as commercial forest land.t/ The report gave the volume as 65,000 million board feet, the growth as 1.1 percent annual- ly, and the depletion as 2 percent (1 percent by fire, 3 percent by cutting and .7 percent by other agents). Since that time the over- all volume figure has changed little, but a considerable portion of the accessible timber has been out —about 3,000 million bd. ft. For the past few years Chile has averaged an annual cut of about 250 million bd. ft. of which some 50 million have been exported. Plantations There are approximately 725,000 acres of tree plantations in Chile. The breakdown is about as follows: 550,000 acres of Monterey pine (Pinus radiata Don), 125,000 acres of blue gum (Eucalyptus globulus Labiil.), 15,000 acres of Lombardy poplar (Populus nigra L. var. italica), and 35,000 acres of other species.-’ The Monterey pine is marketed in the form of pulpwood and sawn lumber; the blue gum in the form of mine props, firewood and bridge timbers; and the Lombardy popla is used in match manufacture and as sawn lumber. The establishment of 550,000 acres of one single species in a period of about 20 years in a relatively small area, and with practically no market in view, is possibly without pre- cedent. The explanations are: (1) the very high profits realized by the owners of the small plantations cut between 1900 and 1950; (2) the high-pressure salesmanship of the several investment companies that bought 1/ In 1944 the U. S. Forest Service, in cooperation with the Chilean Development Cornoration, sent a mission to Chile head- ed by Dr. Irvine T. Haig to make an inventory of the forests and to evaluate the forest industrieg and their potentialities. The resulis of this excel'ent survey were published under the title, Forest Resources of Chile as a Basis for Industrial Ex- pansion. 2/ See ligt in the Appendix. 3/ Geod trees on good sites wil) grow to 8 inches dbh and 45 feet in height in 10 years; exceptional trees in fairly dense plantctions will average an inch in diameter and 7 feet in height each year for the first 8 to 10 years. The average acre of p'cntation under management can be expected to produce 75 cords of nu'nwood in 25 vears or 48 M bd. ft. at 30 years. Higher yields can he exnected on the better sitec. The Haig report (see foot note number 1) cites a 36 year old planta- tion with a volume of 74M hd.ft. per acre with an average annual increment of 374 cu. ft. or 2,044 bd. ft.; the report mentions another plantation with very similar yields. _There are cases of claimed volumes of over 80 M bd. ft. per acre. 28 cheap land, planted, and sold stock or indivi- dual lots of one hectare of trees; (3) relati- vely low cost of land and plantation establish- ment; and (4) the extraordinary growth rate of Monterey pine in Chile®’. New Zealand has about the same acreage of Monterey pine; but, more of their plantations have been thin- ned and pruned, they have a market in near- by Australia and their transportation and port facilities are able to handle their production. It is estimated that within the next 10 years, Chile will have sufficient raw material in her Monterey pine plantations to produce some 1,000 million bd. ft. of lumber annually (four times the current production of all species) and support six to eight pulp and paper mills with an annual capacity of 100,000 tons each. The recent annual production of pine has been about 25 million bd. ft. of which 8 million were exported. If Chile could triple her internal market she would still have to export about 950 million feet, which is 118 times last year’s exports. Two complemen- tary pulp and paper mills with a combined yearly capacity of 100 thousand tons are under construction but will not be in full production until 2 years from now. It would require four or five mills of this size to absorb the wood produced by the necessary thinnings and the stagnated plantations that will have to be clear cut for wood within the next 5 to 6 years. During the last 3 years the people working with these plantations and in the forest product industries have come to recognize the problem and its magnitude. They have re- solved to do everything possible to make the best of the situation under the limitations of capital and transportation facilities. The Early Pregram Efforts during the first year of the program were directed mainly to a study of the country’s forestry problems with particular emphasis on tree planting and its role in soil conservation. The pine plantations and their future were obviously vital; most of the 450,000 acres established up to that time were planted on badly eroded lands that were fit 30 for nothing else. Their silvicultural manage- ment, logging, milling, and potential markets were intensively studied. There are approxi- mately 714 million acres of such land still to be planted to trees in Chile. Whether the existing plantations earned a profit for the investors would largely determine the future reforestation program. During the first year the work was similar to that of a country extension forester but spread over a much larger area. Many farms were visited and recommendations made on plantations, their establishment and manage- ment, and on the management of the cutover natural stands as wood lots. Assistance was given to a government agency in an effort to trade pine lumber for hospital supplies; in- formation was supplied to fruit growers on disease and storage problems. Bulletins were prepared on nursery procedures for the pro- duction of plants of Douglas fir (Pseudotsuga menzestt (Mirb. Franco) and Nepal cypres (Cupressus torulosa Don.) and seeds were supplied to interested landowners. This was the first assistance given in the effort to con- vince them of the need to plant other species. It was recommended that an experimental species-introduction project be undertaken for the following reasons: 1. The inminent supersaturation of the pine market. 2. The need for planting species that pro- duce quality lumber with strength and durability. 3. The susceptibility of these pine planta- tions to insect and disease outbreaks. CARIBBEAN FORESTER 4. The belief that the future of the forest industries lies mainly in plantations of exotic fast-growing species near the communication arteries and population concentrations in central Chile. The Species Introduction Project A species-introduction project was carried out by the cooperative “servicio” of the agri- cultural mission and the Ministry of Agricui- ture. Seed was sown in August of 1952 in the American Methodist Mission farm near Angol. They operate a fruit and ornamental nursery and offered to cooperate with the “servicio” in the project. A total 126,000 plants of 20 species were produced and were planted in 17 provinces throughout the tree zone of Chile. The plots were 1% acre in size and were in most cases planted with a 2 x 2 meter spacing on sites typical of the land available for forest planting in the area. The objective was 15 plots of each species. The plants were produced in a newly es- tablished “servicio” nursery near the city of Chillan during the second and third years. (See Figure 1). Plants of 57 species have been produced and planted in sufficient quantities to permit a good trial of each species. Sur- vival has been only fair due primarily to un- usually adverse weather, shipping delays, and lack of protection from animals. The ap- pendix lists the species that have been succes- fully established and show the most promise at the present time. At least ten of the species tried appear suitable for planting in Chile. However, if only three or four prove to be as adaptable as Monterey pine and blue gum then the project will have been a success. JANUARY - JUNE 1956 Fig. 1—A view of the nursery at the end of the first season. The Three Province Plan It was decided by the Mission and several Ministries of the Chilean government to con- centrate a large part of the technical coopera- tion work in the three provinces of Maule, Nuble, and Concepcion, where agriculture has not kept pace with the industrial expansion of the city of Concepcién. The forestry work within this area consists of the establishment of a central nursery, demonstration reforesta- tion projects on badly-eroded lands, the in- troduction of new species, dune control, and extension work in planting, pruning, thinning, and management. Most of this activity is car- ried out as a forestry phase of the soil conser- vation program; some work is done in collabo- ration with the forestry department of the Ministry of Lands and Colonization. It is estimated that 40 percent of the three provinces of the development area, called locally the Plan Chilldn, will be classified as forest lands. The total area is 6.1 million acres with 350,000 acres already in planta- tions and 1.9 millions acres that should be planted. Only a small percentage of the land is covered with virgin forest or any second- growth of consequence. The area that should be planted is very badly eroded. Some of it is so bad that it is doubtful if successful plan- tations can be established; most of it is no good for any other use. Pian Chillan Nursery When it was realized that nearly one- third of the area included in the Plan needed to be reforested, the establishment of a nurse- ry to furnish the plants was given priority. All the work of site preparation and seeding was done by hand or with animals and the first seeds were sown on September 17, 1953. The production was 3.5 million plants during the 1953-54 season and 6 million in 1954-55. 32 At the beginning of the third seeding season the nursery had two permanent build- ings under construction. One building will serve as an office, germination room, labora- tory, and refrigeration room for storage and stratification; the other will be a residence for the nursery administrator. Other buildings are being planned. A deep well has been dril- led and a sprinkler irrigation system has been installed. The nursery has now been allotted 126 acres of land; the soil is being leveled and improved and interior graveled roads are under construction. Most of the tools and tractor equipment needed are on hand. CARIBBEAN FORESTER Except for the fact that there is less mecha- nization, the operations of this nursery are much like those in the United States. It also differs in that an unusual number of species, are produced. During the 1945-55 season, 6 million plants of 64 species were raised and sold at cost. The production goal for the 1955-56 season was increased to 12 million plants. The ultimate goal is to produce 25 million plants annually (about 17 million pine are now being planted yearly in Chile) to substitute better species for the Montery pine and to increase the acreage planted each year in the area (See Figure 2). The nursery also supplies plants to three other provinces. Fig. 2.—A demostration of tree planting; the planting bar was introduced by ICA and is well liked by owners as well as the workers. It has doubled number of trees planted per day. The large number and variety of species produced creates a great amount of work but is justifiable because of the research and train- ing objectives of the project. A list of the species produced on a large scale is in the ap- pendix. Watershed Protection Project The Mission is also cooperating with the Forestry Department of the Ministry of Lands and Colonization in the operation of two projects in the Plan Chillan: (1) the refores- tion of the Andalien River watershed, and JANUARY - JUNE 1956 (2) the stabilization of the coastal sand dune3 at Chanco and Reloca. These are long range projects that will require severa! years and considerable money to carry them to comple- tion. The objective is to set up demonstra- tional “pilot” projects, help organize them on a sound basis, train the Chileans in the proper methods by working with them unt:] the projects are progressing normally, and then turn them over to the Forestry Department. The Andalien river flows through the city of Concepcion and often reaches flood stage in the winter. The river drains a section of the coastal range of mountains that has some of the worst erosion in Chile. Of the 175,000 acres in this watershed about one third has been planted to Monterey pine, one third is agricultural and grazing land, and the other third badly needs reforestation. The primary problem encountered in the watershed im- provement program is socio-economic. Most of the land is owned in small submarginal units by farmers who, because they have in- sufficient land, continue to further impove- rish the land and themselves by planting wheat on 20-45 percent slopes. If the re- forestation and pasture establishment reme- dial program is to be carried out, these small farmers will need financial assistance from the government to buy cattle and live until the planted trees can be harvested. One practical forester has worked for 8 months in a “pilot”? watershed of 33,000 acres. A complete census has been taken and some 730,000 trees, sold to the farmers at cost, were planted in the area. The technician gave assistance by distributing the plants and tools and by training the planting crews on the p iarms. Plans are now being made to concentrate several of the conservation projects of the Plan in the pilot area. These projects will include the construction of terraces and farm ponds, the introduction of contour farming methods, general health and sanitation im- provement practices, etc. It is hoped that funds and personnel will be made available to 33 expand this program from the pilot area to cover the whole watershed. Chanco Sand Dune Project There are several coastal sand dune areas in Chile where valuable agricultural land is being covered by sand dunes. An area at Chanco-Reloca is included in the Plan Chillan. Approximately 15,000 acres of some of the richest farm land in Chile have been covered by sand and an equal area is threatened. The area is almost i00 percent agricultural and once supplied a surplus of agricultural prod- ucts for shipment. New hardly self-sufficient, the community will undoubtedly shrink to practically nothing if the sand dunes are not stopped. Some excellent work was done near Chanco 50 years ago and the towr was temporarily saved. Since that time, however, efforts and funds have been sporadic and part of the de- fense established has been lost. There are about 15,000 acres in the whole dune area of which some 1,900 are in tree plantations from 40-50 years old. This project has been in operation 15 months. The existing planta- tions have been improved, grazing has been practically eliminated by fencing, and about 125 acres of trees have been planted on areas protected by brush fences. A 71!5-acre grass nursery has been established with accessions of European beachgrass (Ammophila arenaria (L.) Link) from France, Oregon, England, and Chile, and American beach grass (A. breviligulata Fern.) from Oregon. Small-scale experimental work is being carried out on the dunes. The nursery should produce enough grass within 2 years to begin full-scale plant- ing for a litoral dune. The experience of the U. S. Soil Conservation Service in the Pacific Northwest has served as a guide for this project. The plans are to generally follow the accepted procedures in dune control work. It is believed, however, that experience will prove that the intermediate stage of shrubs can be eliminated and that trees can follow the grass. These sands are of volcanic origin and according to soils experts become o4 somewhat fertile with the addition of a small amount of organic matter. This is certainly borne out by the good growth of several species of trees on these sands. The species that are growing well on stabilized dunes at Chanco are listed in the appendix. There is a practical forester and a practical agriculturist working on this project under the supervision of a graduate agronomist. The project will serve as a model for other dune areas in Chile. Personnei Training The nursery has given thorough training to two Chilean graduate agronomists!/, four Chilean practical agronomists, and one Uru- guayan practical agronomist on scholarchip to the nursery. In addition it has given same training to several people for short periods. Many groups of students of agricultural schools and universities have been conducted through the nursery. In the Lands and Colonization projects three practical foresters and a graduate agro- nomist have received training in forestry, ero- sion control, and dune control. Two short courses emphasizing practical work in planting, thinning, and pruning have been held to date: one for 15 foremen working in plantations and one for 25 agronomists of the Plan Chillan. As texts for the courses and to fill the needs of landowners, bulletins on species selection, planting, thinning, and prun- ing were prepared. If any appreciable amount of Monterey pine lumber is to be sold in the world market it will have to come from plantations that were properly pruned and thinned in their youth. A forestry extension program is being planned to give training in plantation manage- ment to landowners and their employees. This will eventually cover all the phases of forestry normally covered by forestry extension in the United States. 4/ The term agronomist is apolied to graduates in general agri- culture, CARIBBEAN FORESTER In the scholarship program offered by the International Cooperation Administration, one Chilean agronomist has just recently com- pleted a year at a forest school in the southera United States. The graduate agronomist from the nursery and the one from the Forestry Department have left for the States for a year’s training in other forest schools. The men picked for these scholarships are men who have proven their worth while working in the projects. Summary The Point Four Forestry Program in Chile, with one American forester and an average staif of one graduate agronomist and four practical technicians, has accomplished much in the 3!4 years since its inception. 1. The establishment of a permanent nur- sery with a potential production capa- city of 25 million seedlings is almost completed. Three and one-half million plants were produced during the first year and 6 million the second. A goal of 12 million was set for the third year. This nursery carried out research on the production of seedlings of both indigenuos and exotic species under local conditions. 2. An experimental program for the in- troduction of new species of trees for erosion control and timber production has been undertaken. Sufficient seed- lings for a good trial of 57 species have been planted in half-acre plots on sites typical of those available for tree plant- ing. 3. A project to foment reforestation and erosion control by giving technical as- sistance to landowners in an important watershed haz been initiated. A com- plete study of a pilot area was complet- ed and, largely as a result of the project, about 600 acres of trees have been planted in the test area the first year. Plans are being made to offer many forms of agricultural assistance in the area. JANUARY - JUNE 1956 4, A project for the stabilization of coastal sand dunes has been instituted. The objective is to introduce plants and the latest technology for dune control, to organize the project, and to train Chilean technicians so that they may continue the work alone. 5. Three graduate agronomists have been trained in nursery management, ero- sion control, general forestry and dune control. One Uruguayan practical agro- nomist has had a year’s scholarship to the nursery and has received thorough training in nursery work. Four Chilean practical agronomists have been trained in nursery work and three practical foresters have received train- ing in nursery work, erosion and dune control, and general forestry. Fifteen plantation managers and woods fore- men and 25 graduate agronomists at- tended a short course on planting, pruning, and thinning which emphasiz- ed practical work. 6. One agronomist has completed a scho- larship of a year’s study in forestry in the United States and two more are studying there now. 7. A type of forest extension service has been offered sporadically to land- owners.. Six bulletins on nursery pro- cedures, species selection, pruning, thin- ning, and planting have been prepared and distributed. oo (A Conclusions The experience of the writer in Chile, where every species recommended at the present by foresters for large-scale planting is an exotic, has caused him to make an _ observation that he would like to present here. It could very well happen that after valuable time and resources have been spent developing hybrids and selecting strains of native species, that exotics will be found that will produce more and better wood than the improved indige- nous species. How can we be sure trat we are working with the right trees? It seems that the approach should be to try all the species in the world that might thrive in a particular area in order to find the trees best suited for it —then begin hibridizing and selecting. At this stage, perhaps the greatest pos- sibilities for advancement in forestry lie in the selection of the best species for given sites. There are 1.4 million acres of Monterey pine planted in Chile, South Africa, New Zealand and Australia. In Europe exotics make up and integral part of planting and are becoming increasingly important. The variety and quantity of fruits, vegetables and meat avail- able would be muck less if the agronomists, horticulturists and animal husbandrymen had limited themselves to native species. A large experimental program with exotics is needed to find the best species for future planting in any country. Appendix Species other than Monterey pine, bluegum, and lombardy poplar that are planted in Chile, in order of area planted: Pinus pinaster Aiton. Cupressus macrocarpa Hartw. Acacia melonoxylon R. Br. Robinia pseudoacacia L. Acacia dealbata Link Eucalyptus spp. Pinus elliottii Engelm. Cupressus torulosa Don C. arizonica Greene Pseudotsuga taxifolia (Porite) Brit. CARIBBEAN FORESTER Species successfully established and doirg well in the species-introduction project to date: Catalpa speciosa Warder Eucalyptus melliodora A. Cunn. E. camaldulensis Dehn. Fraxinus pennsylvanica Marsh var.lanceolata (Bork.) Sarg. Gleditsia triacanthos L. Juniperus virginiana L. Morus alba L. var. tartarica Pinus attenuata Lemm. P. halepensis Mill. P. jeffreyi A. Murray P. longifolia Roxb. P. nigra Arnold P. taeda L. Populus Mussolini hybrid Ulmus pumilla L. Species observed growing well as individuals or in small groups that show possibilities as timber trees: Araucaria brasiliana A. Rich. Castanea spp. Casuarina cunninghamiana Miq. C. equisetifolia Forst. Cedrus deodora Loudo.. Ceratonia siliqua L. Chamaecyparis lawsoniana Parl. Cryptomeria japonica D. Don Larix leptolepsis Murr. Liquidamber styraciflua L. Liriodendron tulipifera L. Pinus canariensis C. Smith. P. sabiniana Douglas P. patula Schl. & Cham. P. sylvestris L. Quercus suber L. Thuja plicata D. Don All of these species have been tried in the species-introduction project but not enough plants were successfully field-planted to give them a fair test; some will be repeated. Species produced on large scale in the Chillan Nursery: Cupressus arizonica Greene C. torulosa Don Eucalyptus globulus Labill. Juglans nigra L. Pinus elliottii Engelm. P. pinaster Aiton P. ponderosa Douglas P. radiata D. Don Pseudotsuga taxifolia (Poiret) Brit. var. viridis Robinia pseudoacacia L. Sequoia sempervirens Endl. Tree species thriving on the stabilized sand dunes at Chanco: Acacia armata R. Br. A. dealbata Link. A. melanoxylon R. Br. Cupressus macrocarpa Hartw. C. torulosa Don Eucalyptus globulus Labill. Eucalyptus spp. Pinus pinaster Aiton P. pinea L. P. radiata D. Don Robinia pseudoacacia L. JANUARY - JUNE 1956 Od Procedimientos para Pequenos Viveros Forestales en Chile’ JAY H. HARDEE Instituto de Asuntos Interamericanos Chile Introduccion El presente articulo ofrece recomendacio- nes de tipo general sobre los procedimientos iturndamentales para la crianza de plantas fo- restales, especialmente de coniferas. La ma- yoria de los pequefios viveros creados en el pais a modo de experimentacion puede decirse que ha fracasado y no se ha logrado de ellos el éxito econdédmico esperado. En la actuali- dad sdlo hay ocho a diez viveros en todo el pais que producen especies ex6ticas, fuera del pino insigne (Pinus radiata D. Don), pino maritimo (Pinus pinaster Aiton), y el gomero azul (Eucalyptus globulus Labill), y que ob- tienen buen rerdimiento econdédmico. Las tres especies mencionadas son muy rusticas, rela- tivamente faciles de criar y las semillas obte- nibles a bajo precio. Por el contrario otras especies con propiedades distintas como el pi- no Oregén (Pseudotsuga taxifolia (Poiret) Brit. var. viridis) son de dificil produccién pues requieren tratamientos y equipos espe- ciales. La semilla ademas de costosa, es difi- cil de obtener. En la mayoria de los casos debe insistirse en la poca conveniencia de establecer viveros de tipo casero en los fundos. Un vivero re- quiere: buenos suelos, sistemas eficientes de regadio, inversiones considerables en equipos y materiales y ademas la atencién perma- nente de un técnico con conocimientos amplios en la materia. Los viveros fiscales y algunos particulares venden las plantas a mas bajo precio que a lo que podrian ser producidas en los viveros particulares. Los pocos caso3 que justifica- rian la existencia de sus propios viveros, ce- 1/ El articuto titulado “The forestry phase of the United Statec Technical Assistance Program in Chile” nublicado en Ia pa- gina 28 de este mismo nUmero describe en detalle e! programa forestal chileno. rian aquellos cuyos terrenos estan situados en lugares inaccesibles a las vias de transporte en invierno o los que plantan una superficie mayor a unas 150 a 200 hectareas por ano. Seleccion del Sitio y Programa de Fertilidad de los Suelos En la eleccién del sitio mas adecuado para la ubicaciOn del vivero, es necesario conside- rar dos aspectos de mucha importancia: el suelo y el riego. El suelo ideal es un “miga- jon” arenoso, fértil, profundo y bien drenado. El pH debe fluctuar entre 5.5 y 7. Los “tru- maos” no arcillosos son muy buenos. Los sue- los arcillosos no se prestan. El sitio debe te- ner una fuente cercana de agua limpia y li- bre de semilla de malezas. La creencia de que un Arbol que sera plan- tado en sitios pobres, secos 0 en arenales, debe ser criado en un sitio similar, es errénea; las plantas deben ser criadas en vivero de condi- ciones 6ptimas, de modo que la planta llegue al sitio definitivo con todo el vigor y fuerza posible. Otro aspectc importante que debe ser con- siderado es la mano de obra, es decir, el nt- mero de obreros necesarios para una produc- cion determinada. Una tasa que puede ser- vir de pauta bajo las condiciones que se des- criben en este trabajo es de cuatro obreros vara una produccion de medio millén de plan- tas. E] sitio de ubicacion debe ser de facil ac- ceso y mas 0 menos a nivel. No debe estar sombreado por arboles ni rodeado por mato- rrales y se debe disponer de cercas adecuadas para impedir el acceso de ratones y conejos. Programa de Fertilidad del Suelo Al elegir un sitio, que ademas de reunir otras condiciones, sea fértil, seguramente no 38 se tendra problemas serios en mantener la fer- tilidad. Si por el contrario, el vivero se ha establecido en un suelo agotado, erosionado o pobre es preferible cambiarlo de lugar, pues ademas de las pérdidas consiguientes de re- cursos para mejorar el suelo, dificilmente el terreno pobre podra convertirse en terreno fértil. La mayoria de los suelos aptos para viveros en Chile, los “trumaos” u otros “mi- gajones’, son faciles de manejar en lo que se refiere a fertilidad. Una produccién de 500 plantas forestales por metro cuadrado, que debe considerarse normal, agota los elementos del suelo mucho mas que un cultivo agricola, siendo por lo tan- to mucho mayor la necesidad de emplear abo- nos. En este sentido debe procederse con cui- dado pues el exceso de elementos quimicos es mas peligroso que la falta de ellos. El exceso de nitr6geno, por ejemplo, puede hacer que la planta se seque o crezca demasiado. Una manera prudente de proceder, es aplicando la misma cantidad de fertilizante que se reco- mienda para siembras agricolas. Si la expe- riencia indica que el suelo esta en un proceso avanzado de agotamiento, se puede aplicar una dosis una y media veces mayor que la recomendada. Con los afios se puede ajustar las aplicaciones segin se vaya teniendo expe- riencia. Si las plantas no se desarrollan bien por falta o exceso de elementos, es preferible consultar con un experto en suelos. Dentro de los elementos fertilizantes, los de mayor importancia son: el nitrdgeno, el fésforo y el potasio. El salitre potasico chile- no es una buena fuente de nitrogeno y potasio. Es posible que el suelo necesite cal, pero no hay que aplicarla sin establecer la necesi- dad, pues una aplicacién excesiva puede cau- sar deficiencias en otros elementos, ademas de tavorecer el ‘“damping-off”. En algunas zonas de Chile, se ha exagerado el uso de cal. En todo caso, cuando no se conozca bien el suelo, es preferible hacer las consultas de ri- gor a un técnico. También son importantes los elementos menores, tales como boro, cobre, manganeso, CARIBBEAN FORESTER zinc, etc. En algunos suelos chilenos la falta de elementos menores presenta problemas. La aplicacién de abonos debe hacerse 2 6 3 semanas antes de sembrar las semillas fo- restales. En el caso de hacerse la aplicacién en la temporada de otono, las fuertes lluvias de invierno causarian la lixiviacion de los abo- nos con una consiguiente pérdida. Siempre existe un cierto peligro al aplicar abonos con- centrados poco antes de la siembra; pero en las zonas lluviosas de Chile es necesario ha- cerlo. Hay que asegurarse que los abonos se mezclen muy bien con la tierra, para evitar danios a las plantas. Es imprescindible la rotacién de los sue- los para evitar problemas con “damping-off’’, algunas especies de insectos y también para evitar, en parte, el agotamiento y cambios en la estructura del suelo. Sin embargo, y a pe- sar de esto, la rotacién por si sola los evita en parte pero no basta para solucionar estos problemas. Con respecto a este punto, se re- comienda una rotaciOn de 3 afios; 1 ano en arbolitos, 1 afio en abono verde o siembra de chacareria, y el tercero en una siembra que exija un cultivo limpio, como seria porotos o maiz, lo cual tendria la ventaja de reducir la cantidad de malezas en los arbolitos al afio siguiente. Hay técnicos en suelos que dudan que los abonos verdes sean econdmicos y al respecto agregan que la cantidad de materia organica producida, no compensa el costo de producir- los. Tal vez sea mas econdmico sembrar una especie cosechable que sembrar abono verde; en todo caso existiria materia orgadnica que se incorporaria al suelo. El cultivo de arve- jas y porotos es bueno pues éstos afaden ni- tr6geno al suelo. La erosién laminar, comtin en los viveros del pais, debe ser corregida por trabajos de nivelacién o desagiies. Todos los trabajos tendientes a mejorar los suelos resultaran per- didos, si existe erosién, aun cuando ésta sea ligera. JANUARY - JUNE 1956 Tratamientos de la Semilla En General Las semillas forestales, al igual que !a3 de siembras agricolas, deben ser bien selecciona- das, frescas y de buena procedencia. Pueden ser adquiridas en semillerias comerciales, pero a menudo estas semillas estan mezcladas con otras especies, no por mala intencidn del co- merciante, sino por ignorancia de los recolec- tores, quienes muchas veces no saben distin- guir las semillas de distintas especies. Para aseg. se de que las semillas sean frescas, sin la y procedentes de buenos Arboles, sere ziso recolectar las semillas 0 comprar- las uellas personas que cosechan sus pro- pie nillas. Si se trata de semillas impor- tar sera conveniente consultar a las perso- né 2 han tenido experiencia en la importa- cl > semillas forestales. _la mayoria de las especies y en particu- it atandose de las coniferas, las semillas if mn guardarse a una temperatura entre 1 ] srados centigrados y en envases herméti- mte sellados hasta un periodo de 3 6 4 , sin sufrir grandemente en su capacidad uinativa. Los lotes pequefios de semillas no justifican almacenarse pueden guar- se en frigorificos, en frascos o “chuicos” ‘ados y en lugares frescos y secos, pues las ullas se deterioran rapidamente cuando es- . expuestas al calor y la humedad. Una nera practica de hacerlo tratandose de lo- ; pequefios es sometiéndolas a una tempe- tura no superior a 40°C, hasta que estén en secas, revolviéndolas constantemente; ac- » seguido se ponen en frascos o latas y se se- in herméticamente, colocandolas entonces en gares frescos. Es imprescindible conocer el porcentaje de apacidad germinativa con el objeto de calcu- zar el numero de semillas que hay que sem- brar en un metro-hilera en las platabandas. Si se siembra demasiado tupido se pierde el aprovechamiento maximo de las semillas; si se siembra muy ralo, se pierde parte del costo de preparaciéa del suelo del riego, cultivos y también, calidad en las plantas. Para produ- cir plantas con buenas caracteristicas, es pre- ciso mantener en las platabandas densidades exactas. La inspeccién fisica de las semillas, da una idea de lo que se puede esperar en cuan- to a germinaciOon, pero es solo una indicacion. La germinaciOn es generalmente mucho me- nos que el porcentaje de semillas buenas dado por la inspecci6én fisica. Para realizar la ins- peccion fisica se saca una muestra represen- tativa de todo el lote, tomando unas pocas se- millas de todas las zonas de la bolsa y mez- clandolas con otras muestras de otras bolsas; de esta mezcla final se sacan las semillas que serdn inspeccionadas. El ntimero de semillas que se inspecciona depende del ntimero de ki- los y de la cantidad de semillas por kilo. Se corta la semilla transversalmente, usando una hoja de afeitar, y se observa el estado del en- dospermo y el embrion. Si estas partes estan arrugadas, amarillas, quebradas, o atacadas por insectos la semilla no germinara. * Si‘ se trata de una especie cuya semilla es pequena, sera necesario usar una lupa. La prueba de germinacién se hace 30-45 dias antes de la fecha de siembra, o sea en los meses de julic y agosto. La temperatura al aire libre no es suficiente para probar la germinacién y es preciso hacer las pruebas en salas o camaras con calefaccién. La tem- peratura debe mantenercse a 20°C en la no- che y 30°C en el dia. Se puede hacer prue- bas en piezas con temperaturas de 22 - 23°C en el dia, pero no se puede estar seguro que la prueba ha demostrado realmente la capa- cidad de la semilla para germinar; sin embar- go una prueba bajo estas condiciones es me- jor que ninguna. Se pueden improvisar camaras chicas con capacidades de un metro cubico, calentadas por estufas o ampolletas eléctricas con un ter- mometro colocado al mismo nivel de las se- millas. Son varios los medios usados para pruebas de germinaciOn: papel secante para pruebas pequefias de poca importancia, y arena del rio AO libre de materia orgdnica para pruebas de gran tamano, son los que proponemos en el presen- te boletin; ambos son baratos, faciles de con- seguir y dan buenos resultados. El papel de- be ser de buena calidad, mientras mas grueso mejor. Las arenas que se encuentran en los rios y que han sido bien lavadas por las aguas son buenas y no es necesario esterilizarlas, siempre que no contengan materia organica ni arcilla. Las semillas se colocan uniformemente dis- tribuidas en el medio usado a una distancia igual al didmetro de la semilla como distancia minima. Se debe mantener el medio himedo pero nunca sobre-saturado; si e3 arena, uno o dos riegos ligeros por dia aplicados con una rociadora de mano es suficiente (similar a la usada para combatir insectos). El rocio debe ser muy fino para no producir movimiento de la arena en su superficie. La germinacion puede empezar entre los 5 y 10 dias segtin sea la especie; generalmen- te comienza entre 10 y 12 dias y termina en 30. Los lotes de semillas de la misma especie pueden variar mucho en el periodo pregermi- nativo y en el tiempo necesario para la prueba de germinacion, pero generalmente 30-40 dias es suficiente. Si parte de la semilla ha ger- minado bien a una fecha determinada y el resto no germina después de 6-8 dias puede considerarse la prueba terminada. Durante la prueba se sacan la3 semillas germinadas cada dia o cada dos dias anotando la cantidad. Se considera germinada una se- milla cuando le ha salido la raiz y las hojas primarias en forma normal. A veces, a pesar de todo el cuidado, los hongos atacan las se- millas antes que germinen bien; en este caso se cuenta la semilla como germinada si ha mostrado los principios de germinacion en for- ma natural. Tratamientos Especiales En algunas especies es preciso tratar las semillas antes de sembrarlas para lograr una germinacion rapida y mas alta. dos de dichos tratamientos varian en cada lote Los resulta- CARIBBEAN FORESTER de semilla de la misma especie de tal manera que sera necesario hacer pruebas de germina- cidn con semillas tratadas y sin tratar para poder determinar si conviene hacerlo. Los tratamientos mas frecuentemente usa- dos son: Estratificacion Kl objeto de este proceso es reproducir en todas sus formas lo que le ocurre a las se- millas en los bosques de climas templados. En otono caen y estan expuestas al frio; y en in- vierno a la humedad, hasta que comienza la época de calor en primavera, que la hace ger- minar. Generalmente las semillas de germi- naciOn mas alta son las de coniferas, y cuan- do se tratan por este método su germinacién es ademas muy uniforme y rapida. Hay es- pecies donde la estratificacién es absoluta- mente necesaria para conseguir una germina- cidn satisfactoria. Una germinacion alta es ventajosa y ademas una germinaci6n rapida permite a las plantas un periodo mas largo para desarrollarse. Si la germinacién ademas de ser rapida es uniforme, las plantas tendran el mismo tamafio y las mismas oportunidades de competir entre si. En el caso de que se desee saber si es 0 no conveniente estratificar las semillas, sera ne- cesario hacer pruebas de germinacién de se- millas estratificadas y sin estratificar. Estas pruebas deben comenzarse unos 100 dias an- tes de la fecha de siembra, para dar unos 30 dias para la estratificacién de la muestra; 30 dias para la prueba de germinacion, y 40 dias para efectuar la estratificacién en gran escala, siempre que las pruebas hayan indicado su conveniencia. La estratificaci6n se hace entre 30-60 dias antes de la fecha de la siembra, siendo lo mas recomendable unos 45 dias para la mayoria de las especies. Aunque las semillas estratificadas germi- nan un poco mas (4-5 por ciento) que las sin tratar, a veces es conveniente estratificar para conseguir una germinacién mas rapida y uniforme. La experiencia obtenida con la JANUARY - JUNE 1956 especie es el criterio que se usara al tomur la decision. El procedimiento de estratificar las semi- llas es el siguiente: se toma un cajén o ban- deja de lata o madera dentro del cual se coluca una capa de arena lavada de 10 cms.; se pone una cantidad suficiente de semillas en una bol- sa (de género muy permeable) para formar una capa de semillas de 2 a 3 cms. de espe- sor; después se coloca otra capa de arena de 10 cms. sobre las semillas; se riega ccpiosa- mente la arena y semillas, debiendo el envase tener agujeros en el fondo para dejar salir el exceso de agua. Debe mantenerse muy himedo durante el periodo. Una vez que se hayan preparado los envases se colocan en el frigo- rifiico manteniéndose durante el proceso una temperatura de 3 a 4°C; si se deja subir la temperatura mas alla de 6°C, se corre el ries- go de que se inicie el proceso de germinacién perdiéndose con esto las semillas. Se ha teni- do éxito en algunos casos estratificando se- milla al aire libre y sembrando anticipadamen- te. Esto es muy arriesgado y no se reco- mienda. Remojo En el caso de que la estratificaci6n sea im- posible, se puede acelerar la germinacién de muchas especies remojandolas en agua por periodos desde 24 horas hasta 7 6 10 dias se- gun sea la especie (el volumen de agua ha de ser 6 a 7 veces mayor que el de las semi- llas). En el caso de pino Oregon el periods mas indicado es de 5 a7 dias. Se recomienda cambiar el agua diariamente con el objeto de impedir posibles fermentaciones. La tempera- tura puede fluctuar siempre que no exceda de 20°C ni sea inferior a 5°C. En casi todas las especies se puede adelantar y a veces aumen- tar la serminaci6n remojando las semillas 24 horas. No se debe sobrepasar este periodo a menos que se tenga experiencia anterior con la especie. Conviene observar las semillas du- rante el remojo para asegurarse que no fer- mentan y ademas que las cascaras no s2 ablan- den demasiado. Las semillas mojadas son mas dificiles de sembrar por lo cual se reco- 4] mienda ponerlas previamente a secar 1 6 2 horas antes de la siembra. Una vez que se ha remojado no conviene dejar secar la pai'te interior de la semilla. Coccion Las semillas de muchas especies legum:- nosas germinan mas rapida y uniformemente si han sido hervidas desde 30 segundos hasta 5 minutos en un volumen de agua seis a siete veces al de las semilles secas. Si no se tienen datos precisos al respecto, convendra efectuar ensayos con distintos periodos de tiempo. El agua debe estar hir- viendo al sumergir las semillas las cuales se retiran rapidamente al transcurso del tiempo indicado. Una vez que las semillas han sido hervidas no conviene dejarlas secar ni tampo- co esperar demasiado antes de sembrarlas. Ademas de los tres tratamientos arriba ci- tados, se emplea también la escarificacién, tratamientos con acido y tratamientos con otros productos quimicos, pero su uso no se recomienda para viveros pequefios. Como Calcular la Cantidad de Semilla a Regar Generalmente el porcentaje de germina- cidn en el vivero es de 50 a 60 por ciento de la germinaci6n en el labsratorio; ésta depen- de de la preparaci6n y Gei tipo de suels, el tiempo y otros factores. Bajo condiciones fa- vorables en buenos viveros, se puede esperar que un 30 a 66 por ciento de las semillas via- bles sembradas produzcan plantas aprovecha- bles para la plantacién en el campo. Es- te porcentaje se llama porcentaje de arbo- les. Las semillas que germinan en el vivero tienen que sufrir pérdidas causadas por hon- gos, insectos, pajaros, cultivos y ademas por la competencia de las otras piantas. Supo- riendo que las semillas de pino germinaron un 80 por ciento en el laboratorio; la germi- nacion en el vivero es mas 0 menos 70 por ciento de la germinacién en el laboratorio, 9 sea 56 por ciento de las semillas sembradas;: los arbolitos aprovechables, o el porcentaje de arboles sera alrededor de la mitad del 42 porcentaje del laboratorio 50 por ciento, 0 sea unas 40 plantas por cada 80 semillas viables. En las especies de hoja ancha (no coniferas), se puede estimar que el porcentaje de arboles sera entre 10 y 30 por ciento del porcentaje de germinacion del laboratorio. La densidad optima de plantas sembradas en hileras de 15 cms. de separaci6n es 80 plan- tas por metro de hilera en el caso de una slembra de pino maritimo insigne o caribe. Si en el laboratorio las semillas germinaron 74 por ciento, como la germinacion en el vivero se considera 70 por ciento del porcentaj2 an- terior, la germinacion en el vivero sera de 52 semillas de cada 100. Ahora bien, como la cantidad deseada es de 80 plantas por metro de hilera, y solo el 52 por ciento germinan en el vivero, resulta que es necesario sembrar 154 semillas por metro-hilera para obtener la densidad deseada que es 80. Se considera, ademas, que en promedio la mitad del porcen- taje que germina en el laboratorio, seran plan- tas aprovechables; para nuestro caso son 37 plantas por cien semillas sembradas; en el caso de sembrar 154 semillas, resultaran plantas aprovechables 57, por metro de hilera. Ger- minan 80 por metro, pero se puede esperar la pérdida de 23 plantas por metro durante la temporada, y en la clasificacién de las plan- tas cuando se las despacha. Con el objeto de evitar siembras muy tu- pidas, o en el caso contrario, muy ralas es necesario hacer el calculo arriba citado antes de sembrar y por cada lote de semilla. A fines de febrero se puede calcular la pro- duccién contando muestras en todas las par- tes del vivero y reduciendo las cifras en un 20 por ciento por las pérdidas que suelen ocu- rrir desde febrero y ademas por aquellas plan- tas que seran eliminadas en la clasificacion. Labranza y Construccion de Tablones La tierra se ara profundamente, se rastri- lla y se nivela dejandola bien suelta y libre de raices, ramitas y pastos. Si se tratara de un sitio que no hubiere tenido cultivos el ano anterior, es necesario ararlo y rastrillarlo en: CARIBBEAN FORESTER el verano anterior a la primavera en que sera sembrado, evitandose con esto una gran parte de las malezas. Una vez que la tierra ha sido labrada y nivelada, se comienza a construir las plataban- das o tablones. El ancho mas conveniente y economico es de 137 cms. en la “cara del ta- blén” y 46 cms. las platabandas para pasillos, lo que da un total de 183 cms. por tablon. Los tablones deben dejarse a una altura me- dia de 12 a 15 cms. sobre el fondo del pasillo para el desagiie necesario. Durante la tem- porada la platabanda pierde altura por la compactibilidad, reduciéndose a unos 7 6 10 cms. sobre el fondo del pasillo. Los pasillos se pueden abrir con arado, lo que permite de- jar la tierra a ambos lados y posteriormente arreglar los taludes con palas. La Siembra En Chile la siembra comienza el lro. de septiembre y termina alrededor del 15 de no- viembre. Para saber la fecha mas convenien- te para cada especie, es preciso tener experien- cia en el propio vivero con las mismas especies por 3 a 4 afios. A veces el tiempo o la con- dicién del suelo no permiten la siembra a su debido tiempo pero el atraso no se considera serio si no varia mas que 10 6 15 dias de la fecha anteriormente indicada. Inmediatamente antes de la siembra se de- be remover la tierra de las platabandas y pa- sar un rodillo. En lo posible se aconseja que el rodillo tenga el mismo ancho del tablon (137 cms.) y que pese entre 450 y 500 kilos, debiendo tener ademas un didmetro de no menos de 80 cms. hasta 1 metro. En el caso de que solo se disponga de un rodillo con la mitad del ancho y del peso del arriba descrito debe pasarse dos veces. La tierra no debe apretarse demasiado. La compactibilidad correcta se obtiene cuando puede introducirse el dedo con facilidad 2 a 3 cms. de una sola punzada. Para lograr!o se pasa el rodillo 2 6 3 veces segtn sea nece- sario. JANUARY - JUNE 1956 Los surquitos o hileras se marcan y se abren con la ayuda de un rastrillo con clavos de maderas con puntos, que pueden ser chi- cos o grandes segun la especie a sembrar. El rastrillo ideal para la siembra de la mayoria de las coniferas y algunas especies de hoja ancha, es aquel que tiene las siguientes carac- teristicas: 130 cms. de ancho con ocho clavos a una distancia de 152 mm. entre ellos, medi- dos de centro a centro. La profundidad de los surquitos l6gicamente depende de la se- milla; generalmente la profundidad debe ser sélo dos veces el didmetro de la semilla. Si las semillas son oblongas se usa el promedio de las dos medidas. En los casos de pino in- signe, maritimo y caribe (Pinus elliotti En- gelm.), la hilera se abre a una profundidad de 10-12 mms. La profundidad de la siembra es de suma importancia. En la mayoria de los casos la siembra se hace demasiado pro- funda. Para que las hileras resulten derechas se puede guiar el rastrillo por una cuerda de alambre. Es mas practico sembrar en hile- ras a lo largo del tablon en vez de atravesado. En el caso que al pasar el rastrillo se vaya acumulando tierra o basura, sera necesario limpiar los clavos para evitar que la perfora- cidn sea muy ancha. Las semillas se tapan con una mezcla de tierra y arena; la proporcidn depende de las caracteristicas de la tierra del vivero y en ca- da caso tendra que ensayarse una mezcla se- gun el tipo de tierra. El objeto de emplear arena es para evitar la formacion de una cos- tra dura, lo que podria impedir la salida de las semillas finas. Debe evitarse usar un ex- ceso de arena para evitar que la tierra s2 se- que demasiado rapidamente. En chillan se usa _una cuarta parte de arena y tres cuartas partes de tierra. La arena y tierra, deben pa- sarse por un tamiz o cedazo al mezclarse. La arena debe ser limpia y la tierra procedente de una capa situada entre 5 y 20 cms. de la superticie, para evitar que venga acompafiada de semillas de malezas y esporas de hongos. Una vez que las semillas han sido sembra- das las semillas se cubren con la mezcla de 43 tierra y arena. Este trabajo se ejecuta a ma- no con mucha precisién, pues las semillas sdlo deben quedar cubiertas a una profundidad igual a su didmetro, una vez que haya sido pasado el rodillo. Las semillas forestales, es- pecialmente las de coniferas, deben ser sem- bradas superficialmente, en ningtin caso nun- ca mas profundamente que su propio didme- tro. Para lograr cierta perfeccidn en este res- pecto sera necesario que los tapadores rea- licen previamente ciertas pruebas antes de proceder a taparlas definitivamente. El tra- bajo de los tapadores requiere ser revisado para asegurarse que no “recargan la mano”. Una siembra de coniferas bien hecha, a una profundidad correcta, siempre dejara, después del primer riego, algunas pocas semillas descu- biertas lo que caracteriza a una buena siem- bra. Luego las semillas que hayan quedado al descubierto, se cubriran de nuevo, sobre to- do si son de mucho valor. En relacién al sistema de siembra no es recomendable regar al voleo debido a que no es posible controlar con precisién la densidad deseada de plantas. Ocurre a menudo que con este sistema, se derrocha terreno o semi- llas, debiéndose proceder posteriormente al raleo de plantas; en cambio, con el método de siembra en hileras se logra un cultivo me- jor y mas econdmico, al mismo tiempo que se facilite la labor de desmalezadura. Una vez sembradas y tapadas las semillas se pasa de nuevo el rodillo sobre las plata- bandas. Damping-off y la Aplicacién del Acido La enfermedad provocada por los hongos, llamada “damping-off” es comtin en los vive- ros de Chile habiéndose registrado pérdidas completas en el breve transcurso de 2 a 3 dias. Ei primer sintoma aparece en el tallo en la forma de pequefios puntitos de agua: al cabo de un dia la plantita se marchita. Esto ocu- rre generalmente en grupos y si ademas las condiciones son favorables para el desarrollo del hongo (tiempo caluroso, himedo y sin viento) la destruccién puede abarcar grandes extensiones de plantas en pocas horas. Esia 44 plaga es la mas temida por los técnicos de vi- veros. Entre las medidas que puedan tomarse contra esta enfermedad se pueden desiacar las siguientes: ubicar el vivero en un sitio ventilado pero que no lo sea en exceso; seguir una rotaci6n tal que no se siembre en el mis- mo terreno 2 anos seguidos; tapar las semillas con tierra y arena extraida de capas situadas a una profundidad de 30 a 50 cms. de la su- perticie; desinfeccién de la tierra con fungi- cidas. Todas estas medidas son eficaces y ne- cesarias, particularmente las dos tltimas, pues contribuyen ademas a disminuir la cantidad de malezas. Por ser muy efectivo, barato y facil de apli- car, se recomienda la desinfeccién de la tierra con acido sulftrico. Una vez terminada la siembra, se aplican 3 litros de una soluci6n de 1.5 por ciento de acido por metro cuadrado de terreno. Para preparar la solucién se co- locan 9 litros de agua en una regadera de 10 litros de capacidad y se afiaden 200 cms. cu- bicos de acido de 66 grados (tipo comerciai) revolviendo la mezcla. En el manejo del acido sulftrico siempre se debe anadir acido al agua y no agua al Acido lo cual es peligre-o. Se deben tomar to- das las precauciones necesarias. Los obreros que manipulen el acido deben usar lentes pro- tectores, guantes largos de goma, pantalones y botas de goma; en caso de accidente debe mantenerse una solucién de bicabornato de sodio para lavarse, y una copita para lavarse los ojos. Los 9 litros de la solucién se aplican en 3 metros cuadrados de piatabanda. Para medir el drea, lo mas practico es hacerlo con un mar- cador que marca un tramo de 2.19 metros de la platabanda que tiene 1.37 metros de ancno v cuyo producto de exactamente 3 metros cuadrados. Al cabo de 3-4 dias, si no ha Ilo- vido, se vuelve a diluir el Acido con un buen riego de regaderas. En cualquier tratamiento o cultivo nuevo, es necesario dejar testigos no tratados, ya que | CARIBBEAN FORESTER ésta es la Unite manera de comprobar con exactitud la bondad Ge los tratamientos. Ya habiamos dicho anteriormente que el trata- miento con acido no s6dlo -$ ——= 1954b. Research methods and records connected with the tropical shelterwood system in the Gold Coast. Emp. For., Rev. 33:150-157. (73) Trevor, C. G. 1935. Natural V. artificial forestry. Emp. For. Jour. 14:25-26. (74) Turner, M. R. y J. P. Veillon 1949. Estudio de las zonas forestales del estado Portuguesa. Mi- nist. de Agricultura y Cria, Caracas. 65 p. (75) Veillon, J. P. 1954. Unos aspectos forestales del Peri. Bol. Fac. Ing. For. ULA, Mérida, 1(6):3-36. (76) Wadsworth, F. H. 1945. Further notes on the regenera- 75 tion of Tabebuia pallida Miers. Caribbean Forester 6:267-269. 1947. An approach to silviculture in tropical America and its ap- plications in Puerto Rico. Caribbean Forester 8:345- 356. (78) 1948. Five years of forest research on the north coast of Puerto Rico. Caribbean Forester 9:373-376. 1949. Ninth annual report and _pro- gram. Caribbean Forester 10:81-119. (80) Walton, A. B. 1954. The regeneration of Dipterocarp forest after high lead logging. Emp. For Rev. 33+ 338-344. (81) Walton, R. C. Barnard and J. Wyaitt- Smith. 1953. Silviculture of lowland Diptero- carp forest in Malaya. Un- asylva 7:19-23. (82) Wilten W. 1955. Aspects de la sylviculture au Mayumbe. Bull. Agr. Congo Belge 46:319-328. (83) Wyatt-Smith, J. 1951. Forestry, agricultural _ settle- ments and land _ planning. Malayan Forester 14:206-212. 76 CARIBBEAN FORESTER Regeneration Systems in Tropical American Lowlands (Translation of previous article) GERARDO BUDOWSKI Inter-American Institute of Agricultural Sciences - Turrialya, Costa Rica INTRODUCTION One of the most important branches of tropical silviculture is undoubtedly the re- generation of mixed forests. It is well known that current forest explo- tation in most Latin American countries is really a negative selection of valuable species or “high grading’’, since only the best trees are cropped leaving the space open to other non-commercial species. With the addition of damage from repeated fires, uncontrolled grazing, shifting agriculture, and lack of re- generation practices, the overall picture is disheartening; it is easy to understand why the forest economy and welfare of many re- gions are in a deplorable state. Countries such as Cuba, E] Salvador, and Puerto Rico, once covered with forests, are forced to import practically all their lumber needs and other forest products. To this may be added the fatal consequences on waterflow and the na- tive fauna, and the absence or scarcity of re- creation zones for urban populations. All these amourt to a very high price for the lack of foresight. Many other countries have suffered a similar fate since few forested re- gions have been left close to population cen- ters. Even in rural areas, prices for lumber, firewood, posts, and other similar products have become prohibitive in recent times. It should not be assumed that Governments have remained indifferent. There is an ac- cumulation of laws which, according to many Government officials, are apparently excel- lent. In practice, however, they are more or less disregarded. Despite continuous changes or rigid enforcements of these laws, the situa- tion not appreciably changed for the better. Huge reforestation programs have been lauch- ed, usually through free distribution of seed- lings, a policy that unfortunately still seems to enjoy much popularity. Beard (23, p. 18)?/ once commented that: “Tropical forestry in nearly every country in which it has been practiced, has suffered in its youth from a disease that has been called “planting meas- les”, a fixed idea that it was necessary to start forming plantations at great speed all over the place, often without any previous research. After the wastage of much money, the program was revised in favor of less costly, more natural methods, based on careful ex- periments.” The forest history in Latin America is full of these failures (47) and, although some have been publicized (69, 30), most of them have never been reported. It is apparent, however, through the annual reports of the forest services of Ministries of Agriculture of many countries, that many seedlings have been distributed; later examination of plan- ting sites corroborates the wastage in effort and money. This has been recently confirm- ed by the Guatemalan Forest Service, after an investigation undertaken concerning the fate of millions of seedlings distributed in re- cent years. The results were most disappoint- ing. True, it is easier to criticise than to find definite solutions. It is a primary requisite that wildfire and unrestricted grazing be controlled before any 1/ Numbers in parenthesis refer to Literature Cited, page 70. JULY - DECEMBER 1956 attempt is made at forest regeneration. Even after this protection has been attained, many questions still remain unanswered. What species are to be used? How and vhen shcald they be planted? What care do plantations require? Perhaps instead of planting it is possible to induce naturai regeneration through adequate interventions. Finally and more important than all pr2viors interroga- tion - How can the desired result be achieved with a minimum of expenditures and a maxi- mum of efficiency? The answer to these questions is in the scope of this article. An analysis of past ex- periences, especially of successful ones, will give many clues. The practice acquired in other tropical countries wil be very useful since conditions are often duplicated. This presentation of experiences gained elsewhere may be useful as publications pertaining to silvicultural systems applicable in tropical America are limited. It is Preferable to Work with Forest Soils It should be remembered that it is easier to revert a denuded area into a forest when- ever this happens on a forest soil rather than on a degraded savanna soil. The latter is usually more compact with deficient or exces- sive drainage and often with additional special problems. It is often an illusion to think that reforestation of areas ruined by repeated fires, shifting agriculture, and unrestricted grazing can be accomplished unless large sums are invested for irrigation, fertilizers, digging holes for planting, or raising costly nursery plants. If a watershed is to be re- forested, probably the best thing to do, as- suming an adequate seed source is to protect it so that natural succession towards forest may take place. If this process of natural succession is to be hastened, pioneer species should be used or natural seedlings should be liberated from weeds and grasses (52, 29). At any rate, this is an arduous and costly process and certainly uneconomical if the goal is to obtain lumber or other direct forest id products. Much easier, and with good econo- mic prospects, is the regeneration of an exist- ing forest, even if it is degraded. CURRENT REGENERATION SYSTEMS USED As a general rule, most of the forests are actually unproductive in an economic sense regardless of whether they are virgin or de- graded. This is mainly because of their he- terogeneous composition with only a small amount of commercial timber present, logging costs are usually high. Thus, it is generally agreed that an alteration of the composition, particularly in regard to structure and num- ber of species, is highly desirable (41, 42). This is what Dawkins (37) has called “‘refin- ing” - to render the idea of conversion in- to more valuable material. However, this con- version should be made with due regard for ecological conditions so that the new stand to be formed will not only be healthy, but also self-sustaining and permanent (63). The regeneration methods used fall cur- rently into three broad groups (38): 1. Since the existing forest offers little of commercial value, clearfelling is prac- ticed and the old stand is replaced by a more even-aged crop, recruited from artificial or induced naturai_ reger- ation. 2. The stand is enriched by the artificial introduction of valuable species. This methodical underplanting is usually done in combination with systematic openings in the canopy in the form of lanes or strips of variable width and at different intervals within the forest. 3. Natural regeneration is induced under partial shade or protective shelter through careful and gradual opening of the stand. The purpose of such a gradual opening is to induce more and better reproduction and the develop- ment of a new, more valuable crop of trees. This system is generally known as “shelterwood”. Spanish terminology translates it to “cortas uniformes o cortas progresivas y aclareos sucesivos’ (44) or “regeneracién bajo cubierta pro- tectora de pies de masa _ reservados, previa una corta a hecho o rasa, y otra ulterior” (48). In this paper, “regene- racion bajo dosel protector” (literally: regeneration under protective canopy) is used. Each of the three systems has its own best applicability, advantages, and drawbacks, ana all factors must be carefully evaluated before deciding which to adopt. Even if some intergrading may occur it can, however, be said that one system can best be applied when certain definite conditions prevail. (1,-43, 71). Regeneratios Through Clearfelling It is noticiable that this system faces al- most automatically, the reproval of a good number of foresters who claim it is dangerous and too drastic. Although dangers may be found when the forest with all its favorable influences is removed, there is no question that under favorable conditions, this system has been very successful in different tropical lowlands. Before going into details, it is advisable to review briefly the natural process that would follow clearfelling if no further intervention were made. It has been adequately demon- strated that the land will return to forest although the first arboreal vegetation that follows, i.e. the weed, brush and climber stage, is far from being similar in composition to the original stand (1, 13, 53). A number of fast growing species are the “invaders”. Their seed is light and easily dispersed by wind. Musanga spp. and Trema spp. are the most common examples in Africa, while Ce- cropia spp., and to a lesser extent, Ochroma lagopus Sw., Trema micrantha (L.) Blume, and Schizolobium parahybum (Vell.) Blake are striking examples in Africa. These species usually have very soft wood which deterio- rates rapidly after felling; only recently have CARIBBEAN FORESTER they received any consideration for possible economic uses. They do not, however, per- sist indefinitely and give place to other species that germinate and grow under their shade. After several stages of succession it can be assumed that the whole stand will return to the composition of the original forest or at least something quite close to it (45, 58). However, if the soil is cultivated for several years following clearing, and _ this often happens when the usual method of shift- ing agriculture is used, a lower form of herba- ceous vegetation, specially grasses, becomes established and is likely to persist for a con- siderable time (81, 11). In the succeeding years, there is also a rapid deterioration of the soil since it loses its protective cover and remains exposed to rains and solar radiation (26). More than losses in organic matter and nutrients, this degradation involves soil compactation and the formation of hard pans, often iron concre- tions, with impeded drainage, especially on flat areas. If the vegetation is continuously kept down by fires, a poor, fire resistant sa- vanna may be the final result. This leads to the statement that if a valu- able forest cover is to be established after clearfelling, it must be done very soon. Nurs- ery grown stock is generally used in order to give the young seedlings an additional ad- vantage in the race with the natural vege- tation. The “Taungya” System Based on clearfelling, some of the most spectacular successes have been achieved with the taungya system originated in India. It is commonly used in Asia, Africa, and ap- parently with promising results in Trinidad and British Honduras. Essentially, it consists of using the forests for agricultural purposes during a limited time; the forest is felled, burned, and the land planted with crops. With the first rainy season, seedlings or root and stump cuttings of valuable tree species, are planted and cared for by the provisional JULY - DECEMBER 1956 users of the land as a partial compensation for its use. When crops are weeded, so are the seedlings. When cropping is over and the area is abandoned, it is already planted. The young trees wiil not thrive without attention, to be sure, since several silviculture operations such as cleanings or thinnings are essential. Thus the operation starts with very little cost and actually there might be some profit because some of the fallen timber may be util- ized or sold. The harvesting of excellent agricultural crops following deforestation is good compensation for nursery and plantation costs. A further refinement is achieved in Trinidad on crown forests where charcoal can be made profitably from the remaining species that are useless for timber. Teak (Tectona grandis L.) is then planted a3 root and stump cuttings. After 2 years, the same process is repeated in another region. So far, about 3,500 ha. (8,750) have been “‘convert- ed” through this scheme (8, 31). in the Belgian Congo, the taungya system has been successfully used in combination with banana planting. When located along or close to the rivers, the forests can be eco- nomically clearfelled because there is an ex- cellent market for firewood for steamships. In both cases Terminalia superba Engl. & Diels is planted. Here too, the operation starts with a profit-yielding harvest but it is later necessary to keep the competing vege- tation in check. In eastern Belgian Congo, good markets for firewood have made clear- felling a profitable operation. Here Termina- lia superba, Khaya grandiflora, K. anthotheca and Fagara macrophylla were planted. Ali these species are fast growing and strong light demanders (54). Other countries report similar experiences; in British Honduras pine (Pinus caribaea Mo- relet) is planted after the brodleaf forest is felled (7, 64), in India (2, 56), in tropical Australia (9), West Bengal (6), and on the island cf New Britain in the Pacific Ocean in connection with the establishment of Eucalyptus deglupta Blume, a valuable and very fast growing native species (49). The 79 taungya system has been applied in many African countries (3) and in many parts of the tropics in general. As can be seen, the characteristic features of the taungya system are the planting of valuable, fast growing, and light demanding species; the best economical utilization of the forest; and the temporary short cultivation of the soil, related of course, with the special land tenure pattern. When one or more of these factors is lacking, the system is likely to become expensive or entirely impracti- cable. In case there is not enough demand for farming land, or when the population is not accustomed to a rotating or shifting sys- tem of agriculture, or when all the different processes of the system cannot be adequately controlled, serious handicaps may arise and failures are to be expected (4, 61). In Hondu- ras, Guatemala, and other Central American countries, the United Fruit Company as well as other private owners have established some plantations, especially with teak (Tec- tona grandis L.), primavera (Cybistax donell- smithii (Rose) Seibert), mahogany (Swietenia macrophylla King) and Eucalyptus deglupta Blume. There were heavy initial investment because apparently little or no use was made of the fallen timber and the soil was not cul- tivated. According to the Fruit Company, however, the high value of the new-grown timbers will compensate for the investment. Apparently this is also the case in other places where similar plantations have succeeded with mahogany in the Philippines (34), with okoume (Aucomea klaineana Pierre) in Mar- tinique (33) and in Africa (16). Some experiences with the genus Eucalyp- tus have been particularly successful, both at higher and lower elevations (12). In Cuba, a mining company has initiated plantations with Eucalyptus saligna Sm. with results which so far have been very promising - far more than had been initially expected. The original forest was very degraded and practi- cally without commercial value. The latest plantations, however, have been initiated on 80 ploughed savanna soils and apparently with similar success. Initially the reforestation scheme was aimed to demonstrate the good faith of the company in forest conservation since large quantities of pine (Pinus tropica- lis) were being cut for mine timber. Actually, besides fulfilling legal obligations, it appears that the plantations are also an economic success. Growth is amazingly fast and some of the best trees measure 90 feet in height (27 meters) and a diameter at breast height of 14 inches (36 centimeters) after only 5 years. Some of the trees are already in ser- vice in the mine, having been previously treated with preservatives to build up resis- tance against fungus. The ecological condi- tions make the zone fit into the tropical dry formation of MHoldridge’s climatic scheme (51), with a mean annual temperature of ap- proximately 25°C and annual precipitation of 1,600 mm. Many other species have been in- vestigated as to their ability to grow under similar conditions (63, 27, 3). Advantages and Disadvantages of the Clearfelling Method Among the most noticeable drawbacks that have been denounced for this method is the radial ecological change involved. The soil is exposed and, without its protective cover, becomes, highly susceptible to degradation. That is why it should never remain exposed for a long time. Sandy soils leach very easily while clayey soils have a tendency to become compact and hard with resulting drainage troubles. A short exposure, however, is not dangerous. That is one reason why many tropical soil scientists defend the so called “primitive” agricultural methods, where short rotations at the expense of the forest are involved. When sprouts are allowed to de- velop and weeds quickly cover the abandoned field, protection is effectively secured. Another disadvantage is, that since most of the successes have been obtained with exotic species in pure plantations, there is a danger of insect and disease spread (73, 59). CARIBBEAN FORESTER So far, teak and Eucalyptus spp. have ap- parently been resistant to any harmful ef- fects of such treatments but other plantations have shown some symptoms. Attacks of a fungus (Pestallozia) and insects have been reported in okoume (Aucoumea klaineana Pierre) planted in Africa (15). Among the Meliaceae, the shoot borer (Hypsipula gran- della) has caused extensive damage (50, 63). For this reason, wide spacing is often used in the taungya system, with an aim of cre- ating a mixed forest composed of a consider- able proportion of valuable planted trees in- termingled with trees of natural origin (54). This certainly appears to be much less ex- pensive than keeping all the natural vegeta- tion in check as is often practiced. Some of the United Fruit plantations in Central Ame- rica have been kept cleaned. Furthermore, good form can be economically achieved by this lateral shade. Normally, under the re- gular system of planting, the number of trees would have to be reduced in closely spaced plantations by thinning. The idea of establishing mixed plantations with one or two species has been advocated by some technicians, but experience is lack- ing on the subject. In Cuba, a small area was planted with a mixture of teak, majagua (Hibiscus tiliaceus L.), and local mahogany (Swietenia mahagoni Jacq.). After several years a few specimens of teak and majagua remained in good condition: mahogany, how- ever, because of its slower growth, was being wholly suppressed. If there is no reasonably good market for products from the felled original forest and no demand for temporary agricultural use of the land, the initial costs of the method will likely become prohibitive. Still, assuming that these conditions can be solved as in the Belgian Congo, there remains the difficulty of controlling the native agricultural practices as well as ensuring careful handling of the planting stock. In Trinidad only certain crops are allowed and only for a very limited time (31); a regular contract is usually drawn up and many other precautions are taken. JULY - DECEMBER 1956 The system of land tenure appears to be a fundamental factor in making “taungya” work. How it would succeed in other coun- tries where patterns of land tenure are differ- ent remains to be seen. In Latin America there is already a complicated problem caused by the so-called ‘“‘conuqueros’, “parasitos” or “precaristas” (The English equivalent would be “‘squatters”). The name changes in the different countries but the people involv- ed are essentially the same. They practice shifting agriculture on land which is not their own. In fact they are protected by different laws. It is difficult to predict how the taun- gya system would be received, under such conditions. Displacement of rural people has always proven to be a delicate problem since economic, social and political factors are in- volved. This does not mean that the system is bound to fail. Grouping these “wandering farmers” or “squatters” into organized com- munities or cooperatives with a definite work- ing plan might be the solution to the prob- lem and taungya might be the tool with which to accomplish this long desired ob- jective. A definite limiting factor of this system is the choice of species. The foregoing ex- periences show that they must be fast grow- ing, light demanding, and of course, valuabie. The first two conditions are essential because suppression by the natural incoming vegeta- tion should rever be allowed and the cost ot cleaning should be kept to a minimum. Caring for Natural Regeneration after Clearfeling With increasing silvicultural knowledge, it becomes gradually more evident that the natural “invaders” coming in after clearfelling have so far received insufficient attention. This is rapidly changing and the new situa- tion may be attributed mostly to the increas- ing market for the so-called soft hardwoods however perishable. One example is furnished by balsa (Ochroma lagopus Sw). formerly considered a weed but now often prized when 81 it appears in abandoned fields. In Pert, ex- tensive natural clearings are made each year by the changing ccurses of the rivers. Dif- ferent species of cetico (Cecropia spp.) estab- lish themselves readily on these open lands. They are being seriously considered as a source of puipwood as they can be harvested aiter only about 4 years (75). This may lead to silvicultural system intended to pre- pare land for this crop. The genus is well represented in all tropical American coun- tries, where it is ussually called yagrumo, guarumo, embauba, etc. All its species are aggressive, intolerant, and very fast growing. In Puerto Rico, a valuable tree (Tabebuia pallida Miers) is able to establish itself on poor degraded soils even when covered with grass, certainly a limiting factor for many other species. The management of this spe- cies has shown much promise (76). Finally in Costa Rica and other Central American countries, a good timber tree (Cordia alliodora R & P Cham) appears readily on cleared forest land even after pas- tures have been established. Many land own- ers do actually appreciate this valuable in- vader and when releasing their grass from brush, they carefully avoid removal of that species. It has been shown that a few silvi- cultural operations are able to return high yields and profits (67). No clearfelling is done at present for the definite purpose of regenerating Cordia alliodora but rather for establishing pastures. However, this situa- tion may reverse with the increasing value of the timber of this species. It may be stated in conclusion that clear- felling appears to be a very promising system when conditions are favorable, and good con- trol can be achieved in all stages of stand de- velopment. The fact that only intolerant fast growing species can be grown properly by this method limits its use to a considerable ex- tent. However, some of the valuable timber species actually have these characteristics; the demand for others is increasing because of new markets. Early production of clear wood that can be harvested under favorable 82 economic conditions is becoming very attrac- tive; the clearfelling method appears to be a good silvicultural tool to achieve that aim. Regeneration Through Artificial Enrich- ment of the Forest in Strips This system, most popular in Africa es- pecially in the French colonies, consists es- sentially in opening strips of variable width and planting nursery grown seedlings or sow- ing seed of valuable species that are adapt- ed to their new environment. The system aims at several goals. Instead of clearfelling the forest, only strips are cut through it. Thus, labor is saved. Natural environment is also maintained to a_ better degree and finally, and important from the silvicultural angle, there is lateral shade and overhead light to stimulate straight growth with few lateral branches. The method in- deed looks satisfactory if given only theoret- ical considerations. Practice, however, shows serious limitations and even though some of the results are promising, many species have not succeeded in fulfilling the hopes. Here too it seems essential to first study the eco- logical habits of the introduced species. The condition of the criginal forest is also im- portant since different results were obtained depending on whether it was low and secon- dary or high and primary. Finally, serious consideration should be given to the eco- nomics of the system, especially in relation to the labor necessary to open and clean the strips. Spacing varies in the different zones where the system has been practiced. In the Gold Coast, the strips were 1 chain (20 meters) apart and 6 feet (1.8 meters) wide. Nursery grown species are stripped of their leaves and planted when 3-5 feet tall (0.90-1.50 meters) at a distance of 33 feet (10 meters) within the strip (4). However, it was later neces- sary to clean the strips to avoid conti- nuous encroachments of the nearby forest, with considerable increase in costs. In the Ivory Coast, the strips, originally set at CARIBBEAN FORESTER 33 feet (10 meters), were later increased to 82 feet (25 meters) to avoid cosily cleanings (17). Similar problems were found by the Fays and Huygen (43) in the Belgian Congo. They suggest that in order to avoid excessive cleaning costs, only plots of 13 x 13 feet (4 x 4 meters) should be open- ed every 33 feet (10 meters) along the strips with one plant for every square meter within the plot. All species dealt with were rather intolerant, that is light demanding and suf- fering from competition of adjoining trees. The importance of adequate light and lateral shade is well known in tropical silviculture. Wadsworth (78, 79) drew the conclusion that upon this balance depended the activity of destructive vines and other noxious species that needed plenty of light. He suggested that any opening of the forest must be kept within certain limits and suggests that 60 percent of shade is sufficient for the trees to keep their good form and also to avoid exces- Sive activity of vines. In some forests of Puerto Rico these openings can be made by harvesting some of the trees used for posts. In this manner the initial preparation costs can be reduced to 30 percent because of the value of this crop. The demands for lateral shade may be so specific in some cases that Dawkins (35) reports a case in Uganda where nurse trees of Cassia siamea Lamb. and Eu- calyptus spp. were planted to provide lateral shade for a plantation of Chlorophora excelsa (Welw.) Benth. Perhaps the most ardent defender of this system is the well known tropical forester A. M. Aubréville, wno in a long series of pa- pers (10, 14, 15) reports on the successes at- tained and some of the handicaps encoun- tered. Some of the experiences date back 20 years. The conclusions that can be reach- ed after studying Aubréville’s observations in- dicate that there are great variations accord- ing to the regions and the different species (36). The most successful trials indicate that the most suitable species for this method are also the most intolerant, although generally not to a degree to permit pure plantations JULY - DECEMBER 1956 without restrictions. African mahogany (Khaya senegalensis A. Juss and _ other Khaya spp.) and okoumé (Aucoumea klaine- ana Pierre) were particularly successful. How- ever, it was never possible to avoid cleaning of natural vegetation that came along the open strip, as well as the encrouchment oi the lateral forest, trying to close the gap. Even after 20 years, some of the trees needed cleaning in a plantation where 33-foot (10 meters) strips were opened every 66 feet (20 meters), with trees planted every 16 feet (5 meters) within the strip. A fungus (Pestal- lozia) and some insect damage was also re- ported although never reaching an alarming stage. The plantations of Chlorophora excel- xa (Welw.) Benth were also attacked by another insect, Phytolina lata (46). The costs of the strip plantations have been calculated in different regions. Le Ray (60) reports 136 man-days per hectare (55 man-days per acre) after 5 years, but Bellou- ard (25)lists only 47 and 57 man-days per hectare (19 and 23 per acre) for two 15-year old plantations where 243 and 221 trees re- spectively were left per hectare (98 and 89 per acre). These experiences came from dif- ferent African regions. There is one point of mutual agreement among silviculturists: the possibilities of suc- cess are greater when the forest to be treated is of medium height. When primary with high trees, the canopy is difficult to control (9, 65, 25). Wilten (82) suggests the previous girdling of all emergent trees. Since secon- dary forests are usually found close to pop- ulation centers, labor is handy and there are good market prospects for some of the prod- ucts from the strip openings and further thinnings. (See Fig. 1, p. 60) In tropical America, the United Fruit Co. and some Mexican lumber companies have established some strip plantations in Hondu- ras and Northern Yucatan Peninsula respec- tively. The species used were mostly cedro (Cedrela mexicana L.) and broadleaf maho- gany (Swietenia macrophylla King). It is premature to judge the value of this system 83 before studying the technical results and the costs. Apparently, the problems of competi- tion from the adjoining vegetation have in- duced high maintenance costs. Direct Seeding and Its Variations An important variation of the system in- volves direct seeding in the opened strips instead of planting nursery grown stock. In Africa this has been practiced with okoumé (Aucoumea klaineana Pierre) (60). It is im- portant to seed speedily once the seod has been collected since viability is of very short duration lasting about 3 weeks. In Mexico the system is extensively pzac- ticed with Spanish cedar (Cedrela mexicana L.) on the rather dry calcareous flats north of the Yucatan Peninsula. Instead of strips, abandoned logging roads are seeded. After 2 years the seedlings looked very thrifty. At that time the damages of the well known shoot borer (Hypsipyla grandella) were insig- nificant. According to local foresters, some 20,000 ha. (50,000 acres) have been reforest- ed by this method. Since the seed of this species also looses its viability shortly after ripening, it was important to store the seed under cold temperature after collecting in February or April so that it can be sown af- ter the rainy season starts in June. On these secondary logging roads where tractors and trucks had passed, the mineral so] was ex- posed and ready to receive the seed broad- cast by a worker. The Mexican foresters claim that this system has reduced the cost of reforestation by 50 times per hectare if compared to usual methods of planting with nursery-grown stock on cleared strips through the forests. The density of regeneration is such that it soon becomes necessary to thin the saplings. By direct seeding there is no need for nurseries and costly field planting. However, a great quantity of seed is necessary for these large areas. It must be convenient- ly stored in accessible cold places. The dif- ficulty in obtaining the seed, especially in re- lation with labor must also be taken into 84 account. All these factors however, should be capably handled with a minimum oi invest- ment by efficient organization. The idea to store seed and then broadcast it when the rains begin on places where mineral soil has been exposed, may possibly appear to be a very simple one. However, if the Mexican experience can be applied in other countries and with other species the practice could prove of great significance to tropical for- estry. It might be interesting to note that the silviculture of Cedrela had probably re- ceived more attention in tropical America than any other species without, so far, solv- ing the problem of satisfactory regeneration. (See Fig. 2 p. 61) The Mexican scheme ap- pears to fit very satisfactorily with current methods of logging in regions where the for- est is dry (or tropophyllous or deciduous). A well marked dry season in these regions limits lumber exploitation to a few months and implies the construction of provisional logging roads. At any rate the Mexican method has in its favor the very low costs; it would be very interesting to have other coun- tries experiment on the same problem. Regeneration Through the She:terwood System Many of those ecologists who have studied succession in tropical forests have long known that it is possible to induce regeneration un- der the natural forest shelter. Yet his obser- vation has only recently been applied in sil- vicultural practice. The tropical shelter- wood system was evolved and is now very much in favor (70, 62, 39, 71). Not only is regeneration assured but the young trees in the sapling stage seem to grow well later if release from competing vegetation is skillfully accomplished. Kssentially a. natural process that would occur without man’s intervention is followed but a gain in time and selection of commer- cial species is aimed at. That is why the word “refining” has been used to render the idea of conversion of a heterogeneous forest CARIBBEAN FORESTER with most species of little value, into a stand of fewer species of much higher value (37). The Different Phases of the Shelterwood System Two main operations are usually involved in the process of refining the stands: (a) seed cutting aimed to favor good reproduc- tion, and (b) removal cuttings to favor the growth of valuable seedlings and saplings un- til all the shelter is eliminated. Both opera- tions can merge into a single one in some especially favorable cases which will be con- sidered first. The Refining of the Dipterocarp Forest and its Repercussion in Tropical America The particular nature of these forests, rather rich in valuable species, enables the achievement of their refinement in what may be considered the simplest form of the shelter- wood system in the tropics. Yet even under the prevailing favorable conditions this scien- tific approach is rather recent and_ strangely enough, the result of what was initially con- sidered to be a destructive practice. In effect, it was felt that the forest would not survive the damage resulting when the primitive methods of hauling timber with buffaloes were replaced by the _ highlead logging method using modern machinery, and involv- ing the harvest of a considerable number oi trees per acre. However, very a satisfactory amount of seedling and saplings, often 600 or more per acre (1,500 per ha.) were counted 1 year after such a logging in Malaya (80). Further investigations revealed that, where windthrow damage had taken place or in- tensive logging had been carried out under the Japanese occupation, the forest was also behaving favorably and a new generation was coming up in dense pole stands under the slash. At this point one might gain the im- pression that under modern logging methods, clearfelling is done and regeneration secured. JULY - DECEMBER 1956 This is however, not the case; clearfelling is in fact criticized, because the land is leit open to the invasion of Imperata grass, which later proves to be very hard to eliminate (83). Actually, even in the richest Dipterocarp forest, the logging of the commercial trees takes only a part of the total standing trees, leaving a considerable amount of valueless trees, either of non-commercial species or too poor in form to be harvested. Evidently the dense reproduction normally present under the forest was just waiting for some kind of liberation. The removal of a large amount of the cover gives them that chance and also favors more germination and the establish- ment of new valuable regeneration. It is true that such reproduction includes again a great number of different species many of which may be of low value. At this young stage however, an easy elimination of undersirable species can be early achieved under very eco- nomical conditions (21, 81). The shelterwood system is now widely practiced in Malaya and logging permits are granted with no restrictions on the amount of timber to be harvested on government land. In addition, the permit specified that the re- maining noncommercial trees be either re- moved or killed very shortly after logging. It is, however, important that previous count- ings show a good stocking of advanced repro- duction before logging is allowed, and it may sometimes be necessary to wait for good seed years. However, annual establishment of re- generation appears to be the rule rather than the exception. The sudden opening will certainly stimulate a considerable in- crease in the activity of climbers and, as a result, a kind of mat may be formed over the new canopy of small trees. It seems, however, that the saplings are not too seriously af- fected and will eventually push through, an important phenomenon which cannot be easily matched in other tropical countries after similar operations. Cleanings of course become necessary in due time and are conduct- ed at regular intervals during subsequent years in addition to the first thinning. ® S5 Possibly one of the most favorable features oi the Dipterocarp forest is the presence of good advanced reproduction under the natu- ral shelter. This condition has been described for other tropical forests but is only common in rather undisturbed forests or special as- sociations like swamp forests (39, 62, 24, 40, 68). It is most frequently encountered in stands where the trees bear heavy seeds as in the Mora forests of Trinidad, the Guianas, Venezuela, Colombia and Panama, in Prioria copaifera Gris (20), Carapa guianesis Aubl. Virola spp., all of them economically im- portant. They are usually found in rather pure associations or account for a large pro- portion of the components of the stand, quite similar to the percentage of the Dipterocarp species of the forests of the tropical Far East. There is no information on the application of the shelterwood system to regenerate these American species but it is known that clear- felling will not result in desirable reproduction even if a few seedlings or saplings are present. Weed species will come in and outgrow them. Seed Cuttings The favorable conditions of the Dipter- ocarp forests may be rated as exceptional if compared with other countries (32). Most of the forests that are sufficiently accessible to justify intensive silvicultural operations are often secondary and usually degraded. The most valuable species have been exploited and many undersirable species have reached great size. On the other hand, the presence of nearby population centers and the relative accessibility of these forests means that usually good local markets can be found for fuelwood, charcoal and small sized timber. This is an important advantage when im- provement or intermediate cuttings are con- ducted because it may lower the cost of some of the initial operations or even render some profit (18, 77, 53). Because of the degraded conditions, good natural regeneration is com- monly lacking. Seed trees of valuable snecies may not be present in sufficient quantities 86 in the forest. As a result of poor cutting practices, fire, and grazing, many weed species have invaded the open stand and cense underbrush may cover the ground. This is certainly common in many forests of India, Africa, and much of tropical America, especially around population centers. If the seed scurce is wholly inadequate it is evident that the shelterwood system cannot be util- ized and must be replaced by some other method of regeneration involving artificial restocking (71). There is, however, consider- able evidence that even with few seed trees of good species, good regeneration may come in after the forest has been subjected to some kind of intervention, often much to the sur- prise of the forester (49). In tropical Ame- rica this is often the case with valuable spe- cies like Cordia alliodora (R & P) Cham, Cedrela mexicana L., Swietenia macrophylla, King., Astronium graveolens Jacq., Bomba- copsis quinatum and others. They have winged seeds and are rather intolerant. Fur- thermore, even some valuable tolerant species with wingless or heavy seeds like those be- longing to the family Lauraceae will also ap- pear in the regeneration in spite of the ab- sence of nearby seed trees. This is evidently a result of the activity of birds and bats (40). Thus the forester’s problem becomes one of how to act in order to imitate or even improve these natural processes and to apply the tech- nique over a larger area under the most fa- vorable economic conditions. This can often be achieved with an opening of the stand but it is important to consider the intensity of removal, the kind of trees chosen, and the methods of removal. In Nigeria it was found that some initial openings of the stands definitely favored re- generation as well as the growth of seedlings already present. However, the degree of opening had a marked effect on the kind of regeneration obtained. With light cuttings, a great number of tolerant species appeared which later had a hard time progressing. On the other hand, too heavy openings favored the intolerant species as well as a_ large CARIBBEAN FORESTER amount of climbers and other weeds. Be- cause the regeneration desired was of both tolerant and intolerant species, it was decided that a small opening in the first year follow- ed by large openings later should be the right sequence. Ait this rate, the tolerant species will establish themselves successfully and achieve some resistance against later compe- tition with intolerant neighbors. These opera- tions were only possible when the forest had a normal structure, that is, a good proportion of trees occupying the different levels regard- less of whether they were valuable or not. If too many overmature trees were present or the oldest trees were only in the pole stage, satisfactory openings could not be regulated. The presence of a reasonable number of seed trees was also necessary (72). In Trinidad some _ spectacular successes have been achieved with the tropical shelter- wood system, more so because the forests to be treated were quite degraded (8 18, 238, 26). Here, an intensive opening of the stand was made in the lower and intermediate le- vels, keeping an overhead shelter. Outlets for charcoal burners could economically be utiliz- ed to remove those species not merchantable for other purposes. The expected reproduc- tion came in profusely and saplings of eight different valuable species developed very sa- tisfactorily under the shelter. Some of them were of wing-seeded species but others were evidently brought by birds. This emphasizes the importance of leaving trees just to pro- vide shelter and a roosting place for the birds which then leave the seeds in their drop- pings. One limitation of this system in Tri- nidad is that natural regeneration can be se- cured only on sandy soils, but has so far not been obtained on clays. In British Guiana the same system was practiced in the greenheart (Ocotea rodiei (Schomb.) Mez) forest, apparently with ex- cellent results. The lower stratum was com- pletely removed with the exception of green- heart seedlings and saplings. Vines were aiso cut and some of the upper canopy was opened JULY - DECEMBER 1956 according to the needs and conditions of the forest (19). What Trees Should be Removed The matter of possible harvesting of trees by these seed cuttings, leads to the important consideration of which trees or other vegeta- tion should be selected for removal (77) and at what time during the entire operation. There is general agreement among tropical silviculturists that all climbers should always be removed whenever any cutting is made. Climbers are most troublesome and so far as known, their activity is always in opposition to the best production of timber (37). Their activity will increase when a stand is opened and their growth is extremely fast. It is very important to remove them in the early sta- ges of the refining process otherwise they may encroach on different adjoining trees and tie them together, thus rendering later felling operations difficult. in addition to climbers, the trees usually fall into the following categories: 1. Trees oi small size. Most of them will never pass a certain level and usually develop poor form and are rarely of economic importance. Together with overtopped large trees they occupy the lower levels in the structure of the forest and are the first to be eliminated. 2. Dead trees. If they can be sold they should be removed regardless of the fact that ability to cast shade is mini- mal. Their presence is not really a nuisance except that they favor the en- croachment of climbers. 3. Overmature trees. They occupy consi- derable space and must sooner or later be removed; such removal must be timed and conducted carefully. 4. Immature trees of poor form or un- desirable species that reach the upper canopy. 5. Mature trees of undesirable species or poor form. 87 6. Mature trees of desirable species and good form. As can be seen there is considerable lati- tude in the selection of trees which are to be removed at an early stage so that optimum degree of opening of the stand can easily be achieved. Harvesting of some commercial trees, which is certainly an attractive possibil- ity, may even be possible. However, it should be clearly understood that such opportunities should not divert attention from the primary objective of securing adequate regeneration of good species. Too often the allure of an early financial return has ruined further chances for reproduction. The overall policy should always be the removal of all un- desirable species first leaving all the valuable trees for seed source. Only in the case of a forest with abundant seed trees of good species is there likely to be a possibility of doing some harvesting of timber. Where to Concentrate Cuttings The experiences in Africa and Trinidad also indicate that most of the operations should concentrate at the intermediate levels in the forest, leaving provisionally an over- head shelter. The question of removal of the ground cover or underbrush is another subject which is apparently not settled. The main idea is of course to secure an abundance of seed and a good seed bed (43). In most places, however the initial germination is good without need of any noticeable special site treatment. Ac- tually the serious mortality really takes place during the later development of the seedlings, which then require considerable assistance. The good reproduction usually found under undisturbed forest is further proof that ger- mination will take place under normal ground cover. It has already been pointed out that in the Dipterocarp forest no underbrush removal is required. Investigations in other regions, however, show very desirable results from pre- paration of good seed beds. For example, 88 Jacob (55) has described a situation in Assam, India, where an attempt was made to compensate for the paucity of desirable seed trees by thorough clearing of the ground. This was combined with the removal of most of the trees of the lower and middle levels of the stands in a radius of 20-30 feet (6-9 me- ters) around the seed trees. The regenera- tion secured was good but because the dis- tances between seed trees were sometimes large, further silvicultural operations were rather cumbersome and the whole lacked unity. Some of these openings later attracted elephants, buffaloes, and other animals which caused extensive damage, mostly by tram- pling. The system was therefore revised in favor of a less severe initial cutting followed by more gradual openings at later stages. In South India, the removal of the under- brush was not even enough to induce good re- production of such a valuable species as Dysoxylum malabaricum Bedd. Instead other less wanted species were obtained. Only after extreme measures were taken like raking the soil just before the seeds fell, frequent weeding or airect seeding seeds coated with red lead to prevent them from being destroyed by vermin, was the desired reproduction succes- sfully established (66). This appears to be exceedingly expensive at least if used in other regions where labor is not as cheap as in India. In conclusion, it appears that removal of the ground cover and the preparation of the seed bed are necessary in some situations but not essential in others. A good amount of underbrush removal and even some distur- bance on the soil is achieved regardless of intent mostly by trampling when the seed cuttings take place (57). Removal Cuttings Once adequate regeneration has been se- cured, the canopy is gradually removed. The selection of the species which must be re- moved has already been discussed but in the removal cuttings the value of individual trees CARIBBEAN FORESTER is far less important than the quality of the shelter they provide for the new crop. The method of removing the older trees is also an important consideration. While the canopy is gradually removed the seedlings and saplings demand continuous care to ensure their proper development (78, 79). 'Too rapid removal of the shelter will favor climbers and the establishment of weed species while the presence of a dense canopy will hamper the good growth of the saplings. In Malaya complete removal of the canopy is achieved in only 2 to 3 years but intensive cleaning operations are later neces- sary to keep the growing crop free of climbers and other weeks. In other places a period of 5 or more years may elapse before the new crop can be left on its own without any shelter (72). It seems impossible to arrive at any kind of generalization concerning the number of re- moval cuttings and the length of the period over which they are extended. The many variations in local conditions prohibit such generalization. The best criterion to be used is based on frequent observations and count- ings to determine the conditions of the new crop. Whenever an opening in the canopy is made, it is sound practice to accompany it by a good cleaning of the young crop trees. Again, emphasis should be placed on control of climbers. Silvicides and Girdling in the Shelterwood System The recent introduction of the use of sil- vicides in tropical forestry appears to be ex- tremely useful and widens considerably the practice of economic silviculture. The shelter- wood system seems to be especially suited to their use. The removal of unmerchantable trees with short boles and large crown is ex- pensive if they are to be felled and girdling often proves to be ineffective in killing such trees. If the tree is felled the large amount of debris may not only damage the reproduction or advanced growth but may also provide an JULY - DECEMBER 1956 excellent framework for climbers. In Nigeria no good method oi slash disposal could be found to counteract this effect (72). How- ever if poisoning is substituted for felling, the results are highly encouraging. The branches break off when the rest of the tree finally falls. Poisoning has the additional advantage of opening the canopy quite gradually, thus avoiding any sudden entrance oi strong light. This is very important because it checks climbers to scme extent and is usually best suited to the requirements of the reproduc- tion. In fact, a similar effect is usually sought in nurseries when the shade is gradual- ly removed over seed beds and planting stock. There seems to be no point in girdling or poisoning small trees unless extremely vigor- ous sprouts might occur and hamper the de- velopment of the crop. However, according to Barnard (21), poisoning should be apphed to climbers. He suggests dampening the cut end of the climber in a 1 |b. per gallon solu- tion of sodium arsenite in order to reduce coppicing. The practice of girdling Cecropia pz2ltata L., an American pioneer species, whenever open- ings are made, has proven very effective in Puerto Rico. It is possible that this species might be useful as a nurse tree because of its rapid growth and the ease with which it can be eliminated by girdling. Observation of many sequences of natural successions in trop- ical America certainly confirms the belief that Cecropia spp. oifer excellent shelter for the early development of many valuable species. With larger trees, poisoning is usually th= practice. In Nigeria, sodium arsenite proved to be highly effective (72). In Malaya, both girdling and poisoning are widely practiced. However, some rather disastrous efiects to animals have been reported when sodium arsenite was used because of its high tox- icity (5). Its replacement by less toxic com- pounds will probably overcome these dii- ficulties. Especially large trees or those of certain 89 species are sometimes difficult to poison ef- fectively — Some species are inherently very resistant to poisoning while others have some peculiarity of bole form such as iluted trunk, strong high buttress, etc., that makes them almost impossible to kill easily. Jacob (55) reported that large Ficus trees recovered 1 year aiter poisoning even if they showed signs of distress. However, it is quite probable that some methods will eventually be developed to meet that challenge. Meanwhile, considerable improvement can be achieved by using the best poisoning tech- nique at the right time and under the most economical conditions. Barnard (22) after reviewing the poisoning methods used in the shelterwoed system in Nigeria concluded that many cumbersome operations were practiced and could well be replaced by more effective and cheaper methods. Instead of difficult climbing of trees with large buttresses in or- der to poison them above, he suggested frill -girdling and poisoning on the buttress itself at the most convenient height. Furthermore, this killing should be done during the rainy season and not at the peak of the dry season when growth is least active. Advantages and Disadvantages of Shelterwood Cutting over other Regeneration Methods Advantages 1. The regeneration is achieved without deviating too much from natural pro- cesses, especially as compared with the clearfelling method. 2. It is less often necessary to resort to planting than with other systems. 3. There seems to be less liability of at- tacks of insects and deseases. 4. The soil is always kept under some kind of a vegetative protective cover. 5. The system can be used with both toler- ant and relatively intolerant species. 6. The new crop develops good form during the initial years. The control of shade prevents the en- trance of undersirable pioneer species ~I 90 10. and to a certain extent, restrains the activity of climbers; fewer cleanings are needed. There is good protection against dam- aging atmospheric agencies. The system may be used with heavy seeded species. The system appears to be cheaper than any other. Disadvantages i. The system cannot be used with very intolerant species. Harvesting of valuable species may not always be possible because when only a few are present they are usually needed for seed source and once the re- generation is established, their removal through logging may be damaging to the new crop. This inconvenience be- comes particularly important when the second rotation eventually arrives. Evidently a large number of trees will have to be harvested this time. How- ever, it is quite possible that at that stage the forest will behave like the Dipterocarps earlier described; the lar- ge amount of good seed trees will then ensure a very good regeneration and logging can be done once the advance growth is established. These are, how- ever, merely guesses because this second rotation has nowhere been com- pleted in the tropics. It cannot be used in stands where seed trees of valuable species are absent or very rare. Dispersal of seeds by birds and bats may possibly counteract this fact but only to a small extent. The method requires some skill and good control over all operations involved. There are even some tolerant species that cannot be regenerated economical- ly under this method. This may be due to our present lack of knowledge of the silvics of these tropical species. CARIBBEAN FORESTER The Results so Far Achieved Reports from different countries where the shelterwood system is practiced are highly encouraging. Many improvements are con- stantly being made especially with the accu- mulation of more data on the silvics of va- rious species. In some areas, the shifting from other systems to shelterwood has been reported (70, 71). The recent introduction of silvicides is likely to increase the adoption of this system because their use finds ready application in many of the operations involvy- ed in shelterwood cuttings. The best proof of this is probably to be found in the fact that many countries, nota- bly Nigeria, Belgian Congo, Malaya, Trini- dad, and Costa Rica are expanding their programs of refining the heterogenous forest through this method. In tropical America, promising results have been obtained in Tri- nidad, British Guiana, and more recently im Costa Rica (53) where Astronium graveolens was regenerated, and Pert where Cedrelinga catenaeformis was the species involved (28). The results experienced in all these countries indicate that a bright future may be visual- ized for the shelterwood system. SUMMARY Regeneration methods in tropical lowland forests have lately received a great deal of at- tention. The present study intends to review and discuss the experience acquired so as to improve silvicultural programs for the future. In order to transform the heterogeneous forest with only a few valuable species into stands of better composition and_ higher values, three systems are currently practiced: 1. Clearcutting followed by immediate planting of valuable species. It can be done satisfactorily only with light de- manding, fast growing, naturally in- sect and disease resistant species, on accessible lands and on _ ecologically suitable sites. The best utilization of JULY - DECEMBER 1956 91 the forest to be cleared and the tem- much modified, when seed trees are porary use of the soil for agriculture present in adequate quantities and (‘‘taungya” system) appear econom- when rather tolerant species are to be ically very desirable, but require a regenerated. good control over all operations in- The usual operations involved in securing volved. a good reproduction require opening oi the 2. The artificial enrichment of the forest stand particularly at its intermediate levels by underplanting in strips. Best re- (see cuttings) and the final complete removal sults have been achieved in secondary of the canopy at a later stage. forests close to settlements. Broadcast seeding on abandoned lumber roads, shortly after the beginning of the rainy season, as practiced in Yucatan, Mé- xico, appears a promising alternative. 3. The shelterwood system. It has been used most successfully when the original The system is favored by an increasing structure of the forest has not been number of tropical silviculturists. Girdling and poisoning of undersirable species appear to be very effective practices to complement harvesting and the gradual elimination of the canopy and favor the best development of the new growth. 92 CARIBBEAN FORESTER Report of an Ecological Survey of the Republic of Panama L. R. HOLDRIGE, Forester and Ecologist GERARDO BUDOWSKI, Forester Interamerican Institute of Agricultural Sciences Costa Rica INTRODUCTION In response to a request from the Govern- ment of the Republic of Panama directed to the Technical Cooperation Program of the Organization of American States, an ecological reconnaissance of all Panama was made in the Spring of 1955. Considering the size of Panama and the fact that the two technicians had only one month available for the work, mapping was restricted to de- lineation of the life zones of forest forma- tions of the country. However, this was the goal of the project and the following notes describe these areas and their relation to agricultural and forestry uses. Such an ecological survey is considered to be one of the basic steps in planning national uses of a nation’s resources. At the same time an attempt was made to sketch out the most promising areas for concentration of extension work, future sur- veys and forestry development. The ex- periences, both favorable and unfavorable, of other countries of the region in utilization of the renewable resources in the various life zones have been drawn upon as a guide for Panama, where the population is still of hight density. In order to develop and maintain a satis- factory level of living, man must maintain an ecological balance with his environment. If he works in harmony with natural con- ditions, he can develop an efficient and per- manent use of renewable resources which will provide him with all the necessary bene- fits of an abundant life. If he work against nature, the results will be a waste of re- sources, giving rise to poverty and many economic and social problems. Fortunately, Panama is still in a favorable position to guide its own development and, if it, so wishes, may develop a strong, sound economy and a strong nation. Before going on to further discussions, we wish to express our sincere appreciation to the many organizations and individuals who so willingly cooperated in many ways to facilitate our work. The organization of SICAP, directed by Mr. Benjamin Birdsall, made the arrangements for all trips within the country and provided for transportation and other expenses of the survey. Dr. Solis and Mr. Lawrence Cummings of SICAP took care of specific trip arrangements and the latter accompanied us on most of the trips. Mr. Guzman and other in the main office assisted us in collection of data and SICAP agents in the field helped us a great deal on local arrangements. The Chiriqui land Co kindly furnished motor car transport in Chiriqui Province. Also Mr. Max Arosemena and his organiza- tion, Instituto de Fomento Econdémico were extremely helpful in arranging trips just to the east of Panama City. Diputado Pa- blo Oten of Darién helped us very much in the region of El Real. To all these and the many other individuals two numerous to mention, we wish to express our apprecia- tion for their assitance in making our sur- veys more efficient and pleasant. General Geographical Facts of Panama The Republic of Panama comprises the southeastern extension of what is generally JULY - DECEMBER 1956 considered as Central America, bounding with Colombia on the East, Costa Rica on the West and with the Atlantic and Pacific Oceans respectively on its northern and southern coasts. The area of the territory is 29,128 square miles excluding the 553 squares miles of the Canal Zone. The popu- lation of the country was listed as 851,900 in 1952, constituting a density of only 29 percent inhabitants per square mile. In snape, Panama essentially resembies an irregular and narrow arch, running in a general east-west direction, and varying in width from 30 to about 120 miles. The same orientation applies to the main moun- tain range which form the backbone of the country with only one appreciable gap in the center in the vicinity of the Panama Canal. This range reaches a height of a little over 11,000 feet in Volcan Chiriqui or Bara at the western end, but elevations are much less to the east of the Canal. Other minor mountain ranges occur in the Peninsula de Azuero to the South, along the Colombian frontier and bordering the Paci- fic coast in eastern Darién Province. Due to the many mountains on such a narrow trip of territory, there is little left for the plains. The largest of these are found on the Pacific side, both in Darién Province, where the biggest rivers occur and in the provinces of Chiriqui, Veraguas, Co- clé and Los Santos on the western sides of the country. Climatic Factors Temperature The Republic of Panama lies wholly within the tropical belt so that all of the lowlands have a mean annual temperature of over 24° centigrade. The highest temperatures oc- cur in the drier areas on the Pacific side of the country. With increasing altitude, lower tempera- tures are encountered, which give rise to four significant elevational belts of vegetation. The lowest of these is the tropical belt, rang- 93 ing from sea-level up to about 600 meters on the Caribbean slopes and up to approximate- ly 700 meters on the Pacific slopes. The subtropical belt extends from these elevations on up to approximately 1,500 me- ters above sea-level. The lower montane belt extends from the upper limit of the subtrop- ical belt up to aproximately 2,600 meters above sea level. The major part of this belt is restricted to western Panama in the Cor- dillera de Talamanca and the Serrania de Tabasara but small areas do occur in eastern Panama along the frontier with Colombia. The montane belt is restricted to a few iso- lated areas on the higher peaks in the Tala- manca Range. Although a few subalpine plants may be found on the peak of Volcan Chiriqui, Panama does not reach the subal- pine belt. The approximate total acreages and per- centages of the area of the country by ele- vational belts is shown in the following table: ‘ Total Percent Area in K2 of area Tropical Basal Belt 56,430 76.3 Subtropical Belt 13,800 18.6 Lower Montane Belt 3,530 4.8 Montane Belt 250 0.3 Total 74,010 100.0 Precipitation Within the elevational belts, differences in annual rainfall give rise to significant changes in natural vegetation and corre- spondingly in agriculture. These natural di- visions which are termed life zones or plant formations are plotted on the map of Pana- ma on page 94. Ordinarily, the transition zones where two formations join are not extensive and one line delineates the change from one life zone to another. However, in the Darién region, we found that the total precipitation over considerable areas is very close to 2,000 mm. or 80 inches and the change in pre- cipitation is so gradual that the zones of 94 transition are extensive enough to warrant separate delineation. The rainfall on the Caribbean coast and slopes follows the general pattern of the Ca- ribbean area. The trade winds from the northeast and east bring air which is heavily laden with moisture to the land and precipi- tation is essentially orographic. Heaviest an- nual precipitation probably occurs in the low- er part of the lower montane belt or the up- per part of the subtropical belt, at around 1,500 m. elevation. At present, however, there are no meteorological stations at these elevations on the Caribbean slopes to verify this statement. The air movement from the Caribbean pas. ses to a limited extent over the divide dur- ing the rainy season so that the upper parts of the southern and southwestern slopes are definitely influenced by the Caribbean cli- matic regime. Only in the vicinity of the Ca- nal Zone, where the country is generally low does this Caribbean influence during the wet season extend across the isthmus to the Pacific. This is evident just to the west of the canal and may be observed in the vege- tation along the highway from before Cho- rrera to beyond Capira. On the Pacific side, the precipitation is predominantly conventional, occurring during the rainy season when the belt of dol- drums has moved north from South America to over Panama. However, there appears to be a strong influence there of winds from the southwest so that wherever parts of the isthmus face the southwest, there is an in- dication of higher rainfall giving rise to a yegetation similar to that of the Caribbean side. In general then, the whole Caribbean side is moist to wet whereas the Pacific side is broken into moist or dry subregions. The dry season is long and strong in the dry for- est formation on the Pacific. Also, the dry season is more marked in the moist forest formation there than in the corresponding life zone on the Caribbean side. CARIBBEAN FORESTER The driest area observed in Panama was found on the western side of the Azuero Peninsula. Cicse to the Colombian border, there is in- dication of entrance into a different climatic region which is generally more rainy, and thus, wind directions and mountain barriers do not seem to be as important in influenc- ing rainfall as they are to the west. Winds Winds are significant to the Panamanian climate mainly in producing orographic rain- fall and accentuating dryness cn parts of the Pacific slope, when the stronger trade winds cross the isthmus during the dry season. Fortunately, Panama lies out of the sweep of the hurricanes which cross the Caribbean sea to the north. However, in connection with storms, local wind currents may cause “blow- downs” which can affect seriously such crops as bananas. Edaphic Factors Although the climatic factors of tempera- ture and precipitation determine the pattern of life zones or formations, within each for- mation, the plant associations, the physiog- nomy or appearance of the vegetation and the best use which man can make of the areas depend upon the edaphic or soil fac- tors. These factors comprise topography, water table levels, physical condition and chemical composition of the soil. Topography Panama is predominantly a country of low and medium elevation. Only in the western part of the country are to be found appre- ciable areas in the lower montane and mon- tane belts. As a continuation of the high mountain range of Costa Rica, the Cordillera de Talamanca and the Serrania de Tabasara occur as a high broken mountain range, which attains its highest elevation at 3,470 m. in Volcan Chiriqui. Most of the subtropical belt comprises rough topography with only very limited areas of flat or gently sloping lands located in the valleys or on the tops of wider ridges. 56 JULY - DECEMBER 19 punudg fo oqnday - auoz uolnpUdo] JUD] Ban 1S3Y¥O4 LIM JINVLNOW (@) oO a 1S3404 13M 3NVLNOW 43M07 [ Se 2s Oo i fea 153404 LIM WOIdONLENS re = ss x I . ® Tp , 1S34Od LSIOW WOIdONLENS D eaten, ON3999 OO) ni +4, \) ~ E ra ERRAND ay) VWVNVd 40 DINE Nd SY BA i KK (XX FARRER ORAK ORES 5B RAXAAAAX RRR BAG PRR RK KC WRK RX ORCC q RPA RXK RXR KK RRR KX D ae WH MUUKUninnnnniiatine BLK RXR SA LY IPRA WORRY Se NOUN a as ern itt % ELLERY YS ty BT BKKK FR RRR RRL PASS a —— een naidiniiit BA Lecex x KIA X CK KKK KKK KKK KK XE ROO OO OOO AN ROS SOK» RG KKK KKK HK CRE RY RRR KR 200039 00001 200 10X20 indrnninniets OK) DO OK SY ENN xX XXX X, > XK KPQOOO IKK X x pn x N = x ba X foo £\ HAR XK KK KKH HH x OPO E = ¥ a RX Th ee et PKR ORK KARI = ——— = ‘ RRA LON = — oO RRR ARR XXARA AAD ae e) RRR RA RX AKERRY RAD = ———= RIAA RK AR RAX RAL RRA ANY SAE, Ww REALE RRX RQ AREAL PALO? FSR 0 OOOO) NRE A RK KKK KX RAMA NYY = = =i asurnnnnnnnnnniininnniite ents : — BRR RR LK KR RAY =p Db X PRIA RNROX —— PERRET RNR KCC —$——— = EN, One, C pe) x RY Ra (NOILISNVYL) LSINOF LSIOW WOIdOUL : = (@) Dp 1S3IYOd LSIOW TWOIdOUNL : [ S| SS XXX XX XXXKXX pox (NOILISNVYL) LSIHOd ANG WOIdOYL xX | l| | 1S34O4d ANA TWOIdONL ON3939) EEE 96 Also, the lower tropical belt which covers the major part of Panama is predominantly hilly and broken. Within the area of moist forest on the Caribbean side there are nu- merous narrow alluvial strips along the riv- ers, but only in the Bocas del Toro Province and in the area just to the west of the Ca- nal, as between Chorrera and Gatun Lake, are there extensive areas of flat or gently sloping lands. On the Pacific side four significantly im- portant areas of level and gently sloping lands are to be found in the David — Armue- lles section, the Coclé-Veraguas-Herrera dry forest areas, a strip running east from Pa- nama City with a narrower extension up the Rio Bayano Valley and lastly, the river val- ley areas of Darién Province. High Water Tables and Excessive Drainage Wherever water tables are high during part or all of the year, the vegetation of such areas is quite distinct from that of adjacent normally drained forest lands. The most ex- tensive of such areas are to be found in the lower river valleys in Darién Province and adjacent to the lagunas in Bocas del Toro Province. Similar associations of limited areas are to be found also along the rivers and coasts in many parts of the country. Of much less total acreage are the areas of sandy soils and limestune hills where drainage is excessive as reflected in a less luxuriant and’ more xerophytic vegetation. Examples of such areas may be observed around Patino in the Darién, on the hills south of Conchita on the Bayano River, and on some of the voleanic cutwash areas in Chiriqui Province. There is still another combination where a hard-pan results in waterlogging during the wet-season and excessive drying out dur- ing the dry season, as may be seen in the flat savannas of the Coclé region. However, the savanna areas are also complicated with chemical poverty of the soil which may be CARIBBEAN FORESTER due in part to their original composition and in part to long-continued, annual burning. Physical and Chemical Conditions Aithough it is general knowledge, that the physical and chemical conditions of the soil under virgin forest cover may be quite sat- isfactory or excellent, of special importance to man in relation to his agriculture are those areas which can maintain such conditions for long periods of time following re- moval of the forest. The areas which come closest to fulfilling these requirements in Panama are the flat alluvial lands and the areas of recent volcanic soils. Such recent volcanic soils in Panama are to be found on- ly in extreme western Panama. There, where flat alluvial lands have been enriched with recent volcanic soil, are located the best agri- cultural soils of the country. Still there are extensive areas of alluvial soil in other por- tions of Panama which can adequately sup- ply the agricultural needs of the country for some time to come. Stony soils are common in the dry area of Chiriqui Province and extensive areas of low fertility in the dry forest formation are to be found in the vicinity of David, in Coclé and Veraguas and to the east of the Canal. In the moist forest formation, a smaller area of very poor soils giving rise to savanna vege- tation may be observed between Chorre- ra and the coast. Biotic Factors Aithough, ecologists consider under this title the effect of all forms of life on the vege- tation, in the present discussion, we will restrict consideration essentially to the ma- jor influence of man, together with that of his domestic animals, and of fire which is almost exclusively spread by man. With a quick glance at the map one can observe the apparent concentration of place names in the tropical dry forest life zone. These were the major areas of settlement in the centuries following the first European colonization of Panama and very likely had constituted previously the main centers of JULY - DECEMBER 1956 aboriginal settlement based on maize culture. This was primarily due to the lesser effort needed to control woody vegetation which competed with cultivated crops or, subse- quent to Spanish colonization also with the grasslands established for pasturing livestock. Long continued burning in these dry regions has greatly altered the original forest vege- tation and has been conducive to much impo- verishment of the soils, especially on the hilly lands. Within the past century, three other con- centrations of population have been devel- oped, one within and adjacent to the Canal Zone traversing the isthmus and the other two connected with banana culture in Bocas del Toro Province and in the Comarca del Baru. From these various centers of population concentration in both life zones, the expand- ing population is now moving out into adja- cent areas. Man’s influence in the rest of the Republic is much lighter and tends to date to be confined to narrow strips along the coast, along the rivers and along the high- ways which have been developed in recent years. In general, the overall influence of man on the vegetation of Panama is still quite limited and restricted to certain areas of concentration. Within these, the areas af- fected by crop cultivation are much less than those where the vegetation has been cleared by man or fire for grazing. However, the population has now reached numbers where subsequent geometric in- crease are bound to result in profound changes of the vegetation and natural land- scapes of Panama within the next few gener- ations. The need for planning and the pos- sible results of man’s future impact on the natural resources of Panama are discussed subsequently in the report. Natural Vegetation of Panama The natural vegetation of any area is a response to the climatic and edaphic factors prevailing on the site. Within a biogeogra- phical province, many species of plants may be used as indicators of variations in climate 97 cr soils. This is especially important in Pa- nama where meteorological data is scant and the soils have been little studied. In the pre- sent study, observations were confined large- ly to tree species, which because of their size and major exposure to the climatic ele- ments are considered the best indicators. Where man has made extensive clearings, however, it was found necessary to use smaller elements of the vegetation also, in addition to any scattered trees. Since this survey was an ecological recon- naissance and time was extremely limited, few collections were made and there was no attempt made to identify all of the tree ele- ments of any given association. Tree lists in Many areas were compiled with the main purpose of locating the indicator trees which are of special importance in classifying an area and which permit interpretation not on- ly of climatic and edaphic factors but also of present and potent’al agricultural use. The tropical dry forest of Panama is cha- racterized by the following trees: Acrocomia sclerocarpa Mart., Palma paco- ra o Corozo Albizzia caribaea Apeiba tibourbou Aubl. Cortezo Bombacopsis quinatum (Jacq.) Cedro espino Bumelia sp. Pino alegre (?) Calycophyllum candidissimum (Vahl) DC. Madranio Chlorophora tinctoria (L) Gaud. Mora Cochlospermum vitifolium (Willd.) Spreng. Poroporo Diphysa robinioides Benth. Macano Dugand Enterolobium cyclocarpum (Jacq.) Gris. Corotu. Luehea candida (?) (DC.) Mart. Pithecolobium saman (Jacq.) Benth Platimiscium pinnatum (Jacq.) Dugand. Quira. Prosopis juliflora (Sw.) DC. Aromo Pseudosamanea guachapele (H.B.K.) Harms Sciadodendron excelsum Gris. Lagarto Simarouba glauca DC. 98 Sterculia apetala (Jacq.) Karst. Panama Sweetia panamensis Beth Tabebuia chrysantha Guayacan Xylopia frutescens Aubl. Malagueto macho There are nearly 100 species of trees of al! sizes in the association on good soils. Also, we are not listing here many striking trees such as Ceiba pentandra Gaertn., ceiba; Bur- sera simarouba (L.) Sarg., carate; and Didy- mopanax morototoni (Aubl.) D. & P. because such species are found also in the Tropical Moist Forest. On the poorer soils, such as the savanna lands of the Pacific side, the number of spe- cies are less, the original forests were compos- ed of trees of lower stature, there are more spiny legumes such as Prosopis juliflora (Sw.) DC and Acacia farnesiana Willd., and we find, in places, high percentages of fire-resistant species which tolerate poor soils such as Cu- ratella americana L. and Xylopia frutescens Aubl. The two associations of poor soils in this life zone are to be found in extensive areas as exemplified in the savannas and the low foothills of Coclé province and around Da- vid in the province of Chiriqui. Along streams or on alluvial flats next to rivers where the water table is high, may be found tree species from the tropical moist forest such as Anacardium excelsum (Bert. & Balb.) Skeels, espavé, but these are not able to resist the long drought on the sloping lands. The above four mentioned dry land asso- cations are the main grouping of plants cov- ering appreciable areas. There are small- area plant associations of scientific interest, but these were not considered of importance in this study. The swamp forests are to be treated in a subsequent part of the report. The Tropical Moist Ferest The Tropical Moist Forest including the transition zone to the dry forest covers ap- proximately one half of the area of Panama. CARIBBEAN FORESTER We were not able to separate out the West Forest although there are indications along the San Blas coast and farther west that pos- sibly considerable areas may have a rainfall of over 160 inches and belong properly to another formation. However, travel within the Caribbean coastal forest strip is difficult and time did not permit our making exten- sive trips into the foothills. The characteristic tree species of the Tro- pical Moist Forest are listed here as -follows: Anacardium excelsum (Bert. & Balb.) Skeels Espavé Brosimum spp. Carapa guianensis Aubl. Cecropia obtusifolia Cenirolobium patinense (?) Pittier Coccoloba (?) tuerckheimii D. Sm. Couroupita panamensis Dipteryx panamensis Gustavia sp., Membrillo Iriartea exorrhiza Mart. Jacaranda copaia (Aubl.) D. Don, Palo de buba Lecythis sp. Coco Luehea seemannii Tr. & Pl., Guacimo Pentaclethra macroloba (Willd.) Kuntze Theobroma purpureum Pittier, cacao ci- marron Virola spp. Warscewiczia coccinea (Vahl) K. Transition Forests Ordinarily transition areas between two life zones are narrow and are not mapped sepa- rately, but in Darién Province we found such extensive zones of transition that we mapped these out separately. In such trans- ition areas, there is a mixture of the tree species from each formation plus certain species which are typically transition species. The interesting tree, cuipo, Cavanillesia platanifolia H.B.K. is one of the latter. When one crosses the isthmus of Panama near the Zone, this huge tree is found fairly well re- stricted to the edges of the moist and dry JULY - DECEMBER 1956 forest in a narrow strip. However, in the Da- rién, this species occurs over a very Wide sec- tion indicating clearly that this whole area is a transition belt. The portion of the moist forest which is typed as transition forest contains a much higher percentage of valuable timber species than is ordinarilly found in the moist forest, climatic conditions are also excellent for agri- cultural use. Swamp Forests The swamp forests of Panama are exten- sive and especially interesting for potentiai forest industries because of their composition of one or few species. Such pure stands are rare in the tropics except under special eda- phic conditions. Of the various associations the four which are most extensive are the manglares, the alcornoque forests, the cativo forests and the orey forests. Although there are swamp forests of va- rious sizes scattered all along the coasts of the republic, we carried out the major part of our observations in the Darién and in Bo- cas del Toro Province, where these associa- tions comprise thousands of hectares. Al- though the rainfall is considerably higher at Bocas del Toro, the major difference between these areas is the fluctuation in tide levels. On the Caribbean side there is a difference of a litttle over 20 inches between mean high and mean low tide levels whereas in Da- rién this difference is close to 20 feet. With this differential in tide levels in the Darién, the effect of the tide are felt far up the rivers, although there the rise of water is due to the damming of the waters by the tide. The approximate point on a river to which the brackish waters reach appears to be marked by the disappearance of red man- grove (Rhizophora mangle L.) and the ap- pearance of Montrichardia arborescens (L.) Scholt, a tall aroid, which grows on the soft mud of the river banks. The most extensive flooding occurs when the highest tides co- incide with periods of heavy rainfall and fuil rivers. 99 Mangrove Swamps In Darién Province, there are several thousand hectares of periodically innundated tidal swamps occupied by pure stands of red mangrove. With the high tides, the salt water moves back readily through the forest which probably accounts for the extensiveness of the red mangrove. At Bocas del Toro, the red mangrove is found on the fringe of the swamp only with black and white mangrove occupying the area towards dry land. In the Darién, these species show up first on the river banks where fresh water from the rivers reduce the salinity. The stands of red mangrove appear to aver- age around 80 to 90 feet in height with good straight boles and heavy volumes per acre. At the present, they are exploited only for the bark of the tree and this cutting has not been very extensive. Aicornoque Swamp Forests Again in the Darién Province, this associa- tion covers extensive areas, apparently taking over the area of manglares which have been built up to a higher level. Here there is more firm ground which appears to be above nor- mal tide levels, but which when flooded is covered with brackish water. The trees run to larger diameters than the red mangrove and are not as tall or as straight. They do in total, however, contain a large quantity of timber in pure one-species stands. Pterocarpus officinalis Jacq. | Stands This leguminous tree with ribbon buttresses occasionally form pure stands just next to the mangroves in perhaps softer lands and those more inundated with brackish water than the alcornoque forests. At any rate, they are nowhere extensive in Panamé and are not important as commercial forests. Orey Swamp Forests In Bocas del Toro Province, nearly pure stands of Orey, Campnosperma panamensis Standl. occur extensively on the low lands, 100 Fig. 1-Dense stands of red mangrove (Rhizophora mangle L.) in Panama, reach an average height of 24-27 meters and trunk diameters sometimes above 40 centimeters. CARIBBEAN FORESTER just above sea-level, of the islands, peninsulas and mainland shores. It appears, that these areas are not actually flooded by the tides but that there is a high water table of brack- ish water. The asociation contains a few other small trees in the understory and an occasional large tree of Symphonia globulifera L. in or above the canopy. The stand is not tco heavy in volume as the trees are mostly in the 10 to 18 inch diameter range and the trees do not appear to go much beyond 60 feet in height. Cativo Forests On the flat lands of the Darién extensive areas are found of nearly pure stands of ca- tivo (Prioria copaifera Gris.). This tree seems to occur on flats above normal tide levels sim- ilar to those of alcornoque, but when inun- dated are covered with fresh water only. A few other species such as tangare. (Carapa guianensis Aubl.) and Quararibaea are mixed with the cativo even where the floods are highest and as the land becomes progressive- ly higher more and more of the species of the normal tropical moist forest appear in the mixture. Fig. 2. - Dense and valuable stands of cativo (Prioria copaifera) are found in the forests along the rivers of Darién. JULY - DECEMBER 1956 These stands, as described by Lamb, contain heavy volumes per unit area as the cativo is a tall, straight tree of large diameters and occurs in dense stands. Pachira aquatica Aubl. Swamp Forest Above the alcornoque forests on the Sam- 101 ba River, we observed small areas of pure stands of this tree. The association seems to be restricied to soft, unstable soils which are flooded by fresh water only. This associa- tion probably fills the role of stabilizing such soils, and then, is replaced by cativo. The trees in the stand are less than 30 feet tall Fig. 3.- Interior of a mora forest (probably Mora excelsa:) in the lower banks of the rivers in Darién. Although the stands have a high volume per unit of area the trees seldom are well formed. Fig. 4. - Interior view of a stand of Pterocarpus officinalis, often flooded. The trees are rather of small diameter but have large and thin buttresses. 102 with diameters below 8 inches. The associa- tion is of no importance for timber. Manicaria Swamps In Bocas del Toro Province, we observed fresh water palm swamps which are found also farther west along the Caribbean coast. The Manicaria is a large-leaved and short- boled palm. No observations were made within these swamps but in some places it was noted that cedro macho reproduction was beginning to grow up above the palms. Subtrepical Forests Little time was spent in observations of the vegetation of this belt above the lowland tropics, primarily because they are of much less economic importance than the lowland forests. Where rainfall is high they are, how- ever, extremely important for the regulation of stream flow. Where near to center of pop- ulation, they attain special importance for park, recreational, or vacation home and hotel areas. The subtropical moist forest is typified pri- marily by several species of the Myrtaceae of both the genera Eugenia and Myrcia. In gen- eral, the association is composed of small- leaved species and the natural forests is of little importance for timber. Within this life zone, most of the criginal forest has been re- moved for the planting of coffee or other crops. The subtropical wet forest is a higher dens- er forest with many Rubiaceae, Melastoma- ceae, and Lauraceae, Laplacea, Brunellia, Inga spp., Calopkyllum, Taonabo, Ouratea, etc. In the Cerro Azul district, we travelled beyond Loma Pelado where the vegetation approaches that of Subtropical Rain Forest. Here was found Podocarpus, Alfaroa and Quercus. As indicated by the tops of the hills, where the vegetation is low and sparse, leaching of the soils due to the high rainfall is very pronounced. Once the higher natural forest is removed on the slopes, the same CARIBBEAN FORESTER process of deterioration of the soils will take place. Thus the natural vegetation indicates very clearly that this area is not suited for agriculture. The lower montane forest of the Chiriqui mountains is characterized by Persea schie- deana Nees, Quercus copeyensis, Weinmannia pinnata L. and Cedrela tonduzii. There are several timber species, the trees of large di- mensions and the stands heavy. The area makes excellent pasture with kikuyu grass (Pennisetum clandestinum Choiv.) but most of the area in this formation is really too steep for agriculture. Both this and the montane forest above, which we did not visit, are im- portant for the regulation of mountain streams. Future Use of Resources As mentioned previously, the present pop- ulation of nearly one million people have made as yet only light inroads on the natural resources of the Republic. This is even more marked in Panama where a_ considerable number of people near the Canal Zone derive their income from service and trade opera- tions which do not draw upon the resources of the Republic. However, the doubling, redoubling and re- doubling of the population which will occur within the next century is bound to bring forth tremendous changes and a terrific im- pact on the natural resources of Panama. It must be a sobering thought to government leaders to note that with the present ple- thoria of natural resources, namely, rich lands, excess of valuable timbers, abundant water and wild life that so many families ac- tually continue to exist on a low subsistence level only. Such low level subsistence agri- culture destroys potential riches without any benefit to a nation and seems to result only in a rapidly increasing number of additional family units to carry out further destruction on a faster and more extensive scale. Undoubt- edly, the people of Panama and their leaders are faced with a very serious challenge in the use of their available resources. The pattern JULY - DECEMBER 1956 of use within the next few decades will deter- mine whether they are to live a rich, happy life in harmony with their environment or to waste their natural wealth and develop an- other tropical ‘‘poor-house”’ of low-level subsis- tence only. Thus, Panama is faced with two distinct yet related problems, namely, that of raising the existing levels of living of the present pop- ulation and that of planning future use to maintain and improve on any immediate gains and with a continually increasing pop- ulation growth. To do that, the people of Panama must understand thoroughly their re- newable resources and how to use them in a manner which will sustain or improve their productivity. Of the basic resources, the soil which di- rectly or indirectly gives sustenance to plant or animal life, is the most important, Panama has sufficient level or gently sloping lands of the proper physical and chemical nature to produce the agricultural products for its own requirements and with an appreciable surplus for export, and do this on a sustained yield basis for many times its present population. All agricultural efforts of the present should be concentrated on such lands. Improve- ments in crops and agricultural techniques to raise production to a much higher level are possible and have been demonstrated already in limited areas. On the other hand, clearing of new land for agriculture should not be allowed to pro- gress into areas of rough topography or low fertility, as such terrain can not support a stable, high level agriculture. This leads to undesirable future socio-economic problems and also, in many cases, through alteration of stream flow and erosion, jeopardizes the permanent high-quality agricultural lands below with the threat of floods or scarcity of water for irrigation. Furthermore, the origin- al area, before despoilation, may have had a much higher potential value for other uses such as timber production or recreation, over and above the values of stream regulation and protection for wild life. 103 Specific examples of what should be stimu- lated and what should be avoided can easily be found in Panama. Some of the rice plan- tations along the railroad between David and Concepcién in Chiriqui Province with their high degree of mechanization demonstrate very well that man can produce surplus food effectively by using the right methods in the right areas. Again in the same general re- gion, the banana plantations near Armuelles demonstrate the tremendous productivity possible by good land use and the employ- ment of advanced techniques. The Chinese vegetable growers near the Canal Zone de- monstrate clearly what can be accomplished with intensive management and careful main- tenance of the soils. On the opposite side of the scales, numer- ous examples of misdirected effort could be cited which are detrimental or represent eco- nomic losses to the nation. The felling and burning of magnificent stands of previous woods on the hills in Darién Province for the production of one or two crops of grains is a good example of waste of natural resour- ces and economic loss to the nation. In the Cerro Azul area, only a few miles by car from Panama City, the hills rise up into the cool air of the subtropical belt. Here there are picturesque forests and magnificent views of the surrounding lowland to and be- yond Panama City a swell as of the coast and the Pacific Ocean. This whole area of the subtropics so close to the capital city has an inestimable value for recreation and rest as it offers the possibility to get away rapidly from the heat and noise of the city. The en- tire section should be zoned for future vaca- tion home sites and public parks. On the con- trary with the arrival of roads in the locality there is actually a growing attempt to devel- op the area egriculturally with coffee plan- tations and grazing which at the same time will detract from the recreational value of the area. This is a clear case of the lack of long term planning and unwise land use, as in addition to the fact of the high value for recreation the vegetation indicates that the 104 area is not suitable for long term, profitable agriculture. Considerable survey work and study of the area of low-fertility soils in Coclé and south- western Panama Provinces which offer little possibility for economic improvement have been carried on recently. It would appear that in light of the limited number of soil technicians available that efforts should be concentrated first on the areas of potentially highly productive soils such as those to the south and southwest of Concepcién in Chiri- qui Province or on some at the other lowland areas mentioned previously. The fertile lowlands with their inherent richness and adaptability to mechanization offer not only high productivity per man and hence potential high levels of living for the agriculturist, but also the best possibilities for advancement in crop improvements anc agricultural techniques. Such agricultura: zones can develop and support good s1oad systems, advanced educational systems, g00d housing and high health standards. Through their high productivity per unit area and per man, such agricultural lands can play a very important role in reducing pressure on sub- marginal lands and in freeing a percentage of the labor force of the nation for develop- ment of industrialization. Development of wet land rice cultivation should be consid- ered, because of its high productivity per unit area. Similarly to crop production a grazing in- dustry which is based on the use of extensive areas of poor land with run-of-the-mill stock and cheap labor can provide excellent profits for a few families of large land-holders, but contributes very little towards the raising of the general level of living or to the pros- perity of a nation. Sound development must be based on intensive land use of suitable areas with concerted efforts to improve the herds and the pastures. Examples do exist in Panama of such progressive farms showing that such developments are possible and prof- itable. Such intensification must be stepped up to prevent further expansion of the industry CARIBBEAN FORESTER into areas which are not suitable and are truly submarginal for grazing. Even though as pointed out previously, such lands may produce profits for one family this is brought about at the cost of a low, unsatisfactory level of living for several families of laborers, a status not conducive to general prosperity and strengthening of the nation. The present assignment of fertile flat lands to either cultivation or grazing is still largely based on the personal preferences of the owner. Further technical advances in these fields should lead to a more economically de- sirable assignment of lands to their optimum use. There seems to be a healthy adjustment taking place now in this respect as, for exam- ple, may be observed to the east of Panama City towards Chepo where flat, easily mecha- — nized portions of previously grazed lands are being segregated and utilized for crop pro- duction. Aside from economic and market condi- tions which have their particular importance on crop selection, the distribution and acre- age available of high quality soils should be considered in the light of the life zones or formations. As an example of this the sub- trupical moist forest represents the ideal cli- mate for Coffea arabica L. but the plant will produce well also on recent volcanic soils of the Subtropical Wet Forest. In Panama, the acreage available for expanding coffee cul- ture appears quite limited. As a matter of fact, coifee is being spread in Panama both beyond its climatic limits and into soils which will not be highly productive. The inversion of capital in a crop away from optimum con- ditions tends to handicap general progress. In the first place such capital is diverted away from more productive investments and second, such landholders are prone to oppose the raises in wage and living levels of agricul- tural laborers which would automatically bankrupt their submarginal operations. Since cacao is an excellent crop for the tropical moist forest and large areas of rich alluvial soils are available within that life JULY - DECEMBER 1956 zone for the expansion of this crop, invest- ments in cacao plantations, as opposed to coffee appear much more desirable for Pana- ma. Also, as recent investigations have de- monstrated, cacao, offers many opportunities for technical improvement of present cultiva- tion practices. In general, until much more investigation has been carried out on management of tropi- cal soils and agricultural techniques, it is safer to follow the indications of the natural vegetation and avoid attempts to produce crops where more than normal problems will arise. The tropical moist forest is essentially a tree climate and best results are to be ex- pected with crops such as cacao, bananas, plantains, rubber, oil palms, abaca and the like. In the tropical dry forest formation, field cropping of grains and maintenance of grasslands for pasture is much simpler. Wi- thin this life zone in Panama are to be found the best conditions for producing upland rice, corn, cotton, sugar-cane, ajonjoli, beef cattle and tropical fruits such as mangos, avocados, nisperos, caimitos, etc. Where flat, fertile lands can be irrigated, production pos- sibilities are very favorable. The mountain formations, with the excep- tion of level or gently sloping valley lands, should be permanently reserved in forest. in the very near future, Panama should close up such mountainous areas to agricultural expan: sion and assign the reservations as national forests. Subsequently, these reserves can be studied and divided up into the classifica- tions of production forests, national parks, wilderness areas, etc. according to their high- est use. The reservation at this time would be politically easy but if reservation is post- poned until many people have moved into the areas as colonists, many additional prob- lems will be confronted. As pointed out previously, such areas can uot support permanent agricultural settle- ments with a satisfactory level of living, so that their closure to agriculture in that re- spect is on the best interests of the nation. Furthermore, the maintenance of such lands _ to disease. 105 in forest guarantees protection from disastrous floods and assures adequate supplies of water for irrigation and hydroelectric power devel- opment, thus insuring stability for the ughly productive agricultural zones below. Subsequently, they become increasingly more smportant for recreational use and timber production. Darién The province of Darién is considered suf- ficiently distinct and so lightly affected by man to date as to warrant separate treat- ment in this report. As may be noted on the map the greater part of the lowland areas fall in the tropical moist forest formation, but the annual rainfall averages are so close io the approximately 80 inch line of division with the dry forest that we have mapped a large portion as a distinct transition zone. Around the Ensenada de Garachiné and in the upper reaches of the Rios Sabana and Chucunaque is found dry forest of a transi- tional nature also, even though on areas of sandy soil and coral limestone outcroppings in the former district, the vegetation appears at first glance to indicate still lower rainfail. Along the Pacific coast to the south and towards the Colombian border and San Blas, rainfall increases to give rise to typical moist forest and with increasing elevations consid- erable areas oi the subtropical wet forest and small areas of lower montane wet forest are encountered. The present population of Darién is scat- tered in a few towns or settlements on the coast, the estuaries or the rivers with agri- cultural development on the fertile alluvial lands close to water transport. Bananas and plantains appear to be the main commercial crops of the agriculturists, the latter often following bananas which are more susceptible The main industry of the region is that of logging, with logs of precious woods cut for export to Central Panama and out- side and with some milling of lumber of va- rious species carried on within the province. Because of the relatively light influence of 106 man to date in the province, Darién offers excellent possibilities for careful planning of the future utilization of its resources. The five most significant facts to be consid- ered in the planning of Darién, are as fol- lows: (1) the great differential between low and high tides, (2) the rich alluvial or gently sloping lands between mean high tide level and hilly country, (3) the tide or swamp forests over extensive areas with homoge- nous stands of one or a few species, (4) the enormous potential timber value in the dry land forests where so many precious woods are to be found and, (5), the extensive sys- tem of natural navigable waterways running through this wealth of resources. Sea-going steamers can enter the estuary of the Rio Sabana and up the Rio Tuira to Chepigana. In addition, the strong tides extend their influence far up the rivers for the benefit of smaller embarcations. Agricultural development of the region on any large scale is potentially both promising and precarious. The most promising areas at the moment are those alluvial or very gently sloping lands back from the water- ways towards the hills where the flood waters from a combination of high tides and full rivers in the rainy season do not reach or significantly affect the terrain. These areas are very little used at present because they are away from current river transportation. Between these areas and mean high tide level occurs a much more extensive zone of level terrain and fertile alluvial soils which offer the greatest promise for agriculture if effective flood control measures can be estab- lished. Parts of this zone are now utilized for agriculture but when occasional abnor- mally high water occurs, the people with their pigs and chickens must retire to their houses on stilts and await the lowering of the flood waters. Such a system of agriculture re- stricts the number of crops which can be grown and perhaps invites disaster which might come in some excessively rainy period. Today, with powerful earth-moving machi- nery available, there is no doubt but what CARIBBEAN FORESTER engineers could lay out and erect a system of dikes and drainage which could convert extensive areas into highly productive farm land. An additional advantage of such diked lands over ordinary agricultural areas is that flood waters may be tapped at any planned time to deposit an enriching layer of alluvium over a given portion. Since such scientific agriculture in the Darién most probably await some future time when population expansion and world food needs are more pressing, first attention should be given to existing problems, but, at any rate, land use should keep in mind and not destroy the potentialities for such plan- ned future use. In this consideration the hilly areas and the wetter upsteam zones of Darién should be reserved in the near future to avoid agricultural use. This is desirable because a very low percentage offers promise for level agriculture and any widespread clearing would result in more rapid runoff and higher flood levels and thus destroy the potential value of the alluvial plains. The broken area up the Tuira River, and perhaps several other sections of the Darién Province might very well be set aside as na- tional parks. The beautiful stretches of the Tuira, with rocky ledges along the river and the attractive natural forest would someday offer great attractions for tourists, if the nat- ural conditions can be maintained. For this same reason, the development of a grazing industry in Darién is not consid- ered desirable. Although a very few exis- ting ranches have given good results and ob- viously, the climate and soils are satisfactory, any considerable extension of grazing would automatically lead to a greater and greater use of fire and the destruction of the hill forests. The potential value of the alluvial plains for mixed agriculture is so great that neither shifting cultivation in the uplands nor grazing on a large scale should be allowed to jeopardize their future use. Of all Panama, Darién Province does offer exceptionally favorable opportunities for in- dustrialization of forest products. The inter- nal system of waterways, the pure stands of JULY - DECEMBER 1956 10 se Fig. 5.- Deforestation of marginal land along the rivers in Darién is a common sight. Fig. 6.- The headwaters of the rivers in Darién have magnificent scenery. Some day they will constitute a true source of wealth to stimulate tourism and for hunting and fishing as well as for recreation aside from their protective value... if by that time they are still in their natural condition. 108 tide-land and the presence of very appreciable quantities of high quality woods in the dry land forests are here combined in a manner which is unique or rarely found in the Americas. The present exploitation of the forests in the area is a rather wasteful use of the forest resources and adds little to the development of the province. In the mangrove forest trees are felled for their bark alone with the whole trunk being left to rot on the soil. In the mixed hardwood forests, some of the logging operations take out only one or two species, such as mahogany and Spanish cedar, and ac- tually harvest only the straight logs or por- tion of the tree. No thought is given to the future of the forests. Here, is a clear case where the combination of forest resources presents the possibility of an integrated industrialization for real per- manent benefit to the province and the Re- public of Panama. Panamanian capital could well combine with foreign capital and tech- nical industrialization knowledge for mutual benefit. At the present time three types of industrialization processes appear to offer excellent opportunities. The first of these is a veneer or plywood plant, as Darién has large quantities of sever- al precious woods suitable for face veneers and also abundant supplies of less valuable woods for core stock. One plywood factory near Panama City has operated with timber supplies from Darién Province, although it is difficult to understand any advantages, if they exist, for the actual location of the plant in relation to supplies. Another type of industry would be feasi- ble here or would combine well with the ply- wood and sawmilling industry. This is that based on the Novapan process developed in Switzerland. In that process, lumber is ar- tificially built up from chipped wood on the same principal as that of plywood, in that an inferior wood is used for the major part of the board and faced on both surfaces with wood that is attractively grained or colored. Since all of the wood in this process is reduced to CARIBBEAN FORESTER chips or shavings, it is possible to obtain much of the raw material for the facing at least from what would normally be left in the woods as short lengths or large limbs or dis- carded as waste at a sawmill or plywood plant. The processed wood or chips are then mixed with glue and pressed into boards or products of similar form. This process has the advantage of permitting the addition of chemicals to prevent such deteriorating fac- tors as termite damage and because it can utilize so much material is to be recom- mended highly for industrial integration. A third type of board fabrication reduces the wood of one or several hardwooded species down to its fibers, much as in the pulp making process. These are then spread out into thick sheets subjected to heavy pressure and emerge as large sheets of a thick, strong fiber board. The fibracel plant oper- ating at Ciudad Valles, near Tampico, Me- xico is a sample of this type of plant. Such a plant might feasibly use such woods as man- grove or alcornoque which occur in pure stands over large areas close to the waterways. Any use of the red mangrove wood which could be combined with the extraction of the bark for tannin would be highly desirable. Once industrialization of the wood resour- ces of the Darién were under way, the devel- oped system of transportation would allow for harvesting and shipping specialty woods. Also, it is very likely that uses could be found for some of the abundant species such as cuipo which ere now considered worthless. The development of economic production vi pulp and cellulose from tropical woods, pro- duction of sugar from wood cellulose, and conversion of wood sugars to proteins in yeast cultures are some of the industrialization processes not far in the offing and these fac- tories will tend to move in where other in- dustrial plants have led the way. Other possibilities of more direct use sug- gest themselves also. Short lengths, large limbs and partly rotted logs of mahogany and other species could supply a plant making up JULY - DECEMBER 1956 furniture parts to be exported in unassembled form from the province. During the survey, we were impressed also by the tremendous numbers of the local palm called “guagara.”” This is a hard-fibered palm with a tall straight trunk probably averaging between 6 and 8 inches in diameter. It would appear worthwhile to carry on tests with this palm as a possible upright minetimber for export, because if suitable for such a use, the economics of extractions to shipping points seem satisfactcry. Summary In brief, Panama possesses an abundance of renewable natural resources, which if utilized correctly on a rational basis can develop enormous wealth and a general high level or living for even a greatly expanded population. However, to bring about this correct utiliza- tion will require careful planning and educa- tion of the general population in wise resour- ces use. Government leaders and local capi- talists must direct their efforts and money into those projects and areas which can be developed on a permanent basis with possibil- ities for profit not only for the land-owner and capitalist, but also which offer an cppor- tunity to raise the living levels of all who work on the projects. One of the most pressing needs of the country for such planned development, are local technicians in many land-use fields to carry on research, to serve as extension agents, or teachers, or to fill field posts as technicians or administrators. There is still time to do this while many of the natural resources are still more or less intact but procrastination in development of wise use of the resources while population numbers grow by leaps and bounds will make the task much more dif- ficult or even impossible after a few more years. Since the forest areas and resources are sv extensive and the economic possibilities for industrial forestry development offer such promise, one of the immediate tasks to be undertaken by the government of Panama 109 should be that of training forestry techni- cians and the establishment of an effective national forest service. Such a service should undertake at a very early date the reserva- tion of national forests and parks in exten- sive areas of the mountainous and hilly re- gions and also undertake studies in the for- ests which offer the best possibilities for in- dustrial development. The forestry indus- tries, which require heavy investments for their establishment are interested in long- term operations. Therefore, they are highly desirable, since they strive to maintain the forests on a permanently productive basis and work towards a better level of living of the inhabitants. Bibliography Braddy, T. W. 1922. Lumber development in Panama. Timberman 24(1):184. Cooper, G. P. 1928. The forests of Western Panama. Tropical Woods 16:1-35. Erlanson, G. O. 1946. The vegetation of San José Is- land, Republic of Panama. Smithsn. Inst. Misc. 106(12) 12 p. Garver, R. D. 1947. Informe de la Republica de Pa- Collect. nama. Revista de Agricultura, Co- mercio e Industria (Panama) 7(74) :9-28. Kluge, H. C. 1926. Trees of the Bayano River Watershed, Panama. ‘Tropical Woods 5:4-13. Lamb, Bruce F. 1953. The forests of Darién. Caribbean Forester 14:128-135. Lindsay, Walter R. 1945. Plant resources of the Panama. In: Frans Verdoorn — Plant and Plant Science in Latin America. Walthan, Mass. Chronica Bota- nica. p. 67-68. 110 Pope, Fred W. 1952. A study of weather conditions in Panama, with special emphasis on the belt of doldrums. Canal Zone, 5700th Reproduction Unit Al- brook A.F.B. 21 p. Rubio ,Angel 1949. Vegetacién y paises panamefios. Sueldos, Ingenieria y Arquitectura 26:328-344. Schory, Robert W. 1943. A few facts concerning the flora of Panama. In: Frans Verdoorn. Plant and Plant Science in Latin America. Walthan Mass. Chro- nica Botanica, p. 285-287. Standley, Paul C. 1928. Flora of the Panama Canal Zone. CARIBBEAN FORESTER Contr. U.S. Nat Herb. ton) 27:1-416. Standley, Paul C. 1937-38. Flora of Costa Rica. Museum Bot. Serv. 18:1-1616. Smith, R. T., and other. 1945. Soil survey of the Darién Provin- ce, Republic of Panama. United Fruit Co., Division of Tropical Research, La Lima, Honduras and Chiriqui Land Co., Puerto Axrmuelles, Panama. 10 p. (type- written). Striker, Marion M. 1952. Soil and land investigation in Panama. Wash. D.C. Office of Foreign Agricultural Relations, U.S.D.A. (Washing- Field 7 o puts, ny cate te y* =) Sf ¢ ot aa -s ~ cP oe by mn * a aR" J “ a =. - a ie a ~~ =a Ey