university of Connecticut libraries ' hbl.stx SD 144.C8L4 Studies of Connecticut hardwoods; 3 =1153 00513bbD 3 in -P" O 00 Digitized by the Internet Archive in 2011 with funding from Boston Library Consortium Member Libraries http://www.archive.org/details/studiesofconnectOOIeff YALE UNIVERSITY ■ SCHOOL OF FORESTRY mil E i in no is STUDIES OF CONNECTICUT HARDWOODS THE TREATMENT OF ADVANCE GROWTH ARISING AS A RESl'ET OF THINNINGS AND SHELTERWOOD CUTTINGS BY LOUIS J. LEFFELMAN Research Fellow, Vale l'niv<.-rsity AND RALPH C. HAWLEY Professor of Forestry, Vale University NEW HAVEN Yale Universitv 1925 CONTEN fS Page PURPOSE "l l 111 [NVES1 EGATION 5 Ml 1 HODS OF SI l D\ 7 DESCRIP riON 01 llll' AREAS 1N\ ES lie \ 1 ED 8 A SYSTEM OF CLASSIFICATION FOR THE WOODY VEGE- TATION 9 Grow i m 1. 9 Classification of Growth Forms io Origin and Development of Growth Forms 12 Previous Work on Growth Forms 14 Miscei 1 \m ous Factors 15 THE AMOUNT, CHARACTER, AND DISTRIBUTION OF 1 III ADVANCE GROW III AND OF THE YOUNGER REPRODUCTION 17 GROWTH IN HEIGHT OF THE VARIOUS ELEMENTS COM- POSING THE YOUNG STAND 37 Height Growth of Younger Reproduction 38 Height Growth of Advance Growth 41 CONCLUSH >NS AS TO THE PROBABLE COMPOSITION OF THE FUTU RE STAND AND THE RELATIVE VALUE OF THE INDIVIDUALS WHICH IT WILL CONTAIN 44 The Species in the Future Stand 44 Relative Value of the Growth Forms 45 Relative Value of Advance Growth as Compared with Younger Reproduction 46 Conclusions on the Basis of Site 47 TREATMENT ADVISED TO IMPROVE THE FUTURE STAND 50 ILLUSTRATION- 53 The authors wish to acknowledge their indebtedness to Dr. George E. Nichols, Associate Professor of Botany, Yale University, for helpful suggestions in reference to growth forms and for his aid in photographing the various root systems shown in Figures 3, 4, 5, 8, 9, 10, 11, and 15. STUDIES OF CONNECTICUT HARDWOODS THE TREATMENT OF ADVANCE GROWTH ARISING AS A RESULT OF THINNINGS AND SHELTERWOOD CUTTINGS j\ LOl [S J. 1.1 1 I I.I.MAN AND RAI.1MI C. 1IAWLKY rr KTOSE OF THE INVESTIGATION THE typical hardwood stand with which the silviculturist in Con- necticut has to deal is even-aged in form. The causes which operated in the past to create stands of this character are thoroughly understood and do not require consideration in this study. That even-aged stands, particu- larly when densely stocked and composed of comparatively intolerant species, require thinning to develop the most vigorous individuals and to obtain maximum production, is an accepted principle of silviculture. A- the practice of forestry started during the last quarter-century, initial thinnings and improvement cuttings were made. In many cases the operation was repeated two or more times, at intervals of five to fifteen years. In older stands reproduction cuttings of the shelterwood type some- times followed or were substituted for thinnings. Salvage cuttings of the chestnut leaving the other species (an operation forced by the ravages of the chestnut blight) resembled either thinnings or shelterwood cuttings. As experience was acquired, it became evident that all of these cuttings, thinnings, improvement cuttings, salvage cuttings, and shelterwood cuttings were followed by prolific reproduction of trees and shrubs, either sprouts from cut stumps, root suckers, or seedlings. Even the lightest thinning among the living trees had this effect. The reproduction in most cases originates many years before it is wanted. It remains under cover for long periods, during which many of the indi- vidual stems die. while others are badly injured or deformed. Eventually the old stand is removed by a final shelterwood cutting or by a clearcutting. TREATMENT OF ADVANCE GROWTH The remnants of the reproduction, which originated at intervals during a period of several decades, now are freed and left in a position to dominate all or portions of the area. Young seedlings developed by the later shelter- wood cuttings, or sprouts arising after the clearcutting, must compete with the older (and possibly more undesirable) elements of the reproduction. The early treatment of this young, relatively irregular stand, composed of individuals of varying shape, species (both trees and shrubs), origin, vigor, age, and rate of growth, with the object in view of obtaining the most promising combination for future timber production, constitutes a silvicultural problem of large importance. The authors have studied the problem intensively in the attempt to determine the relative value, as com- ponents of the future stand, of all elements in the reproduction, particularly those which originated prior to the final removal of the old stand. Pre- liminary conclusions are set forth in the present report. The term "advance growth" has been applied in this study to all repro- duction, both trees and shrubs, which originates on a given area prior to the final removal of the old stand. It is recognized that this use of the term does not agree exactly with the terminology adopted by the Society of American Foresters.1 According to the definition adopted by this Society, "advance growth" is recognized as "young trees which have sprung up spontaneously in openings in the forest, or under the forest cover (before reproduction fellings are begun)." It was found that the time of origin of the reproduction — whether it started previous or subsequent to the first reproduction cutting — was not a determining factor in the relative value of this reproduction in the future stand. Moreover, in hardwood stands repeatedly thinned and later repro- duced by the shelterwood method there will always be difficulty in fixing exactly the line of demarkation between the two types of cuttings. For these reasons a broader definition of the term "advance growth" appeared desirable. The study separates logically into five parts : i. A system of classification for the woody vegetation. 2. Amount, character, and distribution of the advance growth and of reproduction arising subsequent to the last cutting. 3. Growth in height of the various elements composing the young stand. 4. Conclusions as to the probable composition of the future stand and the relative value of the individuals which it will contain. 1 Forest Terminology. Terms in Forestry compiled by a committee of the Society of American Foresters. Journal of Forestry, Vol. 15, 1917, P- 7i- TREA l Ml \ l OF ADVANCE GROW l 1 1 5. rreatment advised to improve the future stand. ilk- field of this investigation was restricted to the hardwood stands growing >»n the better drained soils. This excluded swamps and the wetter bottomlands. I in- latter classes of land comprise only a small and relatively unimportant portion of Connecticut's woodlands. Ml rHODS 01 si i h\ Representative areas, where repeated cuttings had been made and ad- vance growth was abundant, were selected near \>u Haven, Conn. Upon these areas the forest cover was studied intensively. The results were checked by less intensive work on other .nets more widely distributed. Measurements on an area basis were necessary in determining amounts and distribution of the different clasM-s <.i vegetation. (Hhrr l'ai tors, such, for example, as height growth, required study on an individual tree basis. The field work occupied the greater portion of one man's time during the period from September, 1924, to June, [925. 'tain data regarding the amount and distribution of the vegetation, the transect method was selected as furnishing better averages than the quadrat method. Continuous transect strips six feet in width were run across the ridges and streams, thus bisecting and sampling all of the main sites and types. A total of -24.600 linear feet of transects were run. In addition twelve one-quarter acre quadrats, distributed over the various sites, were measured. Comparison of these quadrats with the transects wed a difference of only 2 to 10 per cent in the amount and distribution of the vegetation as determined by the two methods. Several smaller quad- rats were used for special studies of the sprout activity of the various growth forms. On the transects and quadrats a complete tally was made of all the iy vegetation according to the classification which is shown later. The I height and age of each individual also were recorded. This involved the measurement of over 43,000 stems. In addition many individuals were sectioned and the ages at intervals above ground counted to enable compu- tation of height growth. Besides the measurements taken on the transects and quadrats, over 4.500 additional stems were measured for age, height growth, and physical condition. Age was determined by cutting just above the root collar. As a practical field problem, it is impossible with the hardwood species definitely to locate the terminal bud-scars which represent the limit of a season's growth. This is true of the oaks especially. TREATMENT OF ADVANCE GROWTH The range of site (swamps excluded) was divided into three classes. Site I indicates conditions for maximum, growth, Site II for average growth, and Site III for poorest growth. The site qualities were determined by ocular observation, using the height growth of trees and shrubs as an indicator. This was checked subsequently by field examinations of the soil. The soil was found to vary in depth in direct proportion to the ob- served or estimated quality of the site. A review of the literature bearing on the subject of advance growth was made. This revealed the fact that very little (and this of a super- ficial character) has been written concerning advance growth. DESCRIPTION OF THE AREAS INVESTIGATED The areas which were studied intensively are located within four miles of the city of New Haven. A tract of seventy-five acres fairly representative of the region in physiography, composition, and character of the forest cover furnished most of the data. (See Figure i.) This area is located upon the eastern rim of the Western Highland.2 Numerous rocky ridges, small flats, and occasional swamps characterize the topography. A layer of yellowish-red glacial till, mixed with rock fragments of chlorite schist, quartz, serpentine, and occasional sandstone boulders of varying size, is the usual soil covering. Oaks predominate in the forest cover. This is typical of the Connecticut hardwood type now that chestnut has succumbed to the blight: Other hardwoods form approximately 25 per cent of the composition. In 1902 the seventy-five-acre tract, with the territory adjoining, was placed under forestry management. A first thinning was made in that year. Additional thinnings and salvage cuttings, for the removal of dead chestnut, followed in 1905, 1908, 1910, and 1913. These extended over all or large portions of the area. Several cuttings, both thinnings and salvage cuttings, were made over small portions of the area in other years of the period from 1902 to 1921. During the winter of 1921 the remainder of the mature timber, at that time seventy-five years of age, was removed. One consequence of the repeated cuttings from 1902 to 1921 was that prolific sprout and seedling reproduction originated on the area beneath the old stand. Indeed, scarcely a single year passed during the twenty- year period without the start of new seedlings or sprouts. Thousands of 2 Gregory, H. E., and Robinson, H. H. : Preliminary Geological Map of Con- necticut. Bulletin No. 7, State of Connecticut Geological and Natural History Survey. 1907. 8 TREATMENT OF ADVANCE GROW I'll these young stems died from natural causes under the partial cover main- tained by the thinned stand. Others were deformed, while still others developed vigorously up to the date oi the final removal of the old .stand. The removal of the remaining older tuns in the winter of 1921 left all this advance growth, of diverse character and condition, in a dominat- ing position. Subsequent to the final cutting, sprouts started from the newly-cut stumps ami seedlings sprang up, thus supplementing the advance growth already present and increasing the total reproduction. (See Figure 2.) These seedlings originated from seeds either derived from the 1920 seed crop on mature trees just felled or Mown in from trees outside the ana. The total reproduction, made up as just described of advance growth plus reproduction originating subsequent to the final cutting, was sufficient to tute a fully Stocked stand. The area afforded an exceptional opportunity to study intensively the relative value of the different elements constituting the reproduction. M ore extensive >tudie>. which, however, included the taking of measure- ments, were made on twenty-nine other areas selected as representative of the Connecticut Hardwood Region. A SYSTEM OF CLASSIFICATION FOR THE WOODY VEGETATION The nature of the problem required classification of the woody vegeta- tion with reference to species, site, age, total height, origin and relative position, shape and thrift of crown. For this purpose, as a prerequisite step to the gathering of data, it became necessary to devise a system of classi- fication which could be used in tallying and measuring all stems: a classi- fication so arranged that it could be applied in bringing out the relative future values of the various individuals. Growth Forms Origin was found to be of importance in influencing the rate of height growth of the individual stem and in determining the chance of its ultimate survival. The term "Growth Form" will be used throughout this report to desig- nate the various types of origin. Considered from this standpoint it is customary to divide woody vegetation into two classes, namely, seedlings TREATMENT OF ADVANCE GROWTH and sprouts. Thus there may be distinguished the '"seedling" growth form and the "sprout" growth form and, as will be demonstrated, several other growth forms. A preliminary survey disclosed the need for improving and clarifying the present classification of origin to permit of a more accurate use under field conditions. Before a satisfactory system of classification on the basis of origin could be established, considerable special field work had to be completed and a review made of the literature bearing on the subject. The importance of origin as a factor influencing survival made the revision of existing definitions and terms imperative. The growth forms recognized by the Society of American Foresters3 are as follows : i. "A sprout is a tree which has grown from a stump or root. (A sucker is a tree growing from a root.)" 2. "A seedling is a tree grown from seed." 3. "A seedling sprout is a sprout resulting from the cutting of a seedling or small sapling. This is differentiated from coppice sprout or shoot because of its subsequent behavior." Using these definitions an attempt was made to identify the reproduc- tion in the field. True sprouts were easily identified in the field, with the exception that an arbitrary diameter limit at the ground had to be estab- lished, in order to separate sprouts from seedling sprouts. Without con- siderable experience it is impossible in the majority of cases to distinguish with certainty seedlings from seedling sprouts. After experience gained through the study of the appearance and characteristics of these two growth forms they may be distinguished with reasonable accuracy provided a care- ful inspection on each individual is made of the stem and region about the root collar. After thorough investigation, a new classification of growth forms was drawn up which, it is believed, will enable quicker and more accurate field identification. This classification is inserted here, and a discussion of the reasons which led to its adoption is given in the following pages. Classification of Growth Forms. 1. A sprout is a tree which has grown from a stump over two inches in diameter at the ground line. (See page 13.) 2. A seedling is a tree grown from a seed. 3 Forest Terminology. Terms in Forestry compiled by a committee of the Society of American Foresters. Journal of Forestry, Vol. 15, 19 17, pp. 91 to 94. 10 TRl'.Al Ml \ l OF \l>\ am l GROW I ll Dormant buds are present at or just below the root collar. (See : ; i lu- roots of the seedling radiate in all directions from the main stem, and it has comparatively rough bark while the single seedling sprout has a smooth bark surface along the entire Length of the stem. 3. A single seedling sprout is a tree with a single stem which has grown from .1 stump two inches 01 less than two inches in diameter at the ground lino. (See page 13.) - gle seedling sprouts have .1 growth rate of two to four feet for the first year, as compared t<> one foot or less in true seedlings. I mpare Figure o with Figure 8.) One or more small partly de- cayed stubs mar the ground line with the hark of the present stem developing a callus around the stub are present always in young gle seedling sprouts. (See Figures 4 to 8.) So far as surface indications go. the roots of seedling sprouts do not radiate in all directions from the main stem. This often may be judged by the swollen I :ie side of the tree. The side from which the new generation originates appears to be free from large roots. (Contrast Figure 3 with Figure 4.) Seedling sprouts (both single and multiple) are characterized by sharper and more pronounced crooks in the main tap root just below the ground line than are found in seedlings. (Contrast 1 igure 3 with Figure 4.) 4. A multiple seedling sprout is a tree with more than one stem, which has grown from a stump two inches or less than two inches in diameter at the ground line. (See page 13.) Multiple seedling sprouts grow nearly as fast as single seedling sprouts, but differ from the latter in having several stems instead of one. The number of these stems varies from two to ten in the young stage. Later this number usually is reduced to a single stem or to two stems. (See Figures 9 to 14.) 5. A root sucker is a sprout from a root. Root suckers were found only in two unimportant species, beech and aspen. An intensive study of the root systems of seedlings, single and multiple seedling sprouts, and sprouts was made, involving the digging up of over 400 plants. The roots of the single and multiple seedling sprouts were much thicker than those of true seedlings. A comparison of the relative health and vitality of the root systems, and the general physical condition TREATMENT OF ADVANCE GROWTH of the tree, indicated that seedlings ranked first, single seedling sprouts next, then multiple seedling sprouts, and lastly sprouts. Origin and Development of Growth Forms. In the beginning all trees in the region originated from seed. Each year thousands of new stems originate in this manner. The other growth forms develop from true seedlings or from one another. (See Figure 15.) The process of development from one form to another may be observed in every hardwood stand. The plant may continue as a seedling throughout life. On the other hand, one of the following calamities may occur and result in the dying back or removal of the aerial stem of the seedling : 1. Drought or winter killing may cause the seedling to die back to the ground line. 2. Mechanical injuries may break or cut off the main stem. (See Figures 9 and 12.) Intentional cuttings are included here. 3. Fires may destroy the aerial stem. 4. Rodents or cattle may damage the seedling so badly that it will die back to the ground line. Any circumstance which causes the death of the aerial portion of the seedling prepares the way for the development of sprout growth on the old root system. Injuries which do not kill the stem down to the ground line leave the individual still a seedling. After the original seedling dies back to the ground line, the process of regeneration may result in the development of any one of the growth forms. Root suckers rarely arise, being produced by only a few unim- portant species. Dormant buds located at or just below the root collar are present in the hardwoods of the region. (See Figure 3.) The removal or death of the stem causes one of the following reactions : (a) A single bud may start to function and produce a shoot to replace the stem of the previous generation. This will develop into a single seedling sprout. (See Figure 15.) (b) Several dormant buds become active, giving rise to the multiple seedling sprout form. (See Figures 9 to 14.) Competition and other environmental factors often reduce the number of sprouts to one. Thus a multiple seedling sprout may turn ultimately into a single seedling sprout. To determine the proportion of stems developing into single seedling sprouts as compared to the multiple form, 100 young 1 RE \ 1 Ml \ I 01 Al'\ Wil I'.KuW I 11 tiers from one to two inches in diameter at the ground line were cul ofl in the fall of 1924. rhe stumps of these trees were inspe< ted in the follow- ing spring. A count showed that -' i per cent oi the total numbei of slumps produced single seedling sprouts while the remainder produced multiple seedling sprouts. Determination why a single bud rather than several buds •iks active is .i laboratory problem, involving a physiological invesl tion of the functions of dormant buds. Where the stump of the original seedling was over two inches in diameter at the ground line, the new shoot (or shoots) would be classified under the sprout growth form, The true basis of separation between (a) sprouts, and (b) single and multiple seedling sprouts, is the root system. Sprouts form a root system independent of that of the previous generation. Portions of the old root system may be incorporated into tlie root system of the new plant, but never the entire old system. The portions of tin- old root system not SO incorporated decay quickly and carry decay back into the heart of the new tree. This accounts for the decay which is characteris- tically found in the butts of sprout trees. Seedling sprouts (both single and multiple) use the root system of the previous generation in its entirety. The old root system is completely en- ■d. lives on and functions as part of the new plant. There is no easy entrance for decay below ground. The stub of the old stem is callused over quickly and completely. In consequence the seedling sprout approaches the true seedling in freedom from butt rot. The ability of the new shoot to utilize the old root system and to callus over the dead stub of the stem depends upon the size of the root system and stem. This varies widely with species and with natural factors. An arbitrary size limit cannot be taken as a fully satisfactory basis of classification. From the practical standpoint an arbitrary diameter limit is necessary, since the extent to which the old root system is utilized by the new shoot cannot be seen definitely without digging around the root system of each individual. In most cases where stems are over two inches in diameter at the ground line the old stub fails to callus over completely before rot enters and the old root system is not entirely utilized by the new plant. Two inches was taken finally as the dividing size limit between seedling sprouts and sprouts. The plant may undergo several calamities at intervals one year or more apart. After each calamity the same process of regeneration is repeated. Where killing back ( particularly by fires) has taken place repeatedly over a period of years, the stems are likely to be spindling and feeble, while 13 TREATMENT OF ADVANCE GROWTH the root system becomes thickened, knotty, and susceptible to decay, with more the appearance of an underground stem than of a root. Under normal conditions, where stems are removed in cuttings or are killed back to the ground at occasional intervals, the process of regeneration from existing root systems into growth forms of both seedling sprouts and sprouts can continue indefinitely without loss of vitality. (See Figure n.) Previous Work on Growth Forms. Growth forms have received only superficial attention from foresters in the past. The presence of a growth form intermediate between a seedling and a sprout has been noted, but only a few writers have tried to describe it. The first attempt to classify this intermediate form is found in a report by G. Frederick Schwarz.4 Under the heading, "Forms of Reproduction," he says : "Reproduction in sprout forests consists mainly of young sprouts, although seedlings find entrance here and there and ultimately grow into the stand. In addition to these two forms there is a third, commonly found throughout the most of our second-growth deciduous forests, which may be said physiologically to stand between the two others. For want of a better name it may be called 'seedling-sprouts.' " Schwarz apparently encountered the extreme type attained by this growth form. He mentions the abnormally thickened root system, the presence of stubs from the previous generations, but does not mention having found specimens which showed a healthy vigorous growth rate. His conclusions are that "Seedling reproduction is limited in sprout forests on account of dense shade, injury and suppression through fallen branches, fires, brows- ing of cattle, nibbling of rodents, etc. Most of the seedlings are ultimately transformed, by repeated attempts at sprouting, into 'seedling-sprouts.' " Another mention of the term "seedling-sprouts" is made by P. L. Buttrick.5 He says that "seedlings killed back, often sprout again. They are then called seedling-sprouts, and it is often difficult to tell them from seedlings. It is the writer's observation that fully half the seedling reproduction in parts of the state consists of seedling-sprouts." His general conclusions are that, if the seedling is burned to the ground line, sprouting results, usually with the development of more than one stem, but that repeated 4 Schwarz, G. Frederick : The Sprout Forests of the Housatonic Valley. Forestry Quarterly, Vol. 5, 1907, p. 134. 5 Buttrick, P. L. : The Effect of Forest Fires on Trees and Reproduction in Southern New England. Forestry Quarterly, Vol. 10, 19 12, p. 13. 14 TRI A l'MI'N r OK Al>\ W'CE GROW in fires finally result in the death of the entire pi. mi. He also brings out the point that the accelerated growth is over in two or three years, and there- after development is that of a seedling rather than a sprout Both Single and multiple Seedling sprouts air produced 1>\ certain coni- fers. Although the names were not used, these growth forms are described accurately in a study of shortleaf pine by W. R. Mattoon.* Similar growth forms develop in pitch pine reproduction and probably in redwood. In European literature, reference to seedling sprouts is made by Bagneris.1 This writer noticed the repeated efforts of a seedling to throw up shoots strong enough to resist forest tires, until finally a single stein develops into a tree. In reference to this fact he says: "Many of our so-called seed- ling trees ni the broadlcavcd species have originated thus." A. C. Cline and C. R. Lockard,8 working with pine and hardwoods in northern Massa- chusetts, have used recently ( 192O a classification of sprout growth forms based on diameter of the stool. According to their terminology seedling sprouts are those arising from stools one-half inch or less in size, small sapling sprouts from stools three-quarters inch to one and one-half inches in size, large sapling sprouts from stools two and three inches in size, small pole sprouts from stools four to seven inches in size, large pole sprouts from stools eight to eleven inches in size, and standard sprouts from stools twelve to twenty-four inches in size. Miscellaneous Factors All trees and shrubs were tallied under their own common names. The one exception was chestnut. This species was not tallied, since it is already practically eliminated from the stand, due to the continued ravages of the chestnut blight. While occasional clumps of chestnut sprouts may be found, they are rapidly being overtopped by the other species. A complete list of the species tallied is given, showing both their common and scientific names. Sargent's nomenclature has been followed in the scientific names of the tree species. 8 MattoON. W. R. : Life History of Shortleaf Pine. Bulletin No. 244, U. S. Dept. of Agriculture, 19 15. pp. 20 to 20. 7 BaGNERIS, G. : Elements of Silviculture, 1882, p. 113. 8 Cline, A. C, and Lockard, C. R. : Mixed White Pine and. Hardwood. Bulletin Xo. S. Harvard Forest, 1925. p. 22. IS TREATMENT OF Scientific Name Populus grandidentata Juglans cinerea Carya cordiformis Carya ovata Carya alba Carpinus caroliniana Ostrya virginiana Betula lenta Betula lutea Betula populij olia Fagus grandifolia Quercus borealis Quercus coccinea Quercus velutina Quercus alba Quercus montana Ulmus americana Liriodendron tulipifera Sassafras officinale H amamelis virginiana Amelanchier canadensis Prunus serotina Acer saccharum Acer rubrum Tilia glabra Cornus florida Fraxinus americana Fraxinus nigra Viburnum acerifolium, L. ADVANCE GROWTH Common Name Large-tooth Aspen Butternut Bitternut Hickory Shagbark Hickory Mockernut Hickory Blue Beech Ironwood Black Birch Yellow Birch Gray Birch Beech Red Oak Scarlet Oak Black Oak White Oak Chestnut Oak White Elm Yellow Poplar Sassafras Witch Hazel Shad Bush Black Cherry Hard Maple Red Maple Bass wood Dogwood White Ash Black Ash Maple-leaved Viburnum Site was a factor of primary importance in the classification. Three site classes, I, II, and III (as mentioned previously), were recognized. On the transect lines the extent of each site quality was noted, and the vegetation tallied separately by sites. Quadrats were located so as to sample a single site. The age of each individual stem was ascertained. In the final tables only two general age classes were recognized : (a) all stems one to four years of age, (b) stems over four years of age. This division served to differentiate 16 • REA l MEN l I >l Al>\ \\* l GROV\ ill between the reproduction originating subsequent to the final cutting, and the advance growth. Since the final cutting occurred in the winter of 1921, all reproduction originating later was four years old or less when tallied in the fall >>t 1924. One-half foot height classes were employed in tallying the vegetation. The total height of each stem was recorded to the nearest half I The relative position «•! its crown is of vital importance in judging tin- probable future value of the individual stem. For this reason each stem classified as either free or overtopped. The crowns were further classified on the basis of shape under three divisions: ll\ :.'.'- crowns which are well rounded and pro- portionate to th • length of stem. 1 Set- 1 inures 16 and 17.) Umbrella tops); crowns flat on top which are thin, fairly wide and extend only one-eighth to one-quarter of the length of the main stem. (Wolf tiers) ; crowns formed by large lateral branches which begin low down on the stem, extend to a relatively great distance, and often give the tree a bush-like appearance. This applied only to advance growth, not to reproduction which started after the final cutting, since the latter was too young to show differentiation into a variety of crown shapes. The presence or absence of injuries result- ing from the attacks of either insects or fungi also was noted for the advance growth. At first an effort was made to classify all stems on the basis of relative . g r. This additional complication finally was deemed unnecessary, since the division of the stems into free or overtopped and into well- formed, flat- topped, or abnormally-spreading crowns gave a direct indication as to the health and vigor of the plant. THE AMOUNT. CHARACTER. AND DISTRIBUTION OF THE ADVANCE GROWTH AND OF THE YOUNGER REPRODUCTION Before consideration of treatment of the advance growth a knowledge of the amount, the character, and the distribution of the different elements on the areas to be treated is essential. Tables 1 to 4 summarize the field data secured which bear on the subject. Results are shown separately for each of the three important Site Qualities I, II, and III in Tables 1 to 3. ndensed summary of the values on each Site and for all three Sites combined is given in Table 4. From these tables of basic data Tables 5 to 21 have been compiled to illustrate particular points. O O t— i H U t> P o p* Cm W w K H ft O pq H n P4 < u Q H O H o C a CO 1 i ■ O o s § s CO IN ■*. 5 5 o &i ■?• >, ■?. 6> . <» ■*. I* H ^ a .tj a pq * ^ o pq w PP > g v- <3-pqpq "^ *"> — ts " r^ \r\ Q v> o N vo ro - f> t IC e tv in in in M «*> N -i T m 1 in in c , <*-■> " 1- VO o w-, in iO -r 00 in Q T m <^ tN « T ro K " •O ts ance Over- topped o> 3 to O ? ■« !i *• j: Is. oo K i "9 ■ productio Ovet ■ O ts m 1/1 tv t fo !* »• O - t n »" - N "" o> - O ts. l<5 X " m N -r «• 0> ts I«J ". ^_ N m N £ w ^ N in *» 10 sprou am c wth topped „ -t in 1^ X <♦ N ts. _ o 'o S: ts vo <*> U-. N VO -* m 0 o 2 !-. ro vO m ^. c M ts . -- s w •_ r 00 5 . N - v c 5 § 8 "^ ■? c •- N >o (^ f« l"J a S — t^ c V) [» w VO v. © - ■ -= -- - w •• ^ N •* rs. Ov o W M oc "5 v ■- ;- -to £ 1 1 o s : w. o VO C 00 O M vo ; -= v5 S KJ — o> M o f« -t N « o H - - w VO "T i - ■* W u) t ^? c - c •? M ts. T c £ N in £ vo r^ ^ « H 00 in . ■« ^ ■- O ** c «» - <* ts U -^ :- s- * = r. - - = to a ■g — Q •1 w t O -r VO C T ■r> _ • "W 5 •» » : - tx « X ** 7 5 VO - c VO »«Oj M ~ - c f) 5 5 v> C "". — m *t >© H X "♦ in VO C Kl n o o 'J "* ts n E r< - ■ N oo C >> 5 a t?. !r •f. a ~ 9 '- G i z 6 -3 Ti N r « ui z S X ^ K > ^ m O O o I— I H U Q O P-. w w W H O W H O O o s &H & § § O 5 1 8 i? 1 si ° i ^ *- s ■? o £ ^ & >. 5. »o 3 5 i? *< o ^ 5; H ©\ o <* t cq to ■tf VO vo t~* in cs vo 00 to CO to C\ «n to tv) M to vo u-i cvi VO tO >* 00 o o o to 00 vO o to tvi o v© t^ O H cq 0\ N 0\ t^ C7\ O tx hi m to o LO ii vo tx N U") ti o> o> in "t Tf o\ CO ii to i-i in tq vo to to On M h M vo m O Oi "l n DO « ^- 00 N o CO 0\ to o tx o to VO o o VO o\ IX to VO VO o\ to Ov o tvi t^ Ov (^ -fi P-< tn d 3 rt S* CO CO (4 « H h Ih -3 "S ° § r2 ° Ui>.Sc5'-;^'"'— ■ i— i -s iJ ■— •>; 6 All growth forms vo 0 tv. tx tx - vC - (^ O «n 0 o> vO CO CO N co VO M w w __ o u-i N N CO H VO CJ ~ — \n M "T K Is .• "O w '- 00 V, -« O 0 a s 1 3 § * CO _ CI (O VO .■ ^ k| CO CO "t i § s Ol H «>. co e> o> v. J. M O »> u, 10 a <0 „ VO 00 CI vo M 00 tv 1^ t-i ~ CO «•• 3 .• ■« O »■ S — 5» VO »1 V* ^ 1 • a. t 0 o> 0 - - V • o> 5 In. ; ~ ** v> | : «. <0 O X 00 -■ O 3 s £ 0 fi tT \o CO In In Vj VO ^ c a vo 0 rx O ■f O O M CO ■^ :£ ^ Tt C. ri — 1^ VO 00 VO O 2 *^ CO - ro M O. H "t E f« "t N £ 8 * J a H c « 3 a H N. O co -r VO - s — CO £ N VO •- S e 3 "o — t- w •. N VO 00 ts. m \n CO "t * •t VO '-. «* > n n f) O co O »^ O > - t Ol ~- d vo 0 t to O 00 t M m In. t>. * CO — 1/-. to r^ O tN £ N M CC H IO , "H i. c ci Ol CO '- s- « 5 * s> «. c< s* 5 a ^ - ■* "O Js -~ -_ 2i ^ 01 vo CO -t « U, VO - . 13 R *• •- m m C '1 VO k. -8 5 «. S ■*• 6 4k, ? I O 5 M ft "i N - - -r — -r t^ c It ° i: h, g B9 -r - — S1 "7" BQ V g g £ n **1 •- ■- z z c- 1 -: 1 2 S *3 a ■z X •C ~~ « x - 5 — ^* <- ■- w H i— i in £ O O I— I H U £ Q O P-. w Pi! H W H fn CO O 3 £ P< -< \o ""> t*» ■* o\ m M N t^ ■* ■* o\ "-> co ■<*• "^ N M 00 Oi 00 M ■* c^ M cq -M M tJ -^ 3 «o * W CO c< -t co >+ o CO t^ IT) VO t co ■* CO t^ u-> * N I>1 « ^3 h £ A u .q o ji is PQ en o i> u ^ x< ~* *-* mr* _i M ^ ^ <-> 1, ^ "2 ^ ,3 O •■=• pqpqpqO^mQK - i— i Z : y. o — — _ - o U - < C < E h O — 3 ?.? *• ^- a; •t- si - to . ^2 - ,~ * v5 S * 8 „. § 2: * a « O « * - - ,~ ** !•§ 2 s « SO, 3> = 1 ° - to f, :- ^ 9 = ~ c O 1 -t N •t N N N fN c o ~ ri c — ' - S< GO - % " - i £ 0 - -- 2 T3 - — .- — Q Q < PQ H CO W H i— i CO £ O £ O i— i H U 0 Q O e4 PL. w CO P4 w n w s a,Si^ ^ ^ « r s? ■Q- a, 8 ft, "« 'S a s ^ >h ft, 8£ ft. 8 "fe- ci; 5 § £ S£ C3, CO VO CO CO CO t^ in to CO c» O co CO co O 0* PI CO CO 4 £ m w V, b J2 2 1 ° as '4-; O O ■a ^ o o cS +2 O O TREATMENT OF ADVANCE GROW I'll The situation on each site merits individual discussion, and will thus be considered beginning with Site l. Site I. The young growth on Site 1 is distributed between approximately twenty-five species of trees and woody shrubs, rhe white, scarlet, and red oaks, while ash. soft maple, dogwood, and blue beech are all abundant \\ ody shrubs, with viburnum predominating, form an important pan oi the cover. A dense stand, averaging over 10,000 stems to the acre with numerous species well represented, is characteristic. The number of stems per acre of each species of tree and shrub is shown in Table i. To bring out more vividly the actual situation all species of trees and shrubs were combined into three groups as follows: A. The Oaks: comprises red. white, scarlet, black, anil chestnut oaks. B. Other Hardwoods: contains hickory, red and hard maples, black, yellow, and gray birches, black cherry, tulip tree, beech, butternut, white and black ash, basswood, large-tooth aspen, elm, sassafras, blue beech, ironwood, shadbush, and dogwood. I'. Woody Shrubs: includes viburnum, witch hazel, and hazel. TABLE 5 SHOWING THE AMOUNTS EXPRESSED IN PER CENT OF THE TOTAL NUMBER OF STEMS FORMED BY OAKS, OTHER HARDWOODS, AND WOODY SHRUBS ON SITES I, II, AND III Site I Site II Site III Spec Per cent Per cent Per cent Oaks 24 46 59 Other Hardwoods 45 29 26 Woody Shrubs 31 25 15 Total 100 100 100 This division, which is applied not only on Site I but on the other two sites also, corresponds roughly to the silvicultural value of the different species. In general, the oaks are to be favored. The other hardwoods are likely to be of secondary importance or classed as inferior species, while TREATMENT OF ADVANCE GROWTH the shrubs are distinctly weed species. The percentage of the stand formed by each of these divisions is given in Table 5. For comparison, percentages for the other two sites are included. It is evident from this table that the shrubs and a variety of hardwoods other than the oaks compose a larger proportion of the stand on Site I than on Sites II and III. The vegetative cover on the area fell into the four growth forms, seed- lings, single seedling sprouts, multiple seedling sprouts, and sprouts. Table 6 indicates the amount of each growth form in the three groups of species. TABLE 6 SHOWING FOR SITE I THE AMOUNTS OF THE DIFFERENT GROWTH FORMS EXPRESSED IN PER CENT FOR EACH GROUP OF SPECIES Species G r 0 wt h Forms Single Multiple Seedling Seedling Seedlings Sprouts Sprouts Sprouts Total Percentage of total stand Oaks 28 28 36 8 100 Other Hardwoods 34 19 34 13 100 Woody Shrubs 58 0 42 0 100 The small percentage of sprouts is noteworthy. Seedling sprouts pre- dominate, but a large proportion of seedlings are in evidence. The woody shrubs have a much higher percentage of their stems in the seedling growth form than do the oaks and other hardwoods. Of the growth forms represented, the seedlings, single seedling sprouts, and multiple seedling sprouts are of higher future value than the sprouts. It will be seen that 92 per cent of the oaks and 87 per cent of the other hardwoods are of these better growth forms. For best future prospects a stem, no matter of what species or growth form, must have a free position. In other words, it must not be over- topped by one or more stems which have secured a dominant position. In 26 TRl'A I Ml \ 1 OF Al>\ AMI GROWTH Table 7 the percentages of the stems of each growth form and group of species occupying a free position are given. The sprouts, due to their greater height growth in early youth, have the highesl proportion of free stems. There is not much difference between seedlings and seedling sprouts. The woody shrubs have .1 slightly lower percentage free than the oaks and other hardwoods. TABLE 7 SHOWING PERCENTAGE OF EACH GROWTH FORM GROl V OF sri Vll s OCCUPYING A FREE POSITION ON SITE I AND Sp*t Growth F n r ra j Mings and Sir. Multiple Seedling Seedling S eedling Sprouts Seedlings Sprouts Sprouts Combined Sprouts Percentage occupying l free position < l,k> 54 62 57 58 88 Other Hardwoods 6i 79 75 70 90 j Woody Shrubs 5^ 59 57 A further division was made into (a) advance growth and (b) repro- duction arising subsequent to the final cutting. The latter will, for the sake of brevity, be termed "younger reproduction." On the areas inten- sively studied, where the data given in Tables i to 3 were gathered, the final cutting had taken place 4 years previous to the investigation. Con- sequently all stems 4 years old or younger were classed as younger repro- duction, and the stems over 4 years of age as advance growth. The advance growth ranged in age from 7 to 22 years and in height from 5 to 28 feet. None of it was over 6 inches in diameter at breast high. The reproduction arising subsequent to the final cutting ranged from 2 to 14 feet in height and from 1 to 4 years in age. (See Figure 2.) The relative amounts of the two classes are shown in Table 8. 27 TREATMENT OF ADVANCE GROWTH TABLE 8 SHOWING RELATIVE AMOUNT OF ADVANCE GROWTH AND YOUNGER REPRODUCTION ON SITE I Reproduction arising subsequent Advance to the final cutting Species Growth {younger reproduction) Total Percentage of the total stand Oaks 35 65 100 Other Hardwoods 14 86 100 Woody Shrubs 100 100 All Species 15 85 100 Younger reproduction predominated over advance growth in both the oak and other hardwood groups. In the oaks there is a large proportion of advance growth. In order to bring out how much of the advance growth and younger reproduction of the principal growth forms is free, Table 9 is presented. A larger proportion of the advance growth than of the younger reproduction is in a free position. This is a result of their difference in height and age. TABLE 9 SHOWING THE PERCENTAGES OF ADVANCE GROWTH AND YOUNGER REPRODUCTION OCCUPYING A FREE POSITION ON SITE I Advan :e Growth Younger Reproduction Species Seedlings and Seedling Growth Forms Seedlings and Seedling Sprouts Sprouts Sprouts Sprouts Percentage occupying a free position Oaks 70 88 51 87 Other Hardwoods 89 100 67 87 Woody Shrubs 56 28 TRKAT.MKN I' O !•" AI>\ A\iT CROW 111 Nearly all of the reproduction has excellent form and is of a desirable character. (See Figures 2, 10, and ty.) The exceptions to this rule are found : (a) in the case of the suppressed stems already dominated by other elements of the reproduction. This situation needs only passing comment, since it is merely an example of the natural struggle for existence which should take place in every young stand. (b) In the case of certain older individuals in the advance growth, which were suppressed for years previous to the final cutting by the trees of the previous generation. Such individuals are likely to be found now in a dominant position and to have fiat-topped crowns and crooked stems. (c) In the case of other individuals, in the advance growth which had exceptional opportunities to develop rapidly without side crowding. These individuals are likely to have crowns of abnormal spread and with rela- tively heavy branches extending down to the ground. In measuring advance growth, all stems were tallied on the basis of the form and character of their crown and bole into one of three classes: trees with well-formed, with flat-topped, or with abnormally-spreading crowns. Table 10 shows for Site I the results of this classification. TABLE 10 SHOWING THE CHARACTER OF THE CROWNS OF ADVANCE GROWTH EXPRESSED IN PERCENTAGES OF THE NUMBER OF STEMS IN EACH GROUP OF SPECIES ON SITE I Species Well-formed C r oi' n Character Abnormally- Flat-topped spreading Total Per cent of total number of stems Oaks Other Hardwoods All Species 82 51 68 3 15 12 37 7 25 100 100 100 The proportion of poorly formed stems in the oak group is small, but for the other hardwoods amounts to 49 per cent of the stems. A general average of all tree species reduces this to 32 per cent. The possibility that 29 TREATMENT OF ADVANCE GROWTH many of these flat-topped and abnormally-spreading trees may grow into trees of considerable future value will be discussed later. The distribution of the various elements of the reproduction is uniform over the area whether species, growth forms, condition of crown, or other factors involved are considered. In Tables 5 to 10 the relative number of stems expressed in percentages has been used as the basis for bringing out the distinctions between the different classes in the reproduction. By properly applying the percentages contained in these tables it can be shown that there are at least 1100 oak and 3000 other hardwood stems per acre standing in a free position, of the more promising growth forms (seedling and seedling sprouts) and with well-formed crowns. This is a sufficient number of stems fully to stock Site I areas. An expression as to the number of stems per acre is less significant than one which indicates the percentage of the land area occupied by each of the various classes of stems. This is most difficult to determine exactly because of the small size, large number per acre, and intimate contact of the individuals dealt with. The areas can be only approximated, mainly on the basis of observation and judgment. The values in Table 11 have been arrived at on the basis of careful observation and judgment, and are offered as approximate averages of the area occupied on each of the three sites by various classes of reproduction. TABLE 11 SHOWING PERCENTAGE OF AREA ON EACH SITE OCCUPIED BY WELL-FORMED, FREE SEEDLINGS AND SEEDLING SPROUTS, AND BY OTHER CLASSES OF REPRODUCTION Site I Site II Site III Percentage of total area Oaks, well-formed, free seedlings and seedling sprouts 20 35 35 Other Hardwoods, well-formed, free seedlings and seedling sprouts 30 25 20 Sprouts, all species, and poorly formed seedlings and seedling sprouts 25 25 35 Woody Shrubs 25 15 10 Total 100 100 100 30 TRI \ I Ml A I 01 Al>\ WiT GR< 'Will on Site l 50 per cent "t the area is occupied qov bj oak ami other hardwood stems "t good character, while half the area is covered by wood} shrubs or less promising classes "t oak and other hardwoods. Site 11. A- contrasted with Site 1. the predominance of chestnut oak (see Tables I and a) 1- the outstanding Feature on Site 11. Oaks .is a whole have nearly doubled .is compared with Site 1 (see Table 5). ami here form 46 per cent of the staml. While practically the same species <>i trees ami v. dy shrubs occur as on site 1, the hardwoods other than oak an- less prominent, forming only 29 per cent, and the woody shrubs have de- creased to 25 per cent The total number of stems per acre is less than i. This amount provides a dense, fully stocked stand. In the oak group white oak ami scarlet oak follow next in numbers to the chestnut oak. Red maple and dogwood are most numerous in the other hardwoods group. Viburnum composes nearly So per rent of the woody shrubs. Table [2 gives the percentages of the different growth forms within each group of species. There is very little difference between Sites I and II in this respect 1 see Table 6), with the exception that woody shrub seedlings are less numerous, and multiple seedling sprouts more abundant on Site II. TABLE 12 SHOWING FOR SITE II THE AMOUNTS OF THE DIFFERENT GROWTH FORMS EXPRESSED IN PER CENT FOR EACH GROUP OF SPECIES Spcc ics G Single seedling r 0 ic t h Forms Multiple seedling Seedlings sprouts sprouts Sprouts Total Perce itage of total stand Oaks ■2" 35 30 8 100 Other Hardwoods 30 15 45 10 100 i Wood v Shrubs 38 62 100 Table 13 states the percentage of each growth form occupying a free position. A point of interest is the much lower percentage of woody shrubs 3i TREATMENT OF ADVANCE GROWTH in a free position on Site II — 42 per cent for all growth forms combined — as contrasted with 57 per cent on Site I (see Table 7). TABLE 13 SHOWING PERCENTAGE OF EACH GROWTH FORM AND GROUP OF SPECIES OCCUPYING A FREE POSITION ON SITE II Species Seedlings Growth Forms Single Multiple Seedlings and seedling seedling seedling sprouts sprouts sprouts combined Sprouts Percentage occupying a free position Oaks Other Hardwoods Woody Shrubs 49 60 47 59 57 54 70 67 65 38 42 83 85 The proportion of advance growth to younger reproduction remains practically the same in the oaks, but in the other hardwoods is nearly double that found on Site I. (See Table 8.) Table 14 shows the relative amount of advance growth and younger reproduction on Site II. TABLE 14 SHOWING RELATIVE AMOUNTS OF ADVANCE GROWTH AND YOUNGER REPRODUCTION ON SITE II Species Advance Growth Younger Reproduction Total Percentage of the total stand Oaks Other Hardwoods Woody Shrubs All Species 3,2 26 22 68 74 100 78 100 100 100 100 In Table 15 is shown the percentage of advance growth and younger reproduction which stands in a free position. Approximately three- 32 TREATMENT OF ADVANCE GROW ill quarters of the- advance growth and one-half of the younger reproduction of seedling and seedling sprout form is tree. 1 \1!I.K 15 SHOWING Mir PERCENTAGE OF A.DVANC1 GROWTH AND LOUNGER REPRODUCTION WHICH [S OCCUPYING A FREE POS1 [TON ON Mil 1 1 Younger Reproduction Utt ' III S llinffs and and Sprouts seedling sprouts Sprouts ■ entage occupying a free position Oaks 71 go 45 81 Other Hardwoods 79 96 55 81 - • ubs 4 1 The classification of advance growth on the basis of crown development, s given in Table 16. indicates that over two-thirds of it is well formed. Trees with abnormal crown spread are relatively somewhat more abundant Site II than on Site I. (See Table 10.) TABLE 16 SHOWING CHARACTER OF THE CROWNS OF ADVANCE GROWTH EXPRESSED IN PERCENTAGES OF THE NUMBER OF STEMS IN EACH GROUP OF SPECIES ON SITE II Spe Crown Character Abnormally- Well-formed Flat-topped spreading Total Percentage of total number of stems Oaks Other Hardwoods All Species 64 2 34 66 4 30 65 3 32 [00 100 100 33 TREATMENT OF ADVANCE GROWTH The distribution by species is not so regular on Site II as on Site I. On the former, chestnut oak often occurs in fairly pure groups. Scarlet oak to a smaller degree has the same tendency. The other species occur in scattered distribution. Approximately noo oak and iooo other hardwoods with free, well- formed stems of seedling and seedling sprout origin occur on the average acre on Site II. They occupy 60 per cent of the area (see Table 11), woody shrubs occupy only 15 per cent, while seedlings and seedling sprouts of undesirable character, together with sprouts, have possession of the re- maining 25 per cent of the area. Oak seedling and seedling sprouts alone cover 35 per cent of the area as compared with 20 per cent on Site I. Site III. Nearly as many species are represented on Site III as on the other two sites, but in far different proportions. Table 3 gives the distribution of stems by species and growth forms. Chestnut oak is the chief species and forms even a larger proportion of the oak group and of the total stand than on Site II. Thirty-five per cent of all stems are chestnut oak, which dominates the stand. White oak and scarlet oak rank next in number among the oaks. Red maple and blue beech are the best represented among hard- woods other than oak. Viburnum still remains the chief woody shrub, but greatly reduced in numbers and importance as compared with Sites I and II. Fifty-nine per cent of the total stems are included in the oak group, 26 per cent in the other hardwoods group, and 15 per cent are woody shrubs. With the change from Site I to III the oaks have more than doubled in relative numbers, while woody shrubs and other hardwoods have decreased nearly 100 per cent. Total number of stems per acre is approximately 5000. This appears to be a small number when the 16,000 stems per acre on Site I are con- sidered. On the other hand, the number is ample for full stocking and must within a few years be substantially reduced in the struggle for existence. Table 17 gives the distribution of the four growth forms. In studying this table in connection with similar tables (6 and 12) for the other sites, there may be discerned : as the site becomes poorer, a decrease in the proportion of seedlings, an increase in the proportion of seedling sprouts, and a nearly constant ratio of sprouts. 34 l Kl \ I Ml\ I 01 \1'\ \\H GROWTH I \i:l I' 17 SHOWING FOR SITE IIJ MM wit u \ I S 01 rHE DIFFERENT C.Kow m FORMS EXPRESSED l N PER CEN1 FOR l \ill GR< >i r ( '1 SP] til- "i i Mull itliJS Sfn ■ Pat total stand O.iks to -=, A<> 9 100 Other Hardwoods .•: "> 47 15 100 iy Shrubs 33 67 IOO A higher percentage of free stems, in all three groups of species, was found on Site III than on Sites I ami II. Tin- values in Table (8 wheo compared with those in Tables 7 and 13 illustrate tin- point. The explana- tion "f this situation probably lies in the much smaller number of trees per acre on Site III. TABLE 18 SHOWING PERCENTAGE OF EACH GROWTH FORM AND GROUP OF SPECIES OCCUPYING A FREE POSI- TION ON SITE III Species Growth Forms Seedlings Single Multiple and Seedling Seedling Seedling Seedlings Sprouts Sprouts Sprouts Sprouts Percentage occupying a free position Oaks 50 77 70 68 87 Other Hardwoods 83 83 76 85 Woody Shrubs 55 75 68 35 TREATMENT OF ADVANCE GROWTH Site III has a much higher percentage of advance growth in the repro- duction than either of the other two sites. The values are given in Table 19. Compare with Tables 8 and 14. TABLE 19 SHOWING RELATIVE AMOUNT OF ADVANCE GROWTH AND YOUNGER REPRODUCTION ON SITE III Species Advance Growth Younger Reproduction Total Percentage of the total stand Oaks Other Hardwoods Woody Shrubs All Species 53 3i 39 47 69 100 61 100 100 100 100 A large share of the seedlings and seedling sprouts in both the advance growth and the younger reproduction occupy a free position. Table 20 gives the percentages for each class. TABLE 20 SHOWING THE PERCENTAGE OF ADVANCE GROWTH AND YOUNGER REPRODUCTION WHICH IS OCCUPYING A FREE POSITION ON SITE III Advance Growth Younger Reproduction Species Growth Forms Seedlings Seedlings and Seedling and Seedling Sprouts Sprouts Sprouts Sprouts Percentage occupying a free position Oaks 72 92 62 85 Other Hardwoods 93 95 7i 80 Woody Shrubs 68 36 l'Ri.A i mi:\ i 01 \h\ \\i i GROWTH In the adv. unc growth Sj per cent of the oak group and 42 pei cent of the other hardwoods group are well formed, rable 21 shows the dis- tribution by character of crowns. TABLE 21 SHOWING CHARACTER 01 Mil CROWNS 01 ADVANCE GROWTH I XPR1 SSI D IN PERCENTAGES 01 Mil. M Mm R 01 STEMS IN 1 m 11 GR01 P 01 CIES ON sm ill Abnormally- tprtading ./ number oj Oaka Other Hardwoods All Species 8a 6 . _• 4- 31 -r 64 11 a s 100 100 1 00 The chestnut oak is distributed over all parts <>f Site III. In some places this species forms solid blocks, in others it occurs in mixture with the other trees and shrubs. The stand of reproduction on the average acre on Site III includes at least 1100 oak (principally chestnut oak) and 500 other hardwoods, all free, well formed, and of seedling sprout origin. As a conservative estimate 55 per cent of the area is occupied by these 1500 trees. Table 1 1 shows the area occupied by each group of species. GROWTH IX HEIGHT OF THE YARIOTS MS COM- POSING THE YOUNG STAND In the preceding pages the amount, character, and distribution of the reproduction now on the ground has been described. It has been shown that the better species and better growth forms now occupy a large portion of the area. The presence and relative importance in the reproduction 37 TREATMENT OF ADVANCE GROWTH stage of given elements in the reproduction is not necessarily proof that these elements will maintain the same relative position in later stages of the stand's development. The value of advance growth or any other element in the reproduction is contingent more upon its relative position and importance in the mature stand than during the reproduction stage. Given the amount, character, and distribution of the reproduction, height growth more than any other natural factor will determine the final relative position and importance of each element now present. For this reason it was essential that height growth should be investigated. Every stem on the transects was measured to determine its height growth. However, it was deemed unnecessary to show in this report the height growth of all the species growing on the area. Instead, representa- tives of each of the three principal groups of species — namely, oaks, other hardwoods, and woody shrubs — were selected. These selections were made on the basis either of present abundance on the area, or of a rapid rate of height growth. Within the oak group measurements are presented for each species; namely, black, chestnut, red, scarlet, and white oaks. Among other hardwoods, red maple and hickory were selected — the former because of its abundance and because it was the fastest growing species of its class; the latter because, although only sparsely represented, nevertheless it ap- peared to be a persistent companion of the oaks. Taken together, the oaks, red maple, and hickory predominate in the upper canopy. In the third group, viburnum was selected because it was more abundant and had a faster rate of height growth than the other woody shrubs. The height growth of younger reproduction and that of advance growth were kept separate, as well as that of each of the various growth forms. Data were computed for each of the three site classes. Height Growth of Younger Reproduction The best opportunity to compare directly the height growth of the differ- ent species is found in the case of younger reproduction. All of this has come up on cut-over areas in full light and serves as an excellent expression of the comparative ability in rate of height growth possessed by the indi- vidual species. The results are shown in Table 22. Each figure in this table is the average for fifty dominant stems of the particular species and growth form. The mean annual rate of height growth for stems four years of age is given. 38 1 MM E 22 SHOWING HEIGHT GROW ill OF YOl N"G1 R REPROD1 CTION BY SL II', STKCIKS, AND GROW 111 1 ORM . |V.< Mill: .iii<; v all ings HlS -.itlllS S in I Oaks k Oak .90 I.63 1.85 .-.in 1 '.j Chestnut o.ik .98 t.75 I.98 a. S3 i.8a Red Oak I.03 I.98 2.60 1.88 - irlei Oak .00 1-35 1.68 a.38 [.58 White Oak I.40 '•5 5 2.00 1 .46 Other Hardwoods Red Maple ■97 I.9S I.85 a.43 1.80 1 1 i. h •9S 1.63 i-55 2.08 «-55 W< ody Shrubs Viburnum .68 •95 SITE II Oaks Black Oak .80 1.38 1.50 1.93 1.40 Chestnut Oak .88 1.40 1.83 2.35 1. 61 Red Oak .88 1.60 1-73 2.15 1-59 Scarlet Oak .80 1. 10 1-53 2.08 1.38 White Oak .80 115 1.23 1-73 123 Other Hardwoods Red Maple .88 1.68 1-73 2.23 1.63 Hickory .85 i-55 1.40 1-93 1-43 Woody Shrubs Viburnum •53 • 75 SITE III Oaks Black Oak • 70 1.08 1.28 1.48 1.13 Chestnut Oak .80 1.40 1.83 2-35 1-59 Red Oak • 75 1. 18 1-35 1-73 1-25 Scarlet Oak .70 .98 113 i-55 1.09 White Oak .60 .88 i-i5 1.50 1.04 Other Hardwoods Red Maple ■73 i-i5 123 1-75 1 .21 Hickory •75 LIS 1. 18 1.68 [.19 Woody Shrubs Viburnum .40 •65 Each average figure is based on 50 four-year old dominant stems. TREATMENT OF ADVANCE GROWTH This table brings out in striking manner the difference in rate of height growth of the four growth forms. In order of rapidity they range from sprouts as the fastest, through single seedling sprouts and multiple seed- ling sprouts, to seedlings as the slowest. This relation is independent of site. Only three sets of values in the table are contradictory, and these exceptions serve simply to emphasize the rule. They occur in the case of red maple on Site I, and hickory on Sites I and II, and apply only to single seedling sprouts as contrasted with multiple seedling sprouts. Mul- tiple seedling sprouts in these exceptional instances show a slightly higher growth rate than single seedling sprouts. The more rapid growth of a seedling sprout as compared with a seedling can be explained on the basis of the larger root system of the former. This gives the seedling sprout a greater absorbing area and provides a store of reserve food material. Forced growth takes place and continues until the aerial stem or stems are large enough to utilize fully the excess food supply in the roots. As a result, the growth approximates that of a sprout rather than that of a seedling. The greater number of stems dependent on the same root system accounts for the somewhat slower growth of the multiple as compared with the single seedling sprouts. ( Compare Figure 1 1 with Figure 4. ) On all sites, red oak, chestnut oak, and red maple are the three fastest growing species. Hickory, black oak, and scarlet oak grow at a somewhat slower pace, while white oak is the slowest of the tree species in the list. Viburnum comes last with a rate of height growth approximately two- thirds that of the white oak. The relative position of the species in the first two classes is influenced by site. On Site I red oak slightly exceeds chestnut oak in height growth, while chestnut oak in turn is just above the red maple. There is less than 5 per cent difference between any of the three. The desirable species, red oak and chestnut oak, should be able to maintain their position in competition with the maple. The black and scar- let oaks grow in height better than the hickory on Site I and less vigorously than the maple. On Site II the height growth of red oak, chestnut oak, and red maple is nearly identical. While irregular fluctuations in different growth forms can be noted, the averages for the three species differ by only 0.04 of a foot. Hickory on Site II grows a little faster than the black and scarlet oaks. Chestnut oak is the most rapid growing species on Site III, with a rate more than 20 per cent above its nearest competitor, red oak. Maple is 40 rREATMEN r 01 ADVANCE GROWTH slightly belov red oak, Hickory does Dearly as well on Site ill as red maple. Black o.ik. scarlet oak, and white oak follow in the order named, The data in rable 22 refei specifically only to younger reproduction four years or less in age. 1 he question naturally arises whether the dif- ferences in rate of height growth found for the various growth forms and species will continue as the stand grows older. Studies made in older stands indicated that the relative rate of height growth for the different ies remained approximately the same throughout life, but that for different growth forms decided changes took place. The conclusion was reached thai in the development of the average stand the relative growth rates of the different growth forms constantly vary as compared with one another, in such a manner thai ultimately seedlings, single and multiple seedling sprouts, and sprouts all attain equal total heights and from that time on continue to grow in height at the same rate. Before arriving at this conclusion typical specimens of each growth form were selected, felled, and analyzed to determine height growth. In stands twenty years old. single seedling sprouts were found to have approximately the same total height as sprouts. At thirty years, single and multiple seedling sprouts ami sprouts were of the same total height, with seedlings three to six feet below the level of the other growth forms. After the fortieth year no essential difference in total height or rate of growth of the four growth forms could be discerned. Why the relatively rapid growth of the sprout should cease and the slow growth of the seedling become more rapid within such a short span of years is not known with certainty. Possibly the presence of decay in the sprouts may be of importance in this connection. Twenty-eight per cent, even of the young four-year old sprouts, showed traces of decay which had entered from the old decaying stump or roots. No evidence of such injury was noted in either single or multiple seedling sprouts. In seedling sprouts, a complete fusion usually results between the new growth and the old root system of the previous generation, effectually preventing decay. Indeed, a single seedling sprout is, so far as health goes, a true seedling, yet with a rate of height growth nearly as rapid as that of a sprout. Height Growth of Advance Growth So far the height growth of younger reproduction only has been con- sidered. Younger reproduction has been defined previously for the purposes of this bulletin as reproduction which originated on the area subsequent to the final cutting. Part of the area is occupied by advance growth com- 4i TREATMENT OF ADVANCE GROWTH posed of individuals which started during the twenty-year period just before the final cutting. The advance growth consequently may have a considerable advantage in height in competing with the younger repro- duction for position in the new stand. At the time of the final cutting the advance growth left on the area ranged from three to eighteen feet in height. Four years after cutting, the younger reproduction ranged in height from two to fourteen feet and the advance growth from five to twenty-eight feet. Consideration of the height growth made by the advance growth pre- vious to the final cutting is irrelevant. Its growth since the final cutting is of vital interest in determining the outcome of the competitive struggle between advance growth and younger reproduction. Over 10,000 indi- viduals of the advance growth were analyzed to determine their growth in height. Table 23, computed from the data secured, gives the periodic annual growth in height which the advance growth has made during the four years subsequent to the final cutting. Two facts of interest are brought out. One of them is, that the rate of height growth for a given species does not vary with the growth form. All four growth forms grow at practically the same rate. Compare with Table 22, rate of growth of younger reproduction, which shows great variation between growth forms. Sprouts in particular, as compared with seedlings of younger reproduction, grow more than twice as fast. It is evident that whatever advantage sprouts and seedling sprouts have over seedlings in ability to grow in height has already disappeared in the advance growth. This confirms the conclusion derived in another way (see page 41), that ultimately differences in height growth between the four growth forms will be overcome. The advance growth measured ranged from 3 to 19 years of age at the time of the final cutting. Rate of height growth follow- ing this cutting proved to be the same for advance growth of all ages within the 3 to 19 year range. The partial shading for a number of years before the final cutting doubtless has had an effect in evening off the difference in initial vigor due to origin and has placed all four growth forms on an even basis for future growth. The second fact of interest is that the differences between species have been leveled off. Such differences in the younger reproduction were smaller than the differences between the growth rates of the four growth forms. (See Table 22.) In the advance growth, differences due to species are less than the similar differences in the younger reproduction. White oak and hickory 42 I MM !' 23 SHOWING FOR ADA \\i ! GROWTH NIK RUT 01 HEIGHT crow 111 SINCE nil FINAL CI [TING, CLASSIFIED ACCORDING rO SP1 l . SPECIES, AND r, row ill FORM • m s Multiple Singl* fling ■■ /<■ 'til '.•tits Sprouts growth forms Mean annual hei Oaks Black Oak Chestnut Oak Red Oak S ai let O.ik White Oak Other Hardwoods Red Maple Hickory SIT! I •97 .98 .96 .84 .95 1.03 1 .04 1.04 .98 .96 •94 I.03 1.05 .98 • 99 .g 1 1. 01 1 .0 i .99 1.04 ■95 1.06 ■94 1.03 1. 00 I.02 • 99 1. 00 .98 SITE II Oaks Black Oak Chestnut Oak Red Oak Scarlet Oak White Oak Other Hardwoods Red Maple H ickory .80 •93 .89 • 78 .90 ■ 75 .96 .90 .87 •83 .89 .91 .81 •93 •97 .96 .85 .89 •94 .96 .90 .82 •95 •93 .87 .89 •95 .90 .82 .92 ■ 87 .87 SITE III Oaks Black Oak Chestnut Oak Red Oak Scarlet Oak White Oak Other Hardwoods Red Maple Hickory .63 •71 .64 .65 •73 .68 •75 • 65 .66 •57 .40 ■ 77 •63 .63 •63 • 67 .65 .69 • 50 •63 •70 .60 ■ 77 .63 •58 .64 .69 .62 .66 .76 .64 .66 Each average figure is based on from 15 to 500 dominant stems. Only in three instances is an average figure based on less than 50 stems. TREATMENT OF ADVANCE GROWTH appear to be growing faster both in actual amount and as compared with their associates. Red maple in comparison with its associates does not grow quite so well as in the younger reproduction. The actual growth rate maintained by the advance growth since the final cutting is approximately the same as that made by younger reproduction of seedling origin. On Sites I and II the advance growth is growing slightly faster than seedlings of the younger reproduction, while on Site III the reverse is the case. Evidently all growth forms of the advance growth when aided by the extra total height which they possessed four years ago can compete on at least equal terms with the younger reproduc- tion. The seedling sprouts and sprouts among the younger reproduction, growing from 50 to 1 50 per cent faster than the advance growth, may over- take and pass many of the advance growth stems. In some cases this has already taken place. All three classes of stems based on crown character (namely, well- formed, flat-topped, and abnormally-spreading crowns) were analyzed to determine their height growth. No difference in rate of height growth could be discovered among these three classes. Even the flat-topped trees have grown as well since the final cutting as trees of the other two classes. This should not be taken as implying necessarily for hardwood species an ability to recover quickly from the effects of heavy and prolonged shading. The overhead cover under which the advance growth on thinned areas develops is not dense. CONCLUSIONS AS TO THE PROBABLE COMPOSITION OF THE FUTURE STAND AND THE RELATIVE VALUE OF THE INDIVIDUALS WHICH IT WILL CONTAIN The amount, character, and distribution of the reproduction, and its height growth being known, conclusions can now be drawn concerning the ultimate composition of the stand which the reproduction now on the ground will produce. In addition, the future value of each element in the reproduction can be appraised. This can best be accomplished by con- sidering the situation on each site separately. Before this several things of general application on all sites, in reference to the relations between dif- ferent species, growth forms, and advance growth versus younger repro- duction, should be discussed. The Species in the Future Stand The future stand promises to be predominantly oak. Among the oaks, 44 1 RE \ l Ml\ I OF Al>\ AM ! GROW 1 11 red oak and chestnut oak will be prominent; the former particularly on Sites l and 11. because of its rapid growth, the lattei on Sites ill and [I, because of its great abundance and rapid growth. I 'he only undesirable oak is the scarlet oak, which, due to its susceptibility to heart ro1 and to the knottjness and low technical value oi the wood produced, must be ranked far below the other four oaks. Among the other hardwoods are some species, such as the tulip tree, white ash. and basswood, which grow fast and are oi high technical value. They form a very small percentage of the reproduction, i >n Sites 1 and 1 1 occasional individuals will keep a dominant position until maturity, and on the better soils may be more desirable than the oaks. The remaining tree species are all either of lesser technical value, or slower in height growth than the oaks. Study of height growth proves that the oaks find among the other hardwoods and woody shrubs only one .serious competitor for dominance in the future stand. This competitor is the red maple, which in ran- oi height growth compares favorably with the oiks, is found in abundance on certain sites, and is of shade-enduring habit. Silvii ulturally the red maple is better adapted to the region than most of the hardwood species. In the early reproductive stages its root system can adapt itself to any site. On better soils, a shallow root system adequate to meet the requirements of the trees is developed. On poorer soils a long tap root is developed, penetrating the soil to approximately the same depth as is reached by the oaks. Red maple is responsible for nearly all the suppression of oaks which occurs on the area. Relative Value of the Growth Forms The four growth forms range in order of desirability from seedlings down through single seedling sprouts and multiple seedling sprouts to sprouts, the least valuable form. Seedlings are the most desirable elements in a stand. Although characterized by slow growth during the early stages of development, they finally catch up with the more rapid sprout and seedling sprout growth and ultimately become dominant and codominant trees. From a physical standpoint they lead all other growth forms. The root system is uniformly distributed, radiates in all directions, and ensures a maximum absorption area and attachment to the soil. Single seedling sprouts are the next most desirable elements in the stand. They are practically equal to seedlings in their freedom from decay and general physical condition. Due to the one-sided development of the TREATMENT OF ADVANCE GROWTH root system characteristic of this form, there is some clanger from wind- throw. (See Figure 7.) On the basis of height growth they rank next to sprouts. Multiple seedling sprouts closely resemble seedling sprouts in their growth rate, but the increased number of stems directly increases the danger of decay. The original fusion with the old root system of the pre- vious generation may be complete, but the reduction in the number of stems which usually follows through competition again permits the entrance of decay. When only two stems develop from the old root system, this form may equal the single seedling sprout in vitality and become just as valu- able a component of the future stand. (See Figure 14.) Sprouts offer the greatest chance for the transmittal of decay from the parent stump and roots, and therefore are the least desirable. Sprouts will give a maximum production of material in the shortest period. The preva- lence of decay in this class of timber, however, renders it extremely unde- sirable from an economic standpoint. In a sprout stand, growth culminates in about forty years, and from then on deterioration progresses. As a general rule the seedlings and seedling sprouts (single and mul- tiple) can be considered desirable elements in the future stand. Relative Value of Advance Growth as Compared with Younger Reproduction The evidence at hand indicates that the great majority of dominant, free stems, both of the advance growth and of the younger reproduction, are of promising character. The small percentage not of promising char- acter owe their condition more to their source of origin (growth form) than to their time of origin (advance growth or reproduction arising subsequent to the final cutting). Height growth of younger reproduction of seedling sprout and sprout origin is much faster than the height growth made, since the final cutting, by the advance growth. (Compare Tables 22 and 23.) This will have the effect of at least partly overcoming the initial advantage in total height held by the advance growth, and will result ultimately in producing a uniform stand in which stems of advance growth cannot be distinguished by appearance alone from younger reproduction. Even the present larger classes of advance growth will be incorporated into the general crown level. Already many individuals of the younger reproduction are taller than many individuals of the advance growth. As time passes the fast growing seedling sprouts and sprouts in the younger reproduction will decrease 46 TR1 \ I MEN I 0] \l'\ Wtl CROW I'll their growth rate. Eventually (after the initial period) younger reproduc- tion cannot be distinguished from advance growth bj rate oJ height growth. It is remarkable hov. small a percentage oi the stems in the advance growth are of such poor character as to make them undesirable. Even the flat-topped trees, forming less than 6 per cent of the oaks, have the power of recovery and exhibit the same growth rate as the well-formed and abnormally-spreading crowns. Flat-topped oaks are usually not so crooked as to lessen their ultimate Lumber value. I 'he trees classed as abnormally- spreading will Improve in form as the stand closes. Most ot tins,- ab- normally-spreading trees ate of sprout origin. Red maple furnishes more examples of badly deformed flat-topped and abnormally-spreading b than do the other species. The conclusion reached is that whether a stein belongs to the advance growth or to the younger reproduction is immaterial in determining its value as a component in the future stand. Growth forms and species are of far higher significance. Conclusions on the Basis of Site Final conclusions can now be formulated for each of the three sites. Site I. The stand on Site I at the present time is fully stocked with noo oak and 3000 other hardwood stems of the better growth forms, free and well- formed, included among the 16,000 individuals on each acre. (See pages 25 w 30.) The area now occupied by the free, well-formed seedling and seedling sprout oaks of all live species is only 20 per cent of the total. (See Table 11.) This may be expected to increase to 50 per cent of the total area by the time the stand is fifty years of age. The remaining area will be occupied by well-formed, free seedlings and seedling sprouts of other hardwoods, 1 5 per cent, and by sprouts and poorly formed stems of other growth forms, 35 per cent. Woody shrubs will disappear entirely as part of the main stand. Most of the other hardwood stems, due to their slower growth rate, become over- topped by the oaks and lose a large share of the area held in the reproduc- tion stage. Other hardwoods which appear in a dominant position in the future stand will be principally of good species, such as tulip tree, ash, basswood. and black birch. Many of the sprouts, both oak and other species, cannot be classed as 47 TREATMENT OF ADVANCE GROWTH wholly undesirable elements in the future stand. While rot will enter earlier in the sprouts than in stems of other growth forms, yet, when grown on a sixty to eighty-year rotation, many sprouts will be sound. As the length of rotation increases, rot in the sprouts increases and the relative value of this growth form becomes less and less. Table 24 gives for each of the three sites the percentages of the area occupied by different classes of stems in the future stand. The figures in this table are estimated from general observation checked by measurements taken in a few individual stands. TABLE 24 SHOWING PERCENTAGE OF AREA ON EACH SITE OCCUPIED BY WELL-FORMED, FREE SEEDLINGS, AND SEEDLING SPROUTS OF OAK, AND BY OTHER CLASSES OF STEMS IN STANDS MORE THAN FIFTY YEARS OF AGE Site I Site II Site III Percentage of total area Oaks, well-formed, free seedlings and seedling sprouts 50 55 55 Other Hardwoods, well-formed, free seedlings and seedling sprouts 15 10 5 Sprouts, all species, and poorly formed seedlings and seedling sprouts 35 35 40 Woody Shrubs 0 0 0 Total 100 100 100 Site II. The reproduction on Site II forms a fully stocked stand with oaks making up 46 per cent of the number of stems. (See Table 5.) Out of 12,000 stems on the average acre, 1100 are free, well-formed seedling or seedling sprout oaks and 1000 are other hardwoods of similar character. (See pages 31 to 34.) In the reproduction stage, this class of oaks occupied 35 per cent of the area, and other hardwoods 25 per cent. (See Table 11.) The figures in Table 24 indicate what may be expected in the future stand. It is seen that 55 per cent of the area will be taken by the free, well-formed seedling and seedling sprout oaks ; 1 0 per cent by other hard- 48 TREATMEN r OF \i>\ Wir GR< »\\ I n woods; and the remaining 35 per cent by sprouts and poorl) formed stems, On both Sites l and 11 the oaks in the future stand will be .1 varying mixture of all five species, with chestnut oak increasing on Site M. Site in. Fifty-nine per cent of the reproduction on Site 1 1 1 is composed of oak. Out of 5000 stems per acre, 1 [oo are free, well-formed seedling ami seed- ling sprout oaks, while only _;oi> are other hardwoods of similar character. (See pages 34 to 37.) It is interesting to note that in the reproduction stage the number per acre oi free, well-formed seedling and seedling sprout oaks is the same on all three sites, while the number of other hardwoods of similar char- acter decreases from ^000 to 500 p,r acre in passing from Site 1 to Site 111 The 1100 oak stems occupy 35 per cent of the area in the reproduction . and the 500 other hardwood stems 20 per cent. Only 10 per cent is covered by woody shrubs. Sprouts and poorly formed seedlings and seed- ling sprouts have possession of 35 per cent of the area. In the future stand the woody shrubs disappear from the main canopy; free, well-formed seedling and seedling sprout oaks increase to 55 per cent of the area; other hardwoods of similar character drop to 5 per cent; and sprouts and poorly formed seedlings and seedling sprouts spread out to cover 40 per cent of the area. A large share of the oak area in the future stand on Site III will be occupied by chestnut oak. The other hardwoods in a dominant position will be of species less desirable than the oaks on this poor site. All Sites. Summed up for all sites, the future stand will be fully stocked, even-aged, with at least one-half the area occupied by oak of the better growth forms, principally seedling sprouts. The remaining one-half of the area, although in possession of other species than oak, or of sprouts and poorly formed individuals of all species, will contain many individuals of equal value with the oak of better growth forms. The distribution of the different species and growth forms in the future stand should be approximately uniform over the area, with the exception of chestnut oak on the poorer sites. A general mixture of the oaks, with a small percentage of such hardwoods as hickory, hard maple, red maple, ash, black birch, tulip tree, and basswood, will be characteristic. There is reason to believe that red maple, which in the reproduction stage is a strong com- 49 TREATMENT OF ADVANCE GROWTH petitor of the oaks, will show a decided decrease in growth rate during middle age and occupy in the mature stand an intermediate or codominant position in the crown canopy. Stems both of advance growth and of younger reproduction will be inter- mixed in the mature stand and will only with difficulty be distinguished. The differences in initial height existing, just subsequent to the final cutting, between advance growth of various ages and the younger repro- duction, instead of being disadvantageous may be of benefit, in allowing earlier and more marked differentiation into crown classes, and in pre- venting in the sapling stage too even and hence too severe a competition between individuals. TREATMENT ADVISED TO IMPROVE THE FUTURE STAND The treatment advised for the advance growth during the early period following the final cutting may appear largely negative. Investigation of the height growth and character of the advance growth has shown that the great majority of the stems are of promising character. It would be a mistake, expensive financially and silviculturally, to cut back to the ground or otherwise remove the advance growth as a whole. Instead, the advance growth should be protected, so far as is practicable, during the logging operations which remove the old stand. There are certain individual stems whose removal in the reproduction stage would result in improving the composition and quality of the future stand. It is evident from the preceding pages that these undesirable stems must belong to one of three classes : Flat-topped individuals so deformed as to have no future possibilities. Dominant stems of inferior species overtopping oak or other desirable species. Dominant individuals of the sprout growth form. Individuals in the last two of these classes may be either younger repro- duction or advance growth. The operation here needed falls within the scope of a cleaning,9 since it removes dominant trees in a young stand to free more desirable stems of the same age as those cut. The making of a cleaning should be deferred until three to five years after the final cutting. This enables the stems which will be freed to reach such a height that when freed they thereafter can remain in a dominant position. In some instances it may be necessary to make a second cleaning; 9 Hawley, R. C. : Practice of Silviculture, 1921, p. 144. 50 1 Rl A I Ml \ 1 OF Al>\ WiT CROW 111 this will require less cutting than the first Each cleaning involves an expense amounting to the cost of from one-fourth to one day's work per acre. The question is an open one, whether or not in mixed hardwood stands such cultural operations as cleanings are too intensive for present-day prac- tice. An independent answer must be sought in each individual case. in general an Investment for cleanings appears justified in many instances. Insufficient knowledge as to the future yields to be expected from hard- wood stands prevents for the present a more definite statement \\< accomplish nearly the same result in the end there is another method of treating young hardwood stands, which does not involve an investment of money in a cleaning operation. The stand ^an be allowed to grow on untouched until of cordwood size. As soon as a partial cutting for cord- wood can be made profitably — that is. when the material removed will at least pay for the expense of the operation— the stand should receive an improvement cutting.10 At this time the stand usually will be between twenty-five and thirty-five years of age. The improvement cutting is in reality a delayed cleaning. Not all of the undesirable stems can be removed at the first operation. The principle may have to be followed in several successive cuttings made at intervals of five to twelve years before the area is brought entirely under control of the more valuable stems. As stated on page 48, many oak sprouts reach ages of sixty to eighty years without being seriously injured by butt rot. Hence on rotations of this length these sound sprouts are not undesirable elements in the stand. Recognition of this fact should influence the marking in the first improve- ment cuttings. The more dangerous elements — namely, dominant trees of inferior species and badly deformed individuals of any species — should be taken out before the sprouts as such are discriminated against. Table 24 indicates that from 50 to 55 per cent of the area in mature stands will be occupied by well-formed seedling or seedling sprout oaks. By means of two to three improvement cuttings, it should be possible to pro- duce stands of practically pure seedling or seedling sprout oak. This result is predicated upon the possibility of selling cordwood of small size. Where such utilization is practicable, the method of improve- ment cuttings is preferable to a cleaning. In many cases cordwood of small size cannot be profitably handled and improvement cuttings between the twenty-fifth and fiftieth years are impracticable. Under such conditions, 10 Hawley, R. C. : Practice of Silviculture, 1921, p. 192. 51 TREATMENT OF ADVANCE GROWTH if a stand of pure seedling and seedling sprout oak is wanted, a cleaning should be made three to five years after the final cutting. In conclusion, this study finds that advance growth arising as a result of thinnings and shelterwood cuttings requires no special treatment dif- ferent from that needed for the purpose of improving the composition and quality of the average upland mixed hardwood stand. This treatment resolves into the making of either cleanings or improvement cuttings. The latter, since they require no direct cash outlay, are preferable wherever small cordwood is salable. 52 II. 1. 1 SI R \ I IONS fig. i. General view of i representative portion of the area intensively studied. m i t>> 22 id in height from _• to 28 feet. Fig. 2. Part of the same area shown in Fig. 1. The taller trees are advance growth. Younger reproduction and advance growth are intermixed in the medium and lower height classes. : Fig. 3. Red oak seedling showing clusters of dormant buds near the root collar. 54 Fig. 4. Red oak single seedling sprout showing stub of previous generation and abrupt curve in taproot. :: Fig. 5. Red oak single seedling sprout showing variation in the point of origin of new stem. Compare with Fig. 4, where new stem started on the outer side of old stub. Fig. 6. Red oak single seedling sprout 4 years old and 0.5 feet in height. This tree grew 4.5 feet in height during the first year. 57 Fig. 7. Mature oak single seedling sprout showing the characteristic swollen base and curve at one side, and the straight sweep of the stem on the opposite side of the trunk. 58 Fig. S. Red oak seedling showing the first year's growth and the slight curve in the taproot, as compared to the abrupt cum characteristic of seed- ling sprouts. (See Figs. 4 and 11.) Lateral roots are seen developing close to the base of the stem. In seedling sprouts these develop lower down on the tap- root. (See Figs. 4 and 10.) Fig. 9. Multiple seedling sprout showing the characteristic develop- ment of more than one stem. The stub of the original seedling which had been cut still remains. Several sprouts developed but competition has reduced the number to two. Note large lateral roots developing from point well below the root collar. (Compare with Fig. 8.) 60 Pig. 10. Usual form of multiple seedling sprout with one stem slightly larger in diameter than the other. 61 Fig. ii. Red oak multiple seedling sprout with two generations of sprouts. The larger stems are each 4 years of age, the dead stems showed 7 growth rings, and the root 14 rings. The tree lived under the previous stand for 3 years as a seedling and 7 years as a multiple seedling sprout, and then developed the present generation of stems. The root is not decayed but was damaged when it was removed from the soil. 62 Fig. 12. White oak multiple seedling sprout 4 years old and 6 feet high. 63 Fig. 13. Red oak multiple seedling sprout 4 years old. The large stem was 8.2 feet in height, the other 7 feet. A difference in the height of the stems is characteristic of this growth form. 64 .I. Mature multiple seedling sprout. Fig. 15. Chestnut oak seedling 4 years of age. The young sprout is 3 weeks old. This is an excellent illustration of an early stage in the trans- formation of a seedling into a seedling sprout. The stem of the seedling ■was damaged by rodents and the young sprout has developed as a reaction to this injury. 66 Fig. i ft. Typical example of advance growth sho%ving the •well-formed crown and straight stem characteristic of this class of reproduction. This is a single seedling sprout 22 years old. 24 feet in height, and 5.2 inches I). B. II . 67 Fig. 17. White oak multiple seedling sprout of ad- vance growth. Note healthy appearance of crown and stems. 68