Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. CARIBBEAN FORESTER U. S. DEPT. OF AGRICULTURE TAS AMI Ee A TIPRARY i A ASS NOV 1 6 1962 CURRENT SEXIAL RECORDS INSTITUTE OF TROPICAL FORESTRY e FOREST SERVICE U. S. DEPARTMENT OF AGRICULTURE © RIO PIEDRAS, PUERTO RICO VOLUME 23 © NUMBER 1 ® 1962 Caribbean Forester El Caribbean Forester es una revista semes- tral gratuita publicada en Puerto Rico desde el ano 1938 por el Instituto de Dasonomia Tropical del Servicio Forestal del Departa- mento de Agricultura de los Estados Unidos. Esta publicacién esta dedicada a promover la mejor ordenacién y utilizacién de los re- cursos forestales del trdpico con especial én- fasis a la regién del Caribe. Provee informacién a los que laboran en la dasonomia y ciencias afines sobre los pro- blemas especificos que confrontan, las politi- cas forestales vigentes y el progreso del tra- bajo que se lleva a cabo para mejorar la or- denacion y utilizacién de los recursos fores- tales tropicales. También sirve como medio informativo sobre los resultados y el progreso de los programas experimentales, en ordena- cién forestal tropical y utilizacién, que se Ile- van a cabo en el Instituto de Dasonomia Tropical en Puerto Rico. También le brinda una oportunidad a otras personas interesadas en la dasonomia tropical para presentar el resultado de sus trabajos. Se solicitan aportaciones de otras fuentes en el campo de la dasonomia tropical siempre que no estén considerdndose para publicacién en otras revistas. E] manuscrito generalmente no debe exceder 20 paginas escritas a maqui- na a doble espacio, aunque ocasSionalmente po- dria aceptarse un articulo mds largo cuando tuviera un interés especial. Los articulos deben someterse en la lengua verndcula del autor, deben incluir su titulo o posicién que ocupa y un resumen corto. De- ben estar escritos a maquina a doble espacio, solamente en un lado de la pagina, en papel blanco primera, tamafio 814 por 11 pulgadas. Las tablas deben numerarse consecutiva- mente, cada una en una hoja separada con su titulo. Las notas al pie usadas en las ta- blas deben escribirse a maquina como parte de la tabla y designarse por medio de nt- meros. Las ilustraciones deben designarse con nt- meros y numerarse consecutivamente. Los ti- tulos para cada ilustracién deberdn someterse en una pagina separada. Las fotografias so- metidas como ilustraciones deben ser claras, bien definidas y en papel glaseado, preferible- mente 5 por 7 u 8 por 10 pulgadas en tamafio. Las notas al pie deben numerarse consecu- tivamente con un nimero de llamada siguiendo la palabra en el texto a la cual hace referen- cia la nota al pie. La nota al pie debe apa- recer en el texto en la linea siguiendo el ni- mero de referencia y separada del texto por medio de una linea corta hacia dentro desde el margen izquierdo del texto. Las notas al pie se usan para dar crédito a material no publicado y a comunicaciones. Si se hacen solamente unas pocas referencias a la litera- tura entonces dichas citas pueden aparecer como notas al pie. Las citas incluirdn el nom- bre del autor, el afio de publicacién, el titulo del trabajo, y el nombre y paginas de la pu- blicacién. Los manuscritos deben enviarse al Director del Instituto de Dasonomia Tropical, Rio Piedras, Puerto Rico. Las opiniones expresadas en esta revista no coinciden necesariamente con las del Servicio Forestal. Los articulos publicados en el Carib- bean Forester pueden reproducirse siempre que se haga referencia a la fuente original. The Caribbean Forester is a free semi-an- nual technical journal published since 1938 in Puerto Rico by the Institute of Tropical Forestry, Forest Service, U. S. Department of Agriculture. This publication is devoted to the development of improved management and utilization of tropical forest resources, with special interest in the Caribbean region. Through the pages of the journal tropical foresters and workers in allied scientific fields are informed of specific problems of tropical forestry, policies in effect in various countries, and progress of work being carried out for the improvement of the management and util- ization of forest resources. It furnishes a means of distribution of information on the progress and results of the experimental pro- grams of the Institute of Tropical Forestry -in Puerto Rico. In addition, it affords an op- portunity for other workers in the field of tropical forestry to make available the results of their work. Contributions for the journal are solicited. However, material submitted should not be under. consideration for publication elsewhere. Manuscripts should not ordinarily exceed 20 (Continia en la portada #3) The printing of this publication has been approved by Director of the Bureau of the Budget (June 26, 1958) The Institute of Tropical Forestry is operated in cooperation with the University of Puerto Rico, VoL. 23 No. 1 - 1962 CARIBBEAN FORESTER Caribbean Forester Gomi mts SHUR eAeliGike Page Annual Report for 1961 - Institute of Tropical Forestry —__ 1 Medicion del Crecimiento de los Arboles en los Bosques pOpicales eee = ees 7 15 C. B. Briscoe The Status and Development of the Nicaraguan Pine Savannas ____ Zi B. W. Taylor Report on 1961 Tropical Forestry Short Course _________ Zt H. Barres Modificacion del Programa de Ensenanza __ 33 Gerardo Budowski Forests and Dominant Legumes of the Amatuk Region, British Guiana ______ = ae wes 30 B. A. Whitton > re VOL. 23 No. 1 - 1962 Annual Report for 1961 Institute of Tropical Forestry Looking back over 1961, the event of greatest potential significance to tropical forestry was diplomatic in character, rather than technical: the signing of the Alliance for Progress by the Organization of American States at Punta del Este, Uruguay. The Al- liance is, among other things, an expression of common concern regarding the under- development and misuse of natural resources in Latin America. It was a general resolution to place the solution of these problems high on the priority list, and the United States agreed to provide liberal assistance. Implicit in the objectives of the Alliance is better man- agement of forest lands, through (1) their identificaction and classification as such in programs of agrarian reform; (2) procection from fire, irrational exploitation, and cultiva- tion; (3) improved tenure; and (4) positive efforts to raise and sustain their productivity to a maximum. Other events during the year further man- ifest growing international recognition of the need for better management of forest re- sources. Mexico, with the assistance of FAO, is undertaking a national inventory of forest resources. Forestry education within the region is being expanded, The Latin Ameri- can Institute for Forestry Training and Re- search at Mérida, Venezuela, was strengthen- ed in 1961 by financial support from seven Latin American countries. The graduate training program in forestry offered at the Inter-American Institute of Agricultural Sciences in Turrialba, Costa Rica, was ex- panded by a grant from the FAO Special Fund. Both FAO and the United States are assisting in the development of a new profes- sional forestry school at Vicosa, Brazil. Basic forest research was undertaken as a result of Public Law 480 grants by the United States to outstanding scientists in Colombia, Pert, Brazil, and Chile. The government of Chile, with assistance from the FAO Special Fund, has agreed to set up a large national forest research institute. The Tropical Forest Research Center, as the sole permanent field office of the U. S. Forest Service in the Latin American region, has watched these developments with much interest. They portend growth in the impor- tance of forestry in Puerto Rico, where re- search and other efforts to solve forestry pro- blems common to much of the region have been in progress, Many of the foresters now called upon for these expanded programs ob- tained part of their training in Puerto Rico. The Alliance for Progress and the new educa- tional and research programs being under- taken signify a growing demand for foresters and technical forestry information. General acceptance of the growing role of the Forest Service in Latin American forestry was the motive for conversion of the Tropical Forest Research Center to the Institute of Tropical Forestry this year, placing greater stress upon the international aspects of the work, Research in forest management and utilization, public forest administration, and assistance to private forest landowners have also progressed. The Institute of Tropical Forestry was represented in the United States delegation to the Second Session of the Regional Com- mittee on Forest Research of the Latin Amer- ican Forestry Commission of FAO, held in Caracas, Venezuela, March 1961. The Di- rector of the Institute, as chairman of the Section on Planting of the Committee, report- ed on two years’ work in collecting data on 9 plantations throughout Latin America, pub- lished by the Institute as a supplement to Volume 21 of the Caribbean Forester. The Director was asked to continue to head the Section on Planting until a successor could be found. In this capacity he took measure- ments in more than 100 additional outstand- ing forest plantations in Trinidad, Chile, Ar- gentina, and Brazil. Most of these data have since been published in the Caribbean Forest- er. In August the responsibility of the Insti- tute was shifted to direction of the Section on Forest Research Evaluation of the Re- search Committee. The Institute was represented also at the Second World Eucalyptus Conference, held in Sao Paulo in August, where the Director served as head of the U. S. Delegation. There, as regional reporter for Latin America, he presented a paper summarizing progress with eucalyptus in this area since the previous conference. He also submitted to the Con- ference: (1) summaries of data collected in more than 100 outstanding eucalyptus plan- tations throughout Latin America, and (2) “Statistically Valid Planting Trials,” a tech- nical paper prepared by a staff member and directed toward more effective regeneration research in Latin America. The introduction of a seccion on Forestry in the Pacific Science Congress, held in Hawaii, August 21 to September 6, led to an invitation to the Institute to present a tech- nical paper on a subjecé of pantropical scope. The forest management research project lead- er participated and presented a paper on tree measurement in the tropics. The s.atf of the Institute has had the ben- efit of a greater number of personal contacts with tropical forestry and foresters here than in the past. In addition to the students who attended the tropical forestry short course, the Institute was host to 18 professional foresters of long experience from 11 foreign countries. The staff studied forestry first- hand in Trinidad, Chile, Argentina, and Bra- CARIBBEAN FORESTER zil. These contacts have led to continuing technical correspondence of mutual benefit. Forestry research for Puerto Rico and the Virgin Islands continued to be concentrated on the selection of trees for the forests of the future. Adaptability tests with recently se- lected species were expanded on new sites in the coffee and limestone regions. Past growth data from more than 25,000 trees, too voluminous for complete analysis by former techniques, are being reanalyzed elec- tronically. The search for superior pheno- types is continuing and comparative tests of the properties of wood from selected trees suitable for intensive management are being planned. Early indications all point to the prospect of far superior trees for future for- estry as a result of such research. The scope of the program of the Institute within Puerto Rico and the Virgin Islands has not changed during the past year. It includes, in addition to research in forest management and forest utilization, multiple- use administration of the 27,000-acre Luquillo Experimental Forest, cooperative assistance to forestry on nonfederal lands within both Puerto Rico and the Virgin Islands, and training in tropical forestry. The accomplishments of the Institute are in part the product of generous cooperation by a number of local agencies, industries, and individuals. Headquartered on _ the grounds of the University of Puerto Rico, the Institute has enjoyed scientific collaboration by the Agricultural Experiment Station of the University in the form of technical coun- sel by scientists on fields allied to forestry and in data processing. The Agricultural Extension Service, also of the University, has provided material assistance in the processing of photographs and numerous mimeographed publications, and in arranging field demon- strations. The Division of Forests of the Puerto Rico Department of Agriculture has worked directly with the staff on field experi- ments and demonstrations, and has provided VOb 235NOe L962 land, materials, and equipment as needed. The Virgin Islands Corporation has financed, through both grant and revolving funds, for- est research work in St. Croix which other- wise could not have been undertaken. The Virgin Islands Agricultural Program provided office, nursery space, use of equipment, and technical counsel for the program there. Local manufacturers of furniture and other wood products have provided materials for forest utilization research. Sites for the test- ing of reforestation techniques in Puerto Rico and St. Croix were provided by more than 50 landowners, FOREST MANAGEMENT RESEARCH Tests of species adaptability continue to dominate the forest management research program. In the field as a whole 135 studies were active at the beginning of the year. Nine new studies were begun during the year and 75 were closed or combined, leaving the number of studies active at the end of the year at 69. DENDROLOGY A torest arboretum, including tenth-acre plots of each of the major species incorporated in adaptability studies, was begun late in 1960. Species added this year bring the total] to forty. For a few species lack of planting stock has forced use of plots smaller than tenth-acre. Final edicorial revision of the manuscript “Arboles Comunes de Puerto Rico e Islas Vi: genes” was completed, making probable its publication by the University of Puerto Rico during 1962. PHENOLOGY Coordinated weekly measurements of rain- fall, temperature, humidity, and circumferen- tial growth were continued at four locations in the Luquillo Forest. Analysis of two years of data has begun. VARIATION AND SELECTION Additional outstanding individual trees of mahoe (Hibiscus elatus Sw.), teak (Tec- tona grandis L.), bigleaf mahogany (Swiete- nia macrophylla King), small-leaf mahogany (S. mahagoni Jacq.), and Honduras pine (Pinus caribaea Morelet v hondurensis) were located and marked for later use in progeny and clonal testing. Attemp‘s without auxins to root cuttings from mature trees of bigleaf and small-leaf mahoganies were unsuccessful; new leaves were produced at all three seasons of collec- tion, but no roots were initiated. SITE IMPROVEMENT First-year results of fertilizing established teak plantations indicated that fertilization at all levels tested increased diameter growth. Detailed analyses will not be attempted until data for a longer period are at hand. Early results from a second tes¢ of ferti- lizers showed that (1) fertilized hardwood seedlings grew significantly more rapidly than unfertilized seedlings on a well-drained clay loam; (2) fertilization caused no increase in growth on a heavy clay subsoil with a shallow hardpan; and (3) pine growth was not affect- ed by fertilization on either site. NURSERY PRACTICE Large cuttings, for live fence posts, of Gliricidia sepium (Jacq.) Sleud and Erythri- na berteroana Urban rooted well in March, July, and November, whereas cuttings of Ficus laevigata Vahl collected at the same times, rooted very poorly, in spite of the rep- utation of this species as a live post. Small-scale tests indicated that fertilized teak sawdust is a satisfactory potting medium for pine, and that seedlings in polyethelene bags only 4 x 6 inches (flat dimensions) develop satisfactorily for planting stock. Both studies will be repeated on a more conclusive scale during the coming year. CARIBBEAN FORESTER Figure 1. ANTHOCEPHALUS CADAMBA at 18 months. Left - Friable clay loam, 10 ft. Right - Poor site, 0.6 ft. Vol. 23 NO: tea 1962 SPECIES ADAPTABILITY Adaptability studies are now in progress at 35 test locations and with 48 species, 20 of which are pines. Twenty-two of these locations are on the lands of private coopera- tors, some of whom provide complete planta- tion care. The development of some of the trees under test is summarized in Tables 1 and 2, presenting heights measured 24 to 27 and 12 to 15 months, respectively, after out- D planting. The clay soil used two years ago is clearly seen to be inferior to the clay loams planted one year ago. Site quality is seen to be very important, especially for the hard- woods. Cadam (Anthocephalus cadamba), for example, on the best plot averaged 2500 percent taller than on the worst plots. Although this is the extreme, differences of more than 300 percent are common. Dziffer- ences in survival percentages, not given, are almost as striking. Table 1. Tree heights'/ after two growing seasons. | Sandy Loam Soil ; a Clay Pe we Species | Plot Means Tallest Plot Means? —=—‘Tealllest ees Max. Ay. Tree Max. Ay. Tree Feet Spathodea campanulata 16.3 5.2 22 — — — Cecropia peltata 13.2 7.0 Zn — — — Eucalyptus patentinervis alg 6.9 21 — — = Pinus caribaea v. hondurensis 7.9 D1 ibys 1.8 126 4 Anthocephalus cadamba — — = et 4.8 9 Pinus caribaea v. caribaea 4.3 2.8 8 — _ Hibiscus elatus — — a 4.0 ose 8 Schizolobium parahybum, Brazil = — — Sal 2.0 5 Swietenia mahagoni — — — 2.9 1.4 4 Khaya nyasica ~~ = — Paral 1.8 3 Enterolobium cyclocarpum -— — — 2.0 let 3 Platanus occidentalis 2.0 i 2 — — — Schizolobium parahybum. Guatemala — — — 1.5 1.4 2 Swietenia macrophylla — — -~ 1.4 V2 3 Tectona grandis — — — 0.5 0.2 2 1/ To completed feet, therefore trees with a mean measured mately 2.5 feet. 2/ Poor, eroded site with shallow hardpan. height of 2.0 feet have an actual average height of approxi- 3/ Each plot value was assigned unit weight t% computing mean for soil type. 6 CARIBBEAN FORESTER Table 2. Tree heights'/ after one growing season. ____—Sandy Loam Soil” = Clay Soil Species Plot Means? Tallest Plot Means? Taliest oe _ _ | Max. Av. Tree Max. Avs Tree Feet Anthocephalus cadamba — — — 12.4 4,2 16 Casuarina equisetifolia 11.9 6.4 20 8.2 6.4 15 Hibiscus elatus 10.9 4.5 15 9.5 4.9 13 Enterolobium cyclocarpum 9.8 7.3 16 6.5 5.2 11 Schizolobium parahybum, Brazil — — — 8.8 5.6 11 Eucalyptus patentinervis — — — 8.5 4.6 14 Pterocarpus indicus — wee — 6.1 4.8 11 Schizolobium parahybum, Guatemala — os a 5.1 2.8 9 Cupressus lusitanica 4.5 4.5 6 AJ 2et 7 Swietenia mahagoni, Puerto Rico — — — 4.5 2.6 4 Khaya nyasica 1,5 1.0 4 4.4 2.0 7 Pinus caribaea v. hondurensis 3.9 2.8 8 4.1 2.4 6 Swietenia mahagoni, Jamaica — — — 4.0 3.3 6 Swietenia macrophylla — a — 3.3 1.8 6 Tectona grandis 2.9 1.0 12 320 i a 6 Cybistax donnell-smithi 2.9 Lo 3 1.9 1.4 3 Pinus caribaea v. caribaea — =. — 2.9 2.4 6 Samanea saman 1.0 0.4 1 200 1.4 4 Carapa gulanensis — — 4.0 2.4 6 Cedrela mexicana?/ — _ — 1.6 0.8 3 Swietenia humilis = --- = 15 i 4 4 Pinus elliottii v. densa — — —_ 1.5 12 3 Pinus occidentalis 1.5 0.9 a — a — Hernandia sonora — = os 1.4 1.0 3 Pinus massoniana 1.4 0.9 4 1/ To completed feet, therefore trees with a mean measured height of 2.0 feet have an actual average height of approxi- mately 2.5 feet. 2/ Each p'ct value was assigned unit weight in computing mean for soil type. 3/ Direct seeded. New species or seed sources outplanted at two or more locations during the year were: Cordia alliodora Costa Rica Eucalyptus Bangalore hybrid Khaya senegalensis Sudan Maesopsis emini Uganda Pinus douglasiana Mexico P. echinata United States P. elliottii elliottii United State» P. michoacana Mexico P. montezumae Mexico P. oocarpa Guatemala P. oocarpa Mexico VoL. 23 No. 1 - 1962 P. pseudostrobus P. strobus chiapensis P. taeda Pseudocedrela kotschit Taxodium mucronatum GROWTH OF TREES AND STANDS Collection of descriptions of promising for- est plantations in Latin America, begun in 1959, was extended to southern South Amer- ica; 110 new plantations were studied in five couniries. Reports have been prepared, in both English and Spanish, and added to the previous compilation appearing as “Records of Forest Plantation Growth in Mexico, the West Indies, and Central and South Amer- ica,’ Caribbean Forester 21, Supplement. A study of the effect of different cutting cycles upon the yield of fence posts from mangrove naturally regenerated after clear- cutting was initiated during the year. Prelim- inary results indicate that in unthinned stands the production of fence-post sized trees is negligible at age 6. At 8 years the mean annual increment was 72 posts per acre, and at 10 years 276 posts per acre. Yields ~l Mexico Mexico United Siates Sudan Guatemala at greater age and from stands subjected to thinning are not yet known. CHEMICAL ARBORICIDES The success in Uganda of tree poisoning without the use of frills led to a study of this technique in the Luquillo Forest, where a large area is being subjected to stand improve- meni. The study included 80 trees of 238 species, ranging from 4 to 12 inches, d.b.h. Chemicals used were Weedone and 2,4-Dow 40, mixed on an acid-equivalent basis in diesel oil. They were applied from 1-gallon cans with nail-hole orifices in the spouts. The bark of trees not frilled was wet in a contin- uous band 6 inches wide around the tree at about two feet above the ground. Rainfall about 5 hours before treatment left the bark moist but not wet when treated. Six hours after treatment more rain fell. The results to date are shown in Table 3. Table 3. Three-month and six-month effects of tree poisoning. TREATMENT = ordi Dead : Vigor - Normal 2,4,5-T 2,4-D Frills 3 mo 6 mo. 3. mo 6 mo. 3 mo. 6 mo. % % % Te % % Te % Current 0.89 Yes 33 67 47 13 20 20 Similar, with D 0.74 1253 Yes 13 2 60 46 Ar PAE | Similar, no frill 0.62 1.30 No fi 50 73 SY 20 13 High T 3.00 No 33 80 60 20 rl 0 High T & D 2.00 4.00 No 67 87 26 6 7 7 It is apparent in Table 3 that by increas- ing the concentration of 2,4,5-T it was possible to obtain as complete a kill without frills as is to be expected from the technique current- ly in use. No clear advantage was seen in adding 2,4-D. The added cost of the high-T solution as compared with that currently in use is more than offset by savings in frilling costs. The resulis further suggest that lower concentrations of 2,4,5-T may also prove 8 satisfactory. Additional tests will relate ef- fects to season and to wetness of the bark at the time of application. PILOT MANAGEMENT More than 6,000 acres of secondary stands in the Luquillo Experimental Forest have been subjected to systematic management to increase productivity. During 1961, the sixth year of such management, the first improve- ment cutting was completed in all but a small area to be acquired by a land exchange. In addition, during the cycle 91 acres were re- forested and 838 acres of plantations were released. Oe... Post of Casuarina 18 years after treatment with Carbolineum, set in CARIBBEAN FORESTER Preparatory to the next treatment of this forest a field inventory was completed during 1961 which, when fully analyzed, will be used io determine the type and priority of further silvicultural work in the various compart- ments. Field data were also collected to determine the abundance and quality of na- tural regeneration resulting from the first treatment, Results, not yet complete, indicate that natural regeneration is generally ade- quate in quantity, but the better species are not always well represented. Other recent cata on artificial regeneration and the poten- tial utility of a number of native woods will! be used in drawing up the second management plan for this area during the coming year. forest with high humidity and more than 100 inches annual rainfall. Vou. 23 NO: 1 = 1962 The first silvicultural treatment of the pilot management area greatly benefitted the spacing of the trees and the composition of the forest. Nevertheless, the absence of high quality trees in the stands and the need to eliminate many of no value required an inves:ment much greater than the value of the timber yield. An objective of this proj- ect in the future will be to expand utilization to a point that silvicultural work can be supported by receipts. To this end, a small utilization plant in the forest is planned, to be operated by an individual cooperator or a group organized as a cooperative. Process- ing will include preservative treatment of roundwood, sawmilling and seasoning of lum- ber, and later possibly also secondary manu- facture, such as novelties and cabinet work. FOREST UTILIZATION RESEARCH The chiei line of utilization research in recent years has been preservative treatment of fence posts. In 1961, with tests of the more promising nonpressure techniques of preservation completed, emphasis shifted to the study of service life of treated posts and the seasoning of lumber. A vacancy in the project leader position during part of the year resulted in slower progress than had been anticipated. WOOD PRESERVATION Posts of Casuarina (Casuarina equiseti- folia L.) are commonly produced in farm plantations. Their service life is seldom more than 2 years. The earliest test of preserva- tive treatment by the Institute was made 18 years ago with this species. The preservative used was carbolineum, applied by the hot- and-cold bath technique. The treated posts of this test, set beneath a forest subject to continuous high humidity and more than 100 inches of rainfall annually are still sound. Other commonly used posts are eucalyptus (Eucalyptus robusta J. E. Smith), a planted exotic species; and mesa(Micropholis chrvyso- 9 phylloides Pierre), a common tree native to forests above 2,500 feet elevation. Posts of these two species, treated with carbolineum by hot-and-cold bath, are all still sound after 12 years of service on the northern coastal plain and at 2,500 feet elevation in the mountains. More recently the promising results ob- tained elsewhere with simpler techniques and more convenient preservatives led to a test of the cold-soaking method, using 10 percent pencachlorophenol and posts of 57 species, After ten years of exposure, 56% remain serviceable at sea-level and 95% at 2,500 feet elevation. A more definitive comparison of treating methods was undertaken in 1958. Posts of 52 species were treated by the cold-soaking method and 21 species by the hot-and-cold bath method, both using 5 percent pentachlo- rophenol in diesel oil. In addition, ten species were treated with a 50-50 creosote and diesel oil solution by both methods. Thirty species were treated by the double diffusion method with two sets of solutions: (1) sodium fluoride and copper sulfate and (2) copper sulfate and sodium chromate-sodium arsenate. Untreated posts were set as controls. After three years of exposure, both at sea level and in the mountains, 100 percent of the untreat- ed posts have failed due to decay or termites, but no failures of treated posts have yet taken place. SEASONING Local lumber dealers and furniture man- ufacturers have long recognized problems re- lated to the moisture content of wood. Lum- ber imported from different sources, or even repeated shipments from the same source, has varied widely in its moisture content at the time of arrival. Prompt use of such lum- ber has led to problems of checking, warping, and shrinkage during and after manufacture. To date these problems have precluded large- scale shipment of manufactured items to the 10 continental market. The first steps toward the solution of this problem, the use of mois- ture meters and air-drying for a period prior to manufacture, have been taken by some of the more progressive furniture factories. However, accelerated drying of lumber to a controlled moisture content near that which will prevail during use of the product, is not yet a common practice. On the as- sumption that kilns must be installed locally for this purpose, the Institute purchased a 500 board-foot experimental and has begun testing schedules for the more common- “5 ly used tropical hardwoods. kiln Attention was drawn in 1961 to the effec- tiveness of tests at the Forest Products Labo- ratory at Madison with what was called a E = ¥ igure 3. Solar Mrier. maximum insolation. CARIBBEAN FORESTER “solar predrier.’”’ There lumber has been dried rapidly merely by placing it in an insulated, transparent structure subject only to solar heat, with internal circulation fans and vented to permit escape of vapor. Several factors of the Puerto Rican environment suggested that such a technique might prove practical. he use of a large number of distinct lots of lumber from various sources makes desirable a technique simple and adapted for small- scale operations. Conventional kilns are ex- pensive to operate as well as to install. The local climate is warm the year around and with some direct sunlight almost every day A test drier with a capacity of 2,000 board feet was constructed. The structure is about 14 feet long (east to west) and 10 feet wide. ene cheatin Note open vents at bottem, and black | plates underneath ‘roof for Vou. 25 No: = 1962 The south wall is about 10 feet high and the north wall is 13 feet, making the pitch of the roof approximately perpendicular to 'the mean position of the sun at noon in this latitude. The north wall is sheathed with plywood, and the roof and all other walls are sheathed, both outside and inside, with ‘transparent plastic film, providing a 1% -inch dead-air space. Noon air temperatures within the drier range up to 40°F higher than outside, early morning temperatures about 10°F. The first test of the solar drier in Puerto Rico was made with 5/4 mahogany (Swiete- nia macrophylla King) with an initial mois- ture content of 50 percent. The lumber reached equilibrium moisture content (14 percent) in 19 days, although 14.92 inches of rain fell during the period. After 29 days, the moisture content had dropped to 8.5 percent, while a comparable roofed pile out- side retained 29 percent. Subsequent tests have shown even more rapid drying possible during better weather. Drying defects, most- ly end-checking, were more pronounced in the pile outside than in that inside the drier. Experience to date indicates that solar drying can be so effective that no kiln drying need follow its use. Much interest has been shown in this process by the local wood in- dustry. For further tests the structure is to be enlarged to accommodate longer material. FOREST ADMINISTRATION The Luquillo Experimental Forest, while devoted primarily to research, continues as an increasingly important example of multiple- use public forest land management in the tropics. Its geographic location between the United States and much of Latin America enhances its value to visitors from both areas as a demonstration of the results of good forestry. Both the demand for more inten- sive use of this area and the number of visitors are increasing rapidly, Studies of virgin forest ecology, silviculture of naturally established forests, reforestation, li plantation management, and watershed man- agement are either under way or planned for tracts distributed throughout this forest and covering more than half its total area of about 27,500 acres. During the past year a study of natural regeneration was intensified on 300 acres. A study of stand characteristics was begun on more than 6,000 acres as a preliminary to intensification of pilot man- agement on this entire area. Timber management is also being inten- sified. The established plantations, mapped in 1960, are being subjected to drastic release of selected crop trees for rapid future incre- ment. A total of 197 acres of plantations were treated during the year. Because of simpli- fication of the procedure, and particularly the application of poison without frilling, average stand improvement costs for planta- tions and natural forests declined $3.41 to $8.62 per acre. Further economies are in sight. Nearly 40,000 trees were planted to reforest openings. About 26,000 board feet of timber was sold. This, plus other forest products yielded $1,636, of which more than one-third was reinvested in betterment of stand conditions on the areas from which the material was sold. Use of the Forest for recreation, including the smaller more isolated Toro Negro Divi- sion, increased 10% over that of 1960. More than 288,000 recreation visits to the area were made during the year. This type of forest use is concentrated at the La Mina Recreational Area and two. organization camps. The rapidly increasing use of the Forest for recreational purposes has led to plans for expansion of facilities, particularly picnic areas, for the enjoyment of the public. The demonstration of integrated accom- modation of all uses in the public interest is a guiding policy in the administration of this forest. A number of continuous uses of the Forest by individuals, companies, or agencies are authorized under special use permits. During 1961 there were currently 185 such permits in effect (in both the Luquillo and Toro Negro forests). ‘They yielded about $9,800 in fees. These are for farming, elec- tronic installations on the peaks, residences, rights of way, camps, and other purposes. A growing number of applications for such permits is being received. FORESTRY COOPERATION The Institute cooperaces with local govern- ments, industries, and individuals in a broad range of forestry activities, both in Puerto Rico and the Virgin Islands. Outstanding among cooperative activities in Puerto Rico is the sharing of costs with the Division of Forests of the Puerto Rico Department of Agriculture for the production and distribution of planting stock for farm forest plantings in accordance with tho Clarke- McNary Act and the related Cooperative Forest Management program of farm forestry assistance. Both are administered by the Figure 4. Visitors at La Mina Recreational Area on a typical Sunday. CARIBBEAN FORESTER Sait ROE ROPERS Division. During 1961, the Division received 1,696 requests for assistance from landowners in the area of concentrated activity, about one- third of Puerto Rico. Technical assistance was offered and 1,023,000 trees were provided for the planting of 481 acres of farm forests. Compared to 1960, this is an increase of 21 percent in number of trees and of 128 per- cent in number of acres planted. Staff liaison with the Division of Forests in ‘the administration of public forest lands continued. Specific activities included joint consideration of mutual recreational area de: velopment responsibilities, reforestation, for- estry publicity, and the training of personnel Cooperation was offered also to processors of forest products in Puerto Rico. Furniture and millwork manufacturers were shown the effectiveness of the solar drier. Small lots of imported lumber were kiln-dried to demon- strate to industry the effectiveness of this VoL. 23 No. 1 - 1962 process, little used here. Local woods were provided to a number of manufacturers for testing. The technique of treating fence posts was the subject of 10 rural demonstra- tions organized through the Agricultural Ex- tension Service. In the Virgin Islands the forestry program sponsored by the Virgin Islands Corporation continued as an Institute project. This pro- gram so far concentrated on the island of St. Croix, involves a broad range of activities, each on a small scale. Mahogany seed of the recently recognized intermediate strain was collected for a number of requests from foreign areas. A total of 12,800 mahogany trees were produced in the nursery. Of these, 7,370 were used in forest plantings, bringing the total to more than 86,000 mahoganies (and 37,500 teak) planted since the program started in 1954. Additional trees were mado available to the public for other plantings, 400 were set by the program along roadsides, and 900 were shipped to the British Virgin Islands. Forest planting in the Virgin Islands was confined to 13 acres in St. Croix, all done in strips cleared through the brush. Replanting was done in plantations with a gross area of 120 acres. Of this area, 53 acres are publicly owned, Weeding and release were done on 168 acres. The cost of all labor used on private lands was reimbursed by snulg [SE] papquipd 4a DaDquind snuig 4 75 VIVWALWNO , ® . § of OOIX4IW id VoL. 23 No. 2 - 1962 As a result of the investigations this species is divided into three varieties: Pinus caribaea var. caribaea (typical) from Cuba, P. caribaea var. hondurensis frorn Central America, and P. caribaea var bahamensis from the Bahamas. The most important characteristics of these entities are the following: PINUS CARIBAEA Morelet var. CARIBAEA (typical) Needles in fascicles of 3 (rarely 4); cones 5-10 cm. long; seeds with adnate wings (remaining attached). It is found on isla de Pinos and Pinar del Rio, western Cuba, at elevations from 150 to 1150 feet, in tropical climate (annual average temperature 76 - 78°F) subhumid and humid (annual rainfall 47 - 63 inches), with six months drought; acid soils (pH 4,5 - 6). PiNUS CARIBAEA Morelet var. HONDURENSIS nov. var. Needles in fascicles of 3, sometimes 4, 5 (and 6 in young trees), cones 6-14 em. long; seeds with articulate wings (wings become detached), except a low percentage with adnate wings. Occurs on the Atlantic slopes in Central America oi British Honduras, Guatemala, Honduras, and Nicaragua, from sea level to 2,800 feet, in tropical or subtropical climate (70 - 81°F), from subhumid to super- humid (annual rainfall 38 - 140 inches) with a two - six months drought 6] pericd; acid soils (pH 4 - 6,5). PINUS CARIBAEA Morelet var. BAHAMENSIS nov. var. Needles in fascicles of 2 and 3; cones 4-12 cm. long; seeds with articulate wing, rarely adnate. It is found on Bahamas Islands: Grand Bahama, Great Abaco, Andros, New Providence, and Caicos from sea level to 100 feet in tropical climate, (77°F), subhumid (annual rainfall 30 - 50 inches) with six - seven months drought; alkaline soils (pH 7,5 — 8,5). En las tltimas décadas, se ha despertado un enorme interés por el cultivo de un grupo de pinos, que hasta hace poco se reunian bajo el nombre de Pinus caribaea Morelet y que viven naturalmente en el sudeste de los Estados Unidos, Bahamas, Cuba y desde Honduras Britanica hasta Nicaragua, por lo general en sitios de poca elevacién. Estos pinos aparecen en forma intensiva en los programas de forestacién de numerosos paises del hemisferio sur, dado su rapido crecimiento y miultiples usos. La especie mencionada fué dividida por Little y Dorman (1952) en Pinus ellioitii Engelm. nombre dado al “slash pine” del sudeste de los E, U. A., y Pinus caribaea Morelet para los pinos de Cuba, Centroamé- rica y Bahamas. A pesar de este criterio, muchos forestales consideran al pino conti- nental centroamericano como una entidad di- ferente del “pino del caribe” de Cuba. En efecto, al cultivar estos pinos en Argentina, se notaron diferencias tanto en su _ habito, crecimiento, precocidad, tamafio y forma de las semillas, como en sus exigencias ecoldgicas. Con tal motivo se resolvié realizar un estudio taxondémico de los pinos del litoral atlantico centroamericano, que posteriormente se ex- tendié a las Bahamas con el objeto de abar- car toda el area geografica de la especie. Se encontraron algunas diferencias morfolégicas entre las poblaciones antedichas comparadas con la forma tipica de Cuba, tales como ala de la semilla articulada y hojas de a 2 y 3 por fasciculo en las Bahamas, y en Centro- américa ala de la semilla generalmente arti- culada, conos con gran variaci6n en el ta- mafio aleanzando hasta 41 cm. de largo. Se observaron ademas caracteres diferenciales en los conos, habito, formacidn de hojas aci- culares secundarias en plantas jdvenes, y otros que se detallan en este trabajo. El ala de la semilla en el género Pinus, cuando presente, puede ser: articulada cuando se separa facilmente de la semilla sin que- brarse ni dejar restos en la misma, 0 adnata 62 cuando no puede ser separada sin ser lasti- mada o dejar restos en la semilla. Este ca- racter es considerado de suma importancia por los distintos autores que han estudiado el género. Shaw (1914) considera el ala articulada como mas evolucionada, y que esa variacion en organo tan importante como la semilla, sugiere diferencias de géneros, aun- que aclara que en Pinus se encuentran los dos tipos en especies del mismo grupo, Pilger (1926) lo utiliza para separar la~ seccién Sula. Gaussen (1951) considera el ala arti- culada como un caracter primitivo y el ala ad- nata como evolucionado. Concluyendo: Dada la importancia ta- xonomica que tiene el ala de la semilla y por otros caracteres diferenciales, existen suficien- tes razones para considerar las poblaciones geograficamente aisladas de Pinus caribaea Morelet como entidades diferentes, aunque no merezcan el rango especifico. Por lo tan- to se subdivide esta especie en tres varieda- des: P. caribaea var. caribaea de Cuba (tipi- ca); P. caribaea var. hondurensis de Centro- américa y P. caribaea var. bahamensis de las Islas Bahamas. METODO DE TRABAJO Los estudios realizados sobre esta especie, incluyeron: Observaciones en el campo, re- coleccién de material de herbario, cosecha de semillas, y su posterior cultivo. Se re- visO criticamente la bibliografia existente y se solicit6 material botanico e informes a distintas instituciones y personas a las cuales se agradece, especialmente al Dr. W. C. Steere del New York Botanical Garden (N.Y.), 2 la Dra. A. Lourteig del Musée d’ Histoire Na- turelle de Paris, al Conservator of Forests of British Honduras, Mr. A. C. Frith y colabo- radores, y a Mr. C. P. Nielsen de Owens- Illinois of the Bahamas, Limited. En 1957, Golfari en compania del Ing. Carlos Negrotti, enviados por Celulosa Ar- gentina S. A., realizaron un viaje por Nica- ragua, Honduras, Guatemala, Honduras Bri- CARIBBEAN FORESTER tanica, y Cuba con el fin de estudiar esta especie en su habitat y recolectar semillas para su siemibra en Argentina. En 1960, en ocasién del viaje de estudios de las coni- feras latinoamericanas organizado por F.A.O. los autores tuvieron oportunidad de_ reco- rrer pinares de esta especie en Honduras, Honduras Britanica, Cuba, y Bahamas. Du- rante este viaje se recogid abundante ma- terial que se encuentra depositado en el her- bario del Instituto de Botanica (BAB) del Instituto Nacional de Tecnologia Agrope- cuaria (I.N.T.A.) de Buenos Aires. Con semillas de distinto origen se reali- zaron cultivos experimentales en Buenos Aires, Delta, Santa Fe, Tucuman y Misiones (Argentina). Las plantas de dichos culti- vos se estudiaron comparativamente en dis- tintas etapas de su desarrollo. ig i and communications. If only a few references _ a at _ to literature are made, literature citations may ae i J be placed in footnotes. Literature citations © } au Sk pa ro fey - should include the author, year published, ti- irks i tle of the work cited, name of DIRS nee ; . ep i pone ge __ Hanote. ete ra aparait ate f ste should & sent to the coed le texte sous la lig: le numero’ eke ap Leaittute of ropical orestry, at bs Ice / iG _hriytat Me "HPgeD. Naum ike yh Weaatian iro jotes au pied sont usées pour \ necessarily those of the Forest Service. Ar- ie sib aia ‘avaux qué 1 Mom he - ticles published in the Caribbean Forester _be reproduced, en Seclet ee petal sours, SS TAR ES Le eT ‘ e if ee Le “Caribbean Riratee” Siindbehseag’ : _ annuelle qui a été publiée depuis l'année 1938 — Puerto Rico por le Institut de Foresterie oy opique, Service Forestier du Départment _ de cea des Etats-Unis. Cette revue es a laménagement et a utilisation ‘US des forets surtout dans la Sehburas caraibe. He ; ate ar les pages de cette revue les personnes travaillent aux tropiques pi vent etre in- . sur les problemes ponies des fo- et sur les travaux t effectués pour ectu uh, ER Ey a Shy es 4 x AFT Ale Se ths 5] pe he BU Ate " He amt Re latins eae Lo Ghee es Y ae mig { Pai h * im, i iy < % SN \ “