This thesis is concerned with questions relating to the optimal regulation of logging in a solely owned forest. Optimal is taken to mean maximizing the present value of net revenues obtainable from growing and harvesting an infinite sequence of crops on a piece of forest land. Discussions of optimal harvesting usually assume there is no advantage to changing the age distribution of a forest. This is also the assumption of Chapter I. In this case, trees are cut when their age reaches the rotation period which is determined from what is called the Faustmann formula. Chapter I looks at the comparative statics of these rotation periods. The effect of a change in an exogenous parameter on the rotation period is shown to depend on how certain elasticities are changed. It is then shown that there are conditions under which these results extend to a more complex forestry model where the manager chooses the level of effort to be expended on regeneration and silvicultural activities. The techniques used are drawn from optimal control theory. Chapter II introduces considerations which may make it advantageous to alter the age structure of a forest while logging it. In particular, a variable average cost of harvesting function is allowed for. A forestry maximum principle is derived which determines the dynamics of optimal harvesting. This is similar to the maximum principle for processes incorporating a delay (the time between planting and harvesting). The usual growth theory questions are then asked. In the variable average cost case, the "steady state" age distributions turn out to be "normal" forests with the time between harvests being determined by a Faustmann formula Global asymptotic stability is not proven but is shown to be likely. Finally, Chapter III applies the forestry maximum principle to a problem of determining an optimal harvesting policy for a group of forests subject to a sustained yield constraint. Assuming stability and with a few additional restrictions, it is shown that the optimal long run policy is to convert each separate forest to a "normal" forest. The Faustmann formula determines the number of age classes in each forest. / Arts, Faculty of / Vancouver School of Economics / 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

Smallholder tree cultivation and management is a common form of land-use in high potential areas of Kenya. Some practices, such as the planting of trees on field boundaries are strongly rooted in customary notions of land and tree tenure. Others, such as the planting of black wattle (Acacia mearnsii) woodlots, are more recent innovations, introduced to produce commodities for domestic and export markets. This thesis explores the historic, cultural, and economic dimensions of tree growing in Kenya, using archival and ethnographic data, land-use surveys, and results from a survey of 123 households in the upper coffee/lower tea zone of Murang'a District. The household survey was designed to explore the hypothesis that tree growing complements formal employment as a strategy for overcoming poorly operating factor markets and helps to ease land-use constraints imposed by labour migration. Tree planting is favored because of its low capital and recurrent costs and when farmers are unable to plant other more resource-intensive crops. The survey focused on households which currently maintain a black wattle woodlot and on households which operate parcels which were used for growing black wattle in 1967, but which have since been cleared and are being used for growing something else. The survey showed that woodlot growing households operate larger parcels, are older, support fewer residents, and have more non-resident relatives than other households in the survey. Woodlot growing parcels are also at a lower altitude and are more steeply sloping than other parcels. Patterns of resource allocation suggest that woodlot growing households are more risk averse. Logistic regression (logit) modeling explored causal relationships, suggesting woodlots are indeed more likely to be established as households age and as labour becomes scarce, and that woodlot clearance takes place when labour is more available to cultivate the holding.

Graduation date: 1978

Economic growth or development, the process by which a nation gains wealth, is analysed in Part I. So far there is no theory which fully explains the phenomenon of sustained increases in the per capita income of a country. Probably, development is possible only if many economic and non-economic variables have values within certain relative ranges, which should be the subject of further study. In this thesis a dynamic consumption function has been postulated and used to construct a simulation model to help guide an economy's approach to sustained economic growth. Computer analyses with the model show the changes in per capita income as an economy approaches the "take-off" stage. They also suggest that, due to different existing values of the relevant variables, each country may find its optimum method of development to be different from others. It seems that early and large imports of foreign capital (a minimum of about 10 per cent of GNP annually), or a comparable reduction in personal consumption, are needed to initiate economic development. In Part II analyses indicate that a limited role can be played by forests in the poorly understood but urgently sought process of economic growth. Under usual circumstances, forests can help the economy move towards the take-off stage and meet the requirements created as development proceed. Forests, like any other resource, are important for development and human welfare. But, society must forego something when it uses any one resource. Foresters have often looked only at the benefits from forestry. It is essential to consider also the costs involved in using forests. The costs are in the form of missed opportunities to use forests fully or to replace them with a substitute for forest products. This thesis helps evaluate the role that forestry can play in economic development. The widely accepted principle of sustained yield forest management has been criticized. The principle of maximization of the present worth of net benefits from forest land is suggested as a desirable alternative. Forestry is different from other sectors in that (1) wood is its product as well as the major part of capital, (2) the period of production is long and (3) the product is very versatile. Forestry is suitable for being given priority in a national or regional development plan because it can (1) efficiently utilize under-employed rural resources, (2) produce important raw material for making paper which is necessary for human investments, (3) substitute for imports and earn foreign exchange in today's underdeveloped countries, (4) provide fuel and release cow dung for use in agricultural fields in some parts of the world and (5) serve as the basis for regional development where forests are plentiful. Commonly, if plans changes, wood grown for one purpose can be used easily for another. Most of these characteristics have been recognized by forestry economists but their studies have usually been based on historical evidence rather than analysis of possible future development. The future importance of forestry depends on its technological progress in relation to other sectors which are potential rivals of forestry. Forests can facilitate development and also help maintain economic growth. As per capita incomes rise, demands for forest products increase. Forest products needed to initiate and sustain development can be supplied best by managing forests in such a way that the present profits from forest property are maximized without detriment to the present worth of future profits. Profits then should be used for investment in the most economically desirable fields. It is shown that revised user cost concepts can be applied in forestry, These determine the optimum rate of forest harvesting and the amount of investments to be made in the present so that the present worth of the forests is maximized. Further refinements of decision theory are needed to solve the complex problems involved. Because there are many substitutes for them, only the most economical forest products will remain important in the long run. Forestry's role can be enhanced most effectively if foresters improve the technology employed in growing and utilizing forests. Finally, policy implications for underdeveloped countries in general, and India in particular, have been discussed. It is concluded that the policy of rigid sustained yield forest management should be rejected. It should be replaced by maximization of present worth of net benefits from forest land in each management unit. Then, forestry can play its maximum possible role in economic development. / Forestry, Faculty of / Graduate

In I968 the B.C. Forest Service provided growth and yield data in the form of nearly seven hundred volume/age curves. These were summarized quantitatively and sorted by electronic computer. Summaries were used for study of the criteria determining rotations in British Columbia. At the same time an assessment of these curves for other uses in forest land management was made. The curve summaries illustrated the need to consider differences in region,species, or growth type, site class and utilization standards. It was shown that a direct, negative correlation exists between rotation length and site index. This was done using the physical criterion which determines the rotation age at the culmination of mean annual increment in cubic foot volume. Because simple volume over age curves do not provide some important data such as numbers of trees per acre and average stand diameter, the study showed how several rough estimates of these would be derived theoretically. No positive conclusions could be drawn. The exercise did show, though, that the use of actual data describing stand density for fully stocked stands would benefit the forest land manager to a remarkable degree. The next step involved an assessment of the available financial alternatives to physical rotation determination, then compared them with approaches employed by two representative agencies in British Columbia. The possibility of using average stand diameter as a means of approximating the financial rotation was indicated. B.C. Forest Service volume/age curves now are useful as a tool of forest land management. They could be improved by the provision of information to define growth behaviour at full stocking, given various levels of stand density. Another conclusion was that the forest manager using the optimum accounting rate of return (single year) investment criterion and the economist using time preference criteria both have the same objective, namely the most efficient use of capital. This objective is more likely to be achieved by the manager in a series of Intermediate steps. At the same time the economist's time preference may span a single rotation. It was recommended that the B.C. Forest Service continue to develop forecasts of average stand diameter with their yield predictions as a means of introducing the financial implications of a chosen rotation. / Forestry, Faculty of / Graduate

This thesis describes an optimization model for the allocation of logs from alternative sources for a series of successive time periods. The model was formulated as a multi-stage decision process and is solved by dynamic programming. The analytic framework consists of two connected recurrence equations, each incorporating two decision-variables. These two relationships, together with the feasibility regions defined for a hypothetical problem, describe the optimization process. The hypothetical allocation problem, used as a vehicle for model development, requires mill demands for quantities of pulplogs and sawlogs to be satisfied for three time periods. Logs are delivered from five available sources, four log-producing areas and an open log market, and temporary log surpluses are allowed. Only a limited quantity of logs is available from each source in each period, two of the four forest areas supply only pulplogs and a third area is inaccessible in one period. The variable unit costs of delivered logs differ not only between each source and period but are also dependent upon the magnitude of an allocation. In addition to satisfying mill demands for specified quantities of logs, there is a further requirement with regard to sawlogs. Average lumber prices are assumed to be dependent upon the tree species processed and variable log conversion costs are assumed to decrease with increase in log diameter. Consequently, the comparison of alternative allocation policies involves not only the sum of the variable delivered log costs but also a measure of the value of delivered sawlogs. In the thesis "sawlog net worth" is evaluated and combined with log production and log transportation costs to give a composite cost term, "net delivered log cost." This is the measure used to evaluate each allocation and is incorporated in the first of the two recurrence equations. This equation is used to derive minimum cost allocation policies for all possible quantities that may be allocated from each period. In the second equation the minimum costs derived from the first allocation process are combined with a second term to evaluate alternative allocations between periods. This second cost component is incurred when surplus logs are "cold-decked" for subsequent mill conversion. To ensure a sufficient flow of logs, and to take advantage of seasonal differences in "net delivered log costs," log surpluses are permitted. When log surpluses are "cold-decked" additional log handling costs are incurred which must be considered when alternative allocations between periods are evaluated. This requirement is satisfied by introducing the additional cost component into the second equation. The different derivations given for the "net delivered log costs" for five sources of logs demonstrate an important feature of the formulation: there is no requirement that costs must be linearly related to the quantity allocated. This freedom is well illustrated by the introduction of additional "fixed" costs which are dependent upon the magnitudes of the quantities allocated. In a demonstration of the flexibility of the formulation a complex log production system was assumed for source two. For each allocation from this source two optimal quantities were derived. The first was the quantity of sawlogs selected from specified log classes, the second was the optimal portion of the quantity of peeler logs developed that should be traded. An exchange could be made either for sawlogs, or for pulplogs, or both. With the development of this log allocation model a fresh approach to log production planning is now possible. The analytic framework is capable of extensive adaptation and the model itself can be readily modified to suit a variety of conditions. Whether used as described, or as part of a larger analytical system, the computational advantages of dynamic programming are now available to the planner. / Forestry, Faculty of / Graduate

There is interest in forest sampling methods which have the ability to provide reliable estimates of volume without incurring unreasonable costs. Fraser (1977), to this end, described an individual tree variable probability sampling method which selects sample trees with probabilities based on the areas of polygons derived from triangles. A comparison of some alternative methods of sampling these polygons confirms Fraser's work and demonstrates that the method proposed by him probably has the greatest potential for practical forest sampling. / Forestry, Faculty of / Graduate

"June 2002" / Bibliography: leaves 258-273. / xii, 299 leaves : ill., map ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis considers the feasibility of incorporating financial estimates on the non-market values of environmental impacts from the forest management of public sector forest organisations into a financial environmental reporting system. Estimates of non-market values are possible using techniques from environmental and resource economics such as the contingent valuation method, the travel cost method and choice modelling experiments. / Thesis (Ph.D.)--University of Adelaide, School of Commerce, 2002

For many resource-based communities throughout Oregon the timber industry plays an important role. In many of these areas, federal land holdings comprise a large proportion of the area's land holdings. Management decisions regarding resource use on the National Forest lands can have a major influence on the stability of local timber industries and on the communities of which they are a part. Input-output analysis has been used extensively to evaluate the importance of the timber industry to relatively small resource-dependent communities. In the past, the conventional input-output demand model has been used to assess the local impacts of changes in the availability of public timber resources. However, an analysis which interprets a change in primary resource supply as a change in final demand for the processing industry's output may incorrectly evaluate the impacts of shifts in primary resource supply on the local economy. The regional economic impacts resulting from a change in available primary inputs can be estimated more accurately using a modified approach to the conventional method of demand-pull analysis. Because of the network of forward linkages present within the regional economy, a change in primary inputs available to one sector may have a direct or indirect affect on all other sectors of the local economy. These supply-induced impacts on total sales can be calculated using an input-output supply model. The resulting change in total sales can be factored into two components--sales to local industries and sales to final demand. Regional impacts resulting from the first component can be calculated directly from the supply model. A modified version of the input-output demand model can be used to estimate the regional impacts associated with the supply-induced change in the value of local industry exports. This study identifies and evaluates the forward linkage structure present in small resource-based economies. The conventional input-output demand model is modified so that the local impacts of changes in primary resource supply can be evaluated vis-a-vis these structural relationships. A comparative economic impact analysis of three eastern Oregon counties is conducted using the modified input-output methodology. The results obtained using this procedure are compared to results obtained using the conventional method of analysis where changes in primary resource supply are extrapolated to reflect changes in final demand. In each county, estimates of regional impacts obtained using the modified input-output methodology differed from those calculated using the traditional form of analysis. The difference between the estimates was most significant in Morrow County where a relatively larger percentage of output in the wood products industry is sold locally. The demand-induced impacts in each county were considerably larger than the supply-induced changes. Although the initial shock to the system is supply-induced, the backward linkage structure plays a significant role in determining the overall impact of the stimulus on regional and sectoral output. The supply model is able to account for the direct and indirect impacts on regional sales transactions caused by a change in available primary inputs. The input-output demand model, by itself, is unable to account for these transactions. Because the modified input-output methodology provides a means by which changes in scarce primary factor supply can be apportioned into supply and demand related components, a better understanding of the regional economic impacts associated with changes in the availability of public timber can be obtained. / Graduation date: 1982