Although the conventional methods of predicting growth of trees and stands by the measurements of variables on the ground yield a considerable degree of accuracy, they take a long time and are expensive. Therefore, prediction of growth of trees and stands by the use of aerial photographs as developed herein may be preferable in some situations. A survey was made of ten series of aerial photographs taken at various times during the year with the use of several kinds of photography. One series was omitted because of too much exaggeration of relief. Of the nine series, three were regarded as inadequate for growth studies due to poor photography. Repeated measurements were made for 135 sample trees on different series of photographs in terms of total height and crown width. The tree images were classified as good, medium and poor according to the visibility of both top and the base of tree, and the accuracy of height measurements was defined in terms of standard error of the mean difference from photo-measurements and the ground data. In addition to the conventional method of taking an average of four parallax readings or two identical readings, the writer set up a checking method by which a high degree of accuracy was secured. The standard error of the mean difference for 95 heights of good image trees was ± 0.23 feet. When the good image trees were classified as conifers or hardwoods, the standard errors of the mean differ- ences were ± 0.30 feet and ± 0.41 feet respectively. Generally the measurements of height for conifers appeared to be more accurate than those for hardwood. There was no consistent result indicating which species gives better measurements. For height growth estimation, Height/Age curves were used as a supplement to ground data, and a method of pooling errors was applied. The use of this method for determining the accuracy of growth prediction was assumed to be applicable, and height estimates based on direct measurements on different series of photographs yielded a considerable degree of accuracy, if good quality photographs were available. The accuracy of crown width measurements was fairly high. The smallest standard error of the mean difference was ± 0.21 feet for 53 Douglas fir and the largest standard error of the mean difference was ± 0.58 feet for 12 alders. For growth estimates of crown width, the indirect approach of using Crown width/dbh ratios was used as a substitute for ground control. It was concluded that the prediction of growth of crown width can be made from a series of aerial photographs. The application of theoretical values as criteria in determining the acceptability of growth estimates of crown width might be practicable because variation will be reduced by the joint computation of two pairs of observations. However, when Crown width/dbh ratios are used as control, there tends to be a great deal of error, partly because of the use of ratios. Accuracy of growth studies on three different groups of plots varies with the composition of stand. The group of young natural regeneration plots showed a relatively high degree of accuracy. It was concluded that where the stand is comparatively open, growth estimates on the photographs would give a useful degree of accuracy. / Forestry, Faculty of / Graduate

A study was made of single wood samples from 35 species (27 genera and 16 families) of important Taiwan timbers. Results have been compared with information published by Kanehira in 1921 (30) and others (31, 44). The anatomy of these woods is described in detail. A key based on microscopic features is included for identification. Descriptions follow standard terms of the International Association of Wood Anatomists Two of the coniferous species, Pinus armandi Franch. and Chamaecyparis formosensis Matsum., and nine hardwood species Carpinus kawakamii Hay., Quercus gilva B1., Quercus longinux Hay., Cinnamomum camphora Nees., Cinnamomum randaiensis Hay., Lagerstroemia subcostata Koehne., Gordonia axillaris (Don.) Szysz., Trochodendron aralioides S. et Z., and Trema orientalis B1. had features similar to those reported (30, 31, 44). Seven hardwood species, Alnus formosana (Burkill.) Makino., Quercus stenophylloides Hay., Engelhardtia formosana Hay., Beilschmiedia erythrophloia Hay., Cinnamomum micranthum Hay., Zelkova formosana Hay., and Tectona grandis Linn, f. showed different anatomical features from those recorded by Kanehira (30) and Kribs (31). No previous description of wood anatomy has been found for seventeen species including Tsuga chinensis (French.) Pritz., Cunninghamia konishii Hay., Libocedrus formosana Hay., Chamaecyparis taiwanensis Masam. et Suzuk., Scheffera octophylla (Lour.) Harms., Castanopsis longicaudata Hay., Castanopsis stipitata Hay., Lithocarpus amygdalifolia Hay., Actinodaphne nantoensis Hay., Machilus arisanensis Hay., Machilus pseudolongifolia Hay., Machilus zuihoensis Hay., Cassia siamia Lam., Michelia formosana Mas., lllicium leucanthum Hay., Schima superba Gard. et Champ, and Ternstroemia gymnanthera Spr. All species treated in this study are described in more detail than occurs in past records. Mass grouping of longitudinal parenchyma appears as a normal feature of Cunninghamia konishii Hay. This type of parenchyma distribution could be a taxonomic feature of Cunninghamia not previously described in the literature. / Forestry, Faculty of / Graduate

In Kenya, as in British Columbia, a high percentage of the forest land is owned by the Crown. Since Government controls most of the raw material for the forest industry, its timber disposal policies will have a considerable influence on the pattern of industrial development. The most suitable policy will be that which allows the maximum degree of industrial efficiency to be achieved and at the same time, adequately protects the public interest in the forest resource. The main methods of timber disposal open to the Kenya Government are: (i) To dispose of all Crown timber by public auction. (ii) To grant leases of Crown timber to private enterprise concerns, Government retaining the responsibility for forest management. (iii) To grant leases to private enterprise concerns and, in addition, to delegate to these same concerns the responsibility for forest management. Such a lease would be equivalent to British Columbia's Tree Farm Licence. (iv) To dispose of Crown timber by outright alienation. (v) To establish State manufacturing plants. It is not essential that the Government commit itself to any particular one of the above alternatives in practice, a combination of two or more may be desirable. This thesis is primarily concerned with the Tree Farm Licence method of timber disposal. The main objectives are: to study the progress of the Tree Farm Licence, to assess its advantages and disadvantages and to discuss its applicability in Kenya. The main conclusions drawn are that the Tree Farm Licence has brought several important benefits to British Columbia and in particular, has encouraged the establishment of the large integrated forest industries which play an important part in supporting the Provincial economy. The introduction of a similar licence into Kenya would be desirable, but for political reasons probably impracticable at present. / Forestry, Faculty of / Graduate

Classification of site of forest land is possible on aerial photographs. This classification can be based on topographic features, physiographic features, forest cover types, or on their combinations. Aerial photographs of the University Research Forest were typed using the following topographic features: exposure, percentage of slope, shape in profile, and shape in contour. Data on topographic and physiographic features were collected on 238 sample plots within topographic types in 30-year-old stands, on 83 permanent sample plots in 70-year-old stands, and on 26 sample plots in old-growth stands. Both graphical and mathematical analyses were carried out to determine relationships among site index and thirteen site factors. Simple correlation coefficients for site index of each of 320 plots were highly significant for each of local and general position on slope, per cent of slope, elevation, soil depth, moisture regime, permeability, soil texture, and thickness of A₂ later. Shape in profile was significantly associated with site index. Aspect, shape in contour, and thickness of the humus layer were not significantly associated with site index. The best of the single factors was moisture regime, but use of this by itself could only account for 20 per cent of the variation inplot site indices. Linear multiple-regression equations were computed to estimate site index from various combinations of topographic and physiographic variables. These equations were not used further in this study for determination of site index because of their relatively high standard error of estimate; however, several potentially useful equations were recognized. The best multiple-regression equation was highly significant statistically but accounted for only 31 per cent of the variation in plot site index. It included aspect, local and general position on slope, per cent of slope, shape in profile, elevation, and moisture regime. A procedure was developed to estimate site indices directly from aerial photographs by stereoscopic examination. Photo-estimation of site index was much more accurate than the computed equations based on all data collected in the field. Standard errors of estimate were reduced from 23 feet to 16 feet by direct estimation of site index. Regression equations were developed for conversion of site index of Douglas fir, western hemlock, and western red cedar from one species to another and to the average of all three species. Site maps were prepared for the 30-year-old stands which had not been mapped in the 1950 inventory of the University Research Forest. Preliminary site and forest cover types were recognized and general stand and stock tables were developed to describe these 30-year-old stands. / Forestry, Faculty of / Graduate

Various investigators of logging operation efficiency have stated that the harvesting of small trees is inevitably associated with higher operating costs. A comprehensive survey of literature has been presented to substantiate this fact. The cited information was supplemented, for the purpose of this thesis, by a time study conducted at the University Research Forest, near Haney, B. C, in June, 1961. During this study felling, bucking, yarding and loading of timber was studied at two different operations in that Forest. These studies supplied basic data for the computation of the size of the zero marginal tree. It was found that, under existing conditions, the indicated sizes were 12 and 14 in. d.b.h. for Douglas fir and hemlock trees, respectively. Further it was shown that the milling operation constituted the largest cost component, especially penalizing the small dimensions. A new schedule, with certain proposed improvements in operating efficiency, was established. Under this schedule the milling operation was omitted, and the logs were assumed to be the final, marketable product. The solution of this computation revealed that, under the assumed conditions, the zero marginal limit in terms of d.b.h. for Douglas fir and hemlock was lowered to 7 and 8 in., respectively, provided the logs from such small trees could be sold at the same price as # 3 sawlogs. The shape of the net return function suggests, however, that only around and above 15 in. d.b.h. could the operation be regarded as safely paying its way, under current market conditions and restrictions as to minimum log size and length. The technique of linear programming (LP) has been successfully employed in other sectors of manufacturing and transportation. It is demonstrated in this thesis that the LP technique may be applied to certain forest harvesting situations. Progressing through three problem situations of increasing complexity, it is shown how an optimum strategy of action may be established in terms of the economically marginal tree size. The difficulty of obtaining precise time and cost values in sufficient quantity was encountered throughout this work. Consequently, the main purpose of these computations is to illustrate the underlying principles of the application of LP, and to demonstrate its applicability to certain aspects of forest harvesting problems. This area offers wide scope for future investigation and for improvement of techniques. / Forestry, Faculty of / Graduate

These soil studies were carried out on eight permanent plots at the University Research Forest, Haney, B.C. These plots ranged in Douglas fir site quality values 80 to 180 feet at 100 years. The soil of each plot was examined by means of soil pits and soil samples were taken for laboratory analysis. For each plot, topography, vegetation, general moisture condition, degree of stoniness, nature of soil and for each profile depth of horizons, soil color, texture, structure, consistence the amount and position of organic matter, drainage, physiologic depth, depth to mottling and special features of the profile such as hardpan, orstein, shot material, root mats were determined. In the laboratory, per cent soil skeleton, texture specific gravity of soils, bulk density, total-pore space, macro-pore space, micro-pore space, hydraulic conductivity and available water between 0.1 and 15.0 atmosphere (corrected for soil skeleton and/or soil stoniness), soil acidity, total cation exchange capacity, exchangeable calcium and potassium, and organic matter content were determined. Statistical analyses were conducted to determine the significancy of the values obtained in laboratory analysis. Regression equations were determined for evaluating site index from morphological soil characteristics such as horizon thickness, depth to mottling. The soils of the area were mainly derived from glacial till. Till is a coarse texture (coarse sandy loam to loamy sand) containing gravels, stones, and boulders. It was generally hard and impervious to water movement. The profiles generally have shown Aₒₒ, Aₒ, A₂, B₁₁, B₁₂, B₃ and C horizons, ^he development of eluvial and illuvial horizons (especially clay accumulation) appeared somewhat weak. Profiles have shown coarse texture similar to that of glacial till. The depth of profiles varied between 5 and 33 inches, the average range being from 20 to 30 inches. Two main soil groups were observed among the eight plots. Plots 2, 3 and 4 were minimal podzol (Order: Podzols), plot 1 was concretionary brown (Order: Brunosolic), and plots 5, 6, 7 and 8 are classified as intergrade between concretionary brown and minimal podzol. Generally the coarse skeleton comprises more than 50 per cent of the soil. All the soils were very low in clay content. Hydraulic conductivity was high. Micro-pore space showed higher per cent layers than macro-pore space. The available water was low in general due to texture. The preponderance of stones in the soil had an adverse effect on the water-holding capacity of the soil. Consequently, stoniness had to be taken into consideration in determining the actual volume of available water. All the soils were acid in reaction. The organic matter was high in upper horizons and decreased with depth. Total cation-exchange capacity exchangeable, calcium and potassium and calcium base saturation were low. Correlation studies between soil properties and site quality indicated that the physical soil properties were more important than chemical characteristics as an indication of soil quality. Texture, bulk density, porosities (macro-, micro and total), hydraulic conductivity did not show any correlation with site quality but were significant at the 5 per cent level between the plots (except micro-pore space). Available water was positively correlated with site quality when it was corrected for stoniness and coarse skeleton. Chemical properties were not significant between the plots and did not show any correlation to site quality. Morphological features such as thickness of B₁₁ horizon and depth to mottling were highly correlated to site quality and gave the smallest standard error of the estimate (± 21.3 feet). The study indicates that the volume of available water in the soil was most important for the growth of Douglas fir and that the site index of an area could be determined from a study of those morphological features of the soil which affects its water-holding capacity, as well as other morphological features such as depth to mottling. / Forestry, Faculty of / Graduate

The photo-interpreter has a difficult task when he is asked to identify the images of tree species recorded on aerial photographs. When a tree is examined on an aerial photo for such a purpose, the difficulty becomes more and more evident as it is realized that the different species can not always he identified by eyesight, even on large-scale photographs, but must be viewed stereoscopically, and the variations in appearance within the same species, even growing under the same conditions, are very great. In comparison with identification on the ground, the interpreter must take an entirely new approach in the determination of various species from aerial photographs. This approach involves training the eyes to recognize plants appearing with various hues and grey tones on black and white photographs, at much smaller scale than usual in ground studies, in most cases from above or half-oblique view of the tree, which is strange to the inexperienced interpreter. Most of the trees appear on aerial photographs in vertical or oblique views, when the branching habit and the crown shape of a tree are easily visible. For this purpose it is desirable to know the characteristic branching habit and typical crown shapes of trees in order to use these factors in species identification. This leads up to the problem that will be presented in this thesis. Factors which influence the ground characteristics of three major tree species in British Columbia are examined and analyzed. Various crown forms, with which Douglas fir, western hemlock and western red cedar occur in the vicinity of Haney and Vancouver, are described. The basic pictorial elements, with which these species appear and enable us to recognize them on aerial photographs, are analyzed. Influence of different films and filters on the appearance of species on air photos are also discussed. The thesis presents an analysis of identifications of species made by several interpreters. Requirements for photo-interpretation are also discussed. Finally, a dichotomous key is presented, which is constructed for Douglas fir, western hemlock and western red cedar, taking into account their appearance at various ages and locations. / Forestry, Faculty of / Graduate

Literature dealing with the development of height-age curves was reviewed. The advantages of “natural" height-age curves, which have variable rather than the "conventional" fixed form for all sites, were examined. Data collected from stem analyses of 53 dominant and 44 codominant Douglas-fir trees felled on five permanent sample plots in the University Research Forest, Haney, were analysed in order to develop natural height-age curves. A growth curve was constructed for each tree. Master curves were prepared for each plot and for each crown class. [The site index of each plot and for each crown class.] The site index of each plot was determined at the standard age of 100 years. Straight line regression equations of height over site index by age classes were developed. The feasibility of harmonization of the regression coefficients was examined. Sheaves of natural site-index curves were derived. The analysis was repeated three times with various modifications of the basic data. Analysis II was selected as the basis against which 11 sets of "site-index" curves derived by 10 different authors from data collected in various environments by various methods were compared. A comparison of three different height-age natural curves with the derived curves was made for very young trees. Also, the five-year growth in height on five permanent sample plots was compared with height-age curves derived from data collected on the same plots. The advantages of natural "site-index" curves as compared with standard height-age curves were discussed. / Forestry, Faculty of / Graduate

This study examined whether the current generation of consumer-grade digital mobile computing technology, so called smartphone technology, is usable to perform and improve field data collection in the context of sustainable forest management. An electronic data acquisition system, based on a handheld smartphone device and desktop geographic information system (GIS), was developed. A proprietary timber cruise application and commercial mapping software were used with the smartphone/desktop GIS to record and process forest stand and geospatial data. Usability testing was carried out to measure workflow efficiency and system performance of the smartphone GIS compared to traditional paper-based methods. The smartphone GIS successfully met performance objectives and significantly increased workflow efficiencies by improving data transfer and processing times over conventional paper methods; however, use of the mobile device resulted in greater data entry errors, increased data collection times, and led to more equipment malfunctions than use of paper recording methods together with a GPS and digital camera. Overall, the prototype electronic data acquisition system was not reliable as a stand-alone solution solely responsible for collecting cruise data, but was found to be well suited for ad-hoc mapping of forest features.

Tree and tree component weights of 63 forest-grown lodgepole pine trees were investigated. Data were collected from one tenth-acre plot located in south western Alberta. Both graphical and multiple regression techniques were used. Of the independent variables tested, tree basal area was most closely related to the component weights, with the exceptions of bole bark weight and total stem dry weight. The fresh and dry weights of bole bark were most closely associated with tree height, and total stem dry weight was most closely associated with dbh. Very reliable estimates of tree and tree component weights were obtained using regression techniques and the independent variables previously mentioned. The proportions of the component weights of the total tree weights were determined. The proportions were highly variable and widely dispersed about the mean. The tree characteristic most closely associated with the various proportions varied for the component being analysed. The proportion of the total tree weight contained in the stem, slash, bark and bole wood decreased with increasing tree size. The proportion represented by the needles, branches, merchantable stem, and crown increased with tree size. The crown and needle characteristics of lodgepole pine were investigated. Tree size, whether measured as stem weight in pounds or cubic foot stem volume (ob), was most closely correlated with dry needle weight (in pounds). The number of needles per cubic foot of stem volume increased with increasing tree size. The needle characteristics of lodgepole pine are highly variable. Needle length was significantly related to needle width. Needle length was not significantly related to any tree characteristics. The need to develop reliable sampling methods for biomass and fire control studies was discussed. Double sampling with regression appeared to offer accurate estimates with a minimum of weight measurement. The number of trees required to obtain a sample mean within plus or minus 10 per cent of the population mean at the 95 per cent confidence level is too large to be practical for most biomass and fire control studies. A higher standard error of estimate is probably more desirable, thus allowing a greater number of conditions to be sampled in order to increase the representativeness of the study. The mutual relationship between tree weight and tree volume was investigated. Tree volume was highly correlated with tree weight. Reliable estimates of tree weight were obtained from tree volume. Variation in moisture content and specific gravity, within and between trees was analyzed. These variables were surprisingly uniform and appear to pose only minor problems in weight scaling, for lodgepole pine. / Forestry, Faculty of / Graduate