Estimation of soundwood volume and value is particularly important in British Columbia because nearly half of the forests are overmature or decadent. The objective of this thesis was to develop analytical techniques to define distribution of gross and net volumes within individual standing trees in order that appropriate reductions for decay could be made for estimates of volumes of logs of specified sizes and grades. Relationships of heartrot to stand and tree characteristics and to external abnormalities were analysed for 369 western hemlock (Tsuga heterophylla (Rafn.) Sarg.) trees from the Yale Public Sustained Yield Unit in British Columbia. Comprehensive sorting, correlation and regression analyses were carried out on an I. B. M. 7044 electronic computer. One multiple regression equation provided estimates of total decay volume within individual trees from DBH, total height and external indicators of decay. It had a standard error of estimated decay volume of 18.7 cubic feet (19.5 per cent). A second equation estimated decay volume within individual logs in standing trees from the above variables and from section height. It had standard errors of estimate ranging from 13.7 cubic feet (31.6 per cent) in butt logs to 0.1 cubic feet (2.9 per cent) in top logs. The best taper function which could be derived to estimate upper stem diameters inside bark had a standard error of estimate of 1.29 inches using measures of DBH and total height. Combination of the log and tree decay estimating functions and the taper function facilitated complete description of the soundwood volumes in the sample of 369 trees. A graphical analysis was developed whereby percentages of trees in a stand with more or less than specified decay volumes could be estimated. Preliminary chemical studies of western hemlock wood infected with Echinodontium tinetorium E. and E. indicated that cellulose yields were slightly less than those from soundwood. Such partly decayed wood might be used for the manufacture of pulp without serious reductions in yield on a volume or weight basis. Further research is needed to substantiate the possible cyclic nature of decay losses and to determine the influence of bark thickness and natural pruning on the distribution of decay within individual trees. Application of the analytical techniques developed for western hemlock to other species should result in more precise estimates of soundwood volumes and values, thereby contributing to improved management planning and utilization. / Forestry, Faculty of / Graduate

Sustained yield forest management has been widely accepted as a major objective of forestry. It implies continuous production of forest crops with the aim of achieving, at the earliest practicable time, an approximate balance between net growth and harvest, either by annual or somewhat longer periods. The concept, introduced to North America by European foresters at the end of the 19th century, has become an important component of public policy for forestry and conservation. History of sustained yield forest management, its role in conservation philosophy, and its economic advantages and disadvantages, as well as alternatives, are discussed. Evolution of sustained yield management and its application in British Columbia are described. Many advantages have been claimed for sustained yield forest management as an alternative to unregulated liquidation of resources. Yet preservation of forests for the benefit of future generations, amelioration of uncertainty in forestry enterprises, protection of social values, stabilisation of communities, and provision of regular incomes, cannot, themselves, justify unconditional acceptance of sustained yield. Sustained yield forest management emphasizes stability and continuity of production but neglects economic values of the resource. It may even retard economic growth and development. By using physical rather than economic criteria to set goals for forest management, sustained yeild often causes the net present worth of the forest resource to fall short of its maximum potential value. Although sustained yield policy aims at stability, the inability of entrepreneurs to respond to cyclical changes in economic activity may actually lead to instability in stumpage prices and forest revenues. The rational forest owner should only practise sustained yield forest management if it will achieve his objectives in the most efficient manner. Forest owners should always consider alternatives to sustained yield. Benefits must be analysed in relation to costs. Forest management planning also can be improved by linear programming and decision theory techniques as illustrated herein. It is suggested that in British Columbia sustained yield forest management has become so firmly established that alternative policies are seldom considered. Rigid application of sustained yield principles forms an effective barrier to maximization of the social value of the Provincial forest resource. Opportunities for expansion of lumber and plywood industries are being curtailed, and inadequate attention has been given to planning of the transition from old growth to second growth stands of Douglas fir. Despite its emphasis on "perpetual yields of wood of commercially usable quality from regional areas in yearly or periodic quantities of equal or increasing volume", forest management in British Columbia has neglected urgent needs for improved reforestation. After a thorough examination of its implications for British Columbia, it is concluded that sustained yield must be rejected as a universal goal of forest management. Sustained yield forest management should always be compared to other alternatives and be fully justified on economic and social grounds before it is accepted. / Forestry, Faculty of / Graduate

The study was concerned with lodgepole pine, Pinus contorta Douglas and Engelmann spruce, Picea engelmannii Parry, particularly in the southern interior of British Columbia. Classifications of the forests of the Province as well as distribution, silvics, effects of fire upon succession, forest associations, and productivity classes of the two species were described. Sample plots were located in the Interior Douglas-fir and Engelmann Spruce - Alpine Fir Biogeoclimatic Zones. Hohenadl's form factor was used to compute volume growth by individual decades from stem analyses. On 124 plots, 137 trees were collected for stem analyses, 108 saplings were used for height - age studies, 100 point samples were made for determining basal area and stand volume and several hundred heights as well as diameters and borings at breast height, were taken. Thirty-four stand variables were subjected to multiple correlation analyses, particularly in regard to forest associations and growth of height, diameter at breast height and volume of the two species. Simple regressions were used to estimate height growth of several species on similar sites, and to compare several methods of volume calculation. Trees of the same diameter at breast height grown in different competitive positions (open, moderate to dense, and suppressed), contained different volumes. The largest volume of individual trees was found with trees grown in moderate to dense competitive position. Individual young lodgepole pines had a faster increment of height, diameter at breast height, and volume, than Engelmann spruces. This trend remained the same in yield tables based on individual tree studies and constructed for stands of good (average site index 100 ft. at 100 years), medium (average site index 70 ft. at 100 years), and poor (average site index 50 ft. at 100 years) productivity classes. The mean annual increment of volume of stands culminated earlier in lodgepole pine than in Engelmann spruce. The periods required were (in brackets are shown attained average diameters at breast height, total heights and volumes per acre). In the good productivity class in lodgepole pine 40 years (8.3 in., 58 ft., 6,700 cu.ft.) and in Engelmann spruce 75 years (10.0 in., 80 ft., 6,000 cu.ft.); in the medium productivity class in lodgepole pine 60 years (6.5 in., 50 ft., 4,600 cu.ft.) and in Engelmann spruce 130 years (9.0 in., 84 ft., 5,100 cu.ft.); in the poor productivity class in lodgepole pine 85 years (5.3 in., 45 ft., 3,100 cu.ft.) and in Engelmann spruce 150 years (6.3 in., 66 ft., 3,400 cu.ft.). Yield table volumes per acre in lodgepole pine were larger than those of Engelmann spruce, in the good productivity class, to the age of 120 years, in the medium productivity class to 150 years, and in the poor productivity class for an undetermined period. Present and suggested future trends of utilization and management of stands of the two species were reviewed. Generally, forest management in British Columbia shows a trend toward more intensive forest utilization, due to the increasing demand for wood. Smaller diameter trees and "smallwood" stands will be more and more frequently utilized. Utilization of whole trees, highly mechanized "harvesting" and transportation as well as intensified management of forest stands will compensate for increasing costs due to utilization of smaller diameters. Under intensive management, lodgepole pine deserves special consideration. It is as well-suited for artificial establishment of stands by planting as Engelmann spruce, but should cost less. Its value for the woodworking industry is similar to that of Engelmann spruce. However, on a rotation of maximal mean annual increment, its volume yield per acre unit will be higher than that of Engelmann spruce, and it should yield a higher rate of return on invested capital. / Forestry, Faculty of / Graduate

The thesis had two main objectives: namely to provide information on the sound attenuating abilities of tree species of the lower mainland region of British Columbia and to ascertain what stand characteristics cause trees to attenuate sound. After an extensive literature review an experiment was designed to investigate sound attenuation in eighteen tree stands, comprised of four species, at three distances, for eight different sound frequencies. The exerimental work was done during the winter of 1969 and the summer of 1970. Prior to this the tree stands were enumerated and various tree parameters measured. No patterns could be found which significantly correlated the measured stand characteristics with the amount of sound attenuated. Little significant difference was found between the summer and winter attenuations and it was found that stands reacted independently of the season. Tables are presented in the Appendix showing the attenuations for each stand, at each distance and for each frequency. Mean values together with their standard deviations are given for all stands within a species. Suggestions are given for future work on this topic and the implications of the results on various design fields are discussed. / Forestry, Faculty of / Graduate

The patterns and rates of forest regeneration on a critical wildlife winter range on the floor of the trench, known locally as Premier Ridge were examined in this study. A nearby western wall of the trench was also investigated to ascertain the effect of elevation on forest regeneration and understory productivity. Forest regeneration in a community which has remained unforested for several as years has pronounced effects on the floristic dynamics and productivity of the understory. On Premier Ridge the greatest floristic change was a rapid increase in pinegrass and a. corresponding decrease in the abundance of all other grass species as the forest regeneration progressed. Forbs varied widely in abundance while shrubs were slower to react to changes in the overstory. Similar trends were observed on Estella Mountain. Productivity of the grass component on the unforested sites was four times that of the forested sites. The production of forbs and some species of shrubs also declined as forest regrowth began. One species, bearberry, increased under light forest canopies. The reduction in productivity and the changes in species composition of-the understory which occur in regenerating forest communities, appear to be detrimental to foraging populations of wild and domestic ungulates. Cattle seem to prefer to graze the open, unforested areas, and as regeneration proceeds, the acreage which they will readily use diminishes. Since there have been few reductions in stock numbers to compensate for this range shrinkage, local overgrazing has become more widespread. The regrowth of the forest reduces the grass, both in terms of quality and quantity. This is the most important component in the diet of cattle and most of the wildlife species using the Premier Ridge area. In addition, bitterbrush, used in the summer by cattle and during the winter by big game species, is quickly eliminated by forest regeneration. Bearberry, which may be used by wildlife to some extent, increases under forest cover. This component does not approach in value or usefulness, the losses that the other components represent to grazing animals. The trees of the south and southwestern aspects are characterized by relatively slow growth rates. Forage production on these slopes is modest; if grazing animals are deemed desirable in the future economy of the East Kootenay, these areas should remain treeless. Growth rates are more favourable on the north and northeast aspects, which are less frequently used as foraging areas by winter wildlife, but may be used as shelter or bedding areas. / Land and Food Systems, Faculty of / Graduate

Various criteria are discussed and as algorithms for obtaining optimal designs for use in linear regression. Linear regression is used widely and effectively in forestry but the method of quantifying the linear relationship in terms of selecting observations or designing an experiment to obtain observations is often inefficient. The experiment or study objectives must be identified to develop a criterion for comparing designs. Then a method of obtaining observations can be found which performs well under this criterion. Biometricians in forestry have been slow to take advantage of one of the assumptions of linear regression, namely that the independent variables are fixed. In part this has been due to limitations in the theory. Two important assumptions in most optimal design work, namely that precision requirements and costs are constant for all observations, are not valid for most forestry applications. Ignoring nonconstant costs can lead to designs less efficient than ones where each combination of independent variables is selected with the same frequency. The objective of this study was to develop a method of optimal sample selection that allowed for costs and precision requirements that vary from observation to observation. The resulting practical experimental layouts are more efficient for attaining the experimenter's objectives than randomly selected observations or designs constructed using the currently available design theory. Additional features of designs that consider differing costs and precision requirements are their larger sample size and their robustness to misspecification of the sample space. Traditional optimal designs concentrated observations on the boundaries of the sample space. By recognizing that these observations may be more costly and may not be of primary interest to the experimenter, more efficient designs can be constructed from less extreme observations. A computer program for obtaining optimal designs is also included. / Forestry, Faculty of / Graduate

This study presents the growth, yield and the silvicultural management of Cupressus lusitanica, Pinus patula and Pinus radiata, the three most important timber species growing in the Kenya highlands. The study Is based on 163, 176 and 164 permanent sample plots for the three species respectively. The stand dominant height development was predicted as a function of stand age and site index, defined as dominant height at reference age of 15 years. The Chapman-Richard's growth function was used for C. lusitanica and P. radiata while a linear quadratic equation was used to describe dominant height development for P. patula by geographical regions. Height development for the two pine species was found to be significantly different (up to age 20 years) in the Shamba and grassland establishment sites. Stand basal area before thinning was predicted as a function of stand age, dominant height and number of stems using a Weibull-type growth equation. In thinned stands basal area was predicted through a basal area increment nonlinear equation. For P. radiata, basal area increment was predicted as a function of basal area at the beginning of the growth period (1 year) and age. For C. lusitanica and P. patula, a third term-stand density index, defined as the percent ratio of average spacing between trees to stand dominant height was included. The Weibull probability density function was used to characterize stand diameter distribution with the Weibull parameters predicted as a function of stand parameters. Stand volumes were determined from tree volume equations for the respective species while the mean DBH of stems removed in thinnings was predicted from mean stand DBH before thinning and weight of thinning. Using the above functions, a growth and yield simulation model EXOTICS was constructed. Written in FORTRAN IV G-level which is compatible with IBM System/360 and System/370, EXOTICS is an interactive whole-stand/distance independent model with an added capability for providing diameter distribution (by 3 cm diameter classes) to give final main stand yield by size classes. The model is intended to facilitate silvicultural management of the three species in the Kenya highlands. On validation, EXOTICS was found to have no bias within the range of validation data, and 95% confidence limits of 16%, 20% and 17% for C. lusitanica, P. patula and P. radiata respectively. Using EXOTICS, the current silvicultural management schedules in Kenya were studied. The thinning regimes were found to have marked effects on the current annual volume increment. It was therefore concluded that at the present level of silvicultural management, Moller's theory that thinning has no appreciable effects on total volume yield does not hold for the three species in Kenya. The current thinning policy aimed at production of large-sized sawlog crop in as short a rotation as possible at the expense of some loss in total yield is discussed and found to have been overtaken by events. A policy based on the concept of maximum volume production is advocated. A thinning experiment (using C. lusitanica) demonstrated that total merchantable volume could be increased by between 5 and 10% (using 20% thinning intensity) depending on site quality class. Within the range of stockings maintained in plantations in Kenya, thinning intensity was found to be the most important consideration, with stocking before thinning having very little effect on both mean annual volume increment and total merchantable volume yield up to age 40 years. / Forestry, Faculty of / Graduate

Government funding for silviculture in British Columbia has expanded recently, but remains well short of the level recommended by many foresters. This thesis contains a proposal to replace government funding with investment from capital markets. It describes the funding mechanism, analyzes the implications to government, and introduces a method of distributing investment funds through a system of competitive bidding between forest management companies. In return for their participation, investors and forest companies would both receive equity in future timber production. The thesis concludes that at a cost of foregoing 50% of its future stumpage revenue, government might replace its current spending on intensive forest management with a funding level from capital markets of $500 million to $800 million per year. / Forestry, Faculty of / Graduate

Self-reliance in wood products is one of the major objectives of Kenya's forest policy; stated as the management of forest resources for the adequate provision of the needs of the country in timber and other forest products to meet the community's requirements, and where possible provide for exports. The implications of such a policy are such that strategies formulated, programmes designed and practices employed in production of wood resources and wood-based products should be geared towards the anticipated needs of the intermediate consumers, which in turn are only responding to the needs of the final consumers - the society. It is argued here that such production strategies, programmes and practices cannot be formulated and pursued to satisfactorily fulfill the policy objectives, without first identifying and understanding the needs of the specific target markets. Among factors identified as necessary in understanding the target markets are market structure, size, location and dynamics of consumption pattern-determining parameters such as time, demographic and economic factors. Using production and consumption data, primarily for the period 1960-1975, quantitative and qualitative methods were used to analyze and describe the various markets of wood products, as the basis of forecasting the probable future market trends. On the basis of current management and consumption trends, forecast estimates indicate possible internal wood supply deficits during, and beyond, the period 1996-2000 AD. Current and projected market trends indicate a progressive shift from mechanical wood industries and products, mainly sawnwood, towards fibre-based reconstituted wood products - fibreboards, particleboards and paper products. This projected development would tend to favour greater attention by forest management to the potentials of not only natural forests but species diversification of man-made forests. The fibre-based industries can satisfactorily utilize small-sized logs, hence shorter rotations, and a wide range of species composition since some of the products do not exhibit individually specific wood characteristics. Plantation-species diversity, in addition to avoiding the risks of possible loss in case of an epidemic, has the advantages of comparative climatic and zonal suitability in establishment. Trends indicate that fuelwood is, and for some time will continue to be the single major component of wood consumption, rising from about 15 million M³ (rw) by 1975 to about 30 million M³ (rw) per year by 2000 AD; yet forest management seems to have no supply strategy for this product. A major identified deficiency in forestry production-utilization-marketing as a system has been insufficient coordination in wood production management decisions with different industries' development programmes and anticipated market trends, and their requirements. Probable future wood supply-demand balances were comparatively estimated on the basis of potential supplies from current and planned wood production programmes and the projected markets. From the view point of wood production management decisions, medium and long-term market forecasts can be considered more meaningful than short-term needs, since the latter will have to draw from maturing stocks, while current and planned forest establishment programmes are the basis of future medium and long-term supplies. For this reason, emphasis has been laid on the medium and long-term forecasts, up to 50 years from now, or 1 to 2 production rotations. This analysis indicates that while management has placed emphasis on plantation forestry for industrial wood supplies, the strategy, despite its merits, is biased in favour of predominantly two exotic softwood species groups, comprising of cypress and pines despite the feasibility of producing wood supplies from potentially commercial and marketable indigenous species (mainly hardwoods) and other exotic hardwoods. While natural forests constitute about 92 percent and plantations 8 percent of Kenya's forests, little management effort has been directed at commercial wood production from the former, whose annual supplies average 20 percent of total industrial wood harvested. Quantitative and qualitative analysis of indigenous woods in natural forests indicates great commercial potential of these indigenous resources. There is a need for a shift from exclusive reliance on silvicultural considerations and wood production per se as the main criteria for production management, to a set of criteria that gives sufficient consideration emphasis on utilization and marketing requirements. Greater co-ordination between foresters, industries and marketers is required in the areas of research, development decisions, information gathering and dissemination, and wood resources allocation and sales to facilitate Production Planning for the target market needs. / Forestry, Faculty of / Graduate

This thesis provides empirical evidence to assess the long term contribution of the B.C. forest industry to the provincial economy. Estimates of resource rent are constructed to measure the direct contribution of the resource to provincial income and growth. Measures of rent are constructed for a firm level sample (1906-76) and at an industry level (1918-92). The figures for rent are used to generate estimates of the share of provincial income measures directly attributable to the industrial exploitation of the province's forests. While there were periods during which the direct contribution to provincial income and its growth was nontrivial, in general the growth of forest industry rent did not drive overall economic growth but rather lagged behind. Rent was low on average and volatile during the years before W.W.II, rose rapidly from roughly 1940-51, then declined unevenly. To investigate the forces which underlie both the broad trends and the variability in rent, a stylized model of the forest industry is applied in an empirical analysis. Broad changes in aggregate rent were the result of changes in rent per unit of B.C. timber. The rapid increase in rent coincided with a marked rise in the price of forest products. The secular decline resulted from the combination of a falling output price and rising costs. An investigation of real harvesting costs indicates that depletion played a role in this increase. The variability of rent is also explored and found to be most strongly influenced by factors reflecting market risk which the B.C. industry could not diversity away from. The rent measures may not capture the full impact of the forest industry, so the industry's potential role as a leading export sector is also examined. The possibility of a stable long term link between forest exports and provincial income is investigated using cointegration tests. B.C. forest exports and G.D.P. are not cointegrated; their levels axe not linked in a deterministic way in the long run. A bivariate VAR, is used to examine the short run interaction between the growth of forest exports and provincial G.D.P. The results do not strongly support the view that the forest industry acts as a leading export sector in the provincial economy. / Arts, Faculty of / Vancouver School of Economics / Graduate