• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 27
  • 1
  • Tagged with
  • 28
  • 28
  • 28
  • 21
  • 10
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Survey of forest regeneration in the Nimpkish Valley of British Columbia and recommendations for future management.

Bunce, Hubert William Ferdinand January 1960 (has links)
Logging has proceeded continuously since 1915 in the Nimpkish valley. The cutting has been of the old-growth Douglas fir (Pseudotsuga taxifolia (Poir.) Britt, western red cedar (Thuja plicata Donn.), western hemlock (Tsuga heterophylla (RAF.) Sarg.) and balsam fir (Abies amabilis (Bougl.) Forbes. Many of the areas cut have become restocked naturally with various species of trees which are classified as second-growth. The excess of low-value trees and the slow rate of regeneration are not economically satisfactory. Since 1924 various plantations have been established. A study of the results of this natural regeneration and this artificial regeneration indicates practical methods for future procedure. Additional information comes from experiments that have been completed, and from those that are still in progress. The synthesis of the collected material and the silvicultural discourse form the basis for recommendations for future management of forestry operations in the Nimpkish valley. / Forestry, Faculty of / Graduate
2

An economic history of forestry in British Columbia

Yerburgh , Richard Eustre Marryat January 1931 (has links)
No abstract included. / Arts, Faculty of / Vancouver School of Economics / Graduate
3

Report and preliminary working plan for the University forest

Allen, George Samuel January 1935 (has links)
No abstract included. / Forestry, Faculty of / Graduate
4

The effect of some British Columbia forest tenures on the distribution of economic rents, the allocation of resources, and the investments in silviculture

Luckert, Martin Karl January 1988 (has links)
Canadian forest tenures serve as policy tools which have important economic implications. This study analyzes the effect of some British Columbia forest tenures on the distribution of economic rents, the allocation of resources, and silvicultural investments. The thesis first identifies the problem governments face, as landlords, in attempting to specify an optimum tenure. Tenures may be described in terms of packages of individual characteristics, each of which may be controlled, to varying degrees, by governments. The problem governments face is choosing an optimal combination of specified characteristics. Several problems emerge in the specification of individual tenure characteristics and their aggregation into whole optimum tenures. The specification of any one optimum tenure characteristic requires political value judgments implicit in social welfare functions. Furthermore, interdependencies exist between tenure characteristics which make difficult the aggregation of optimally specified characteristics into an optimum tenure. The interdependencies between tenure characteristics provide the basis for two hypotheses. First, every tenure characteristic may influence the benefits of tenure holders. Second, tenure holders may expect their tenures to change, which may influence the future benefits that they receive. By testing these hypotheses, the effect of tenures on the distribution of rents and allocation of resources are analyzed. To test these hypotheses, tenure holders in British Columbia were interviewed to obtain empirical measurements of the effects of attenuations of tenure characteristics on benefits of tenure holders, and the security tenure holders perceive in their tenures. Results support both hypotheses and show how tenures are distributing rents and allocating resources. The study also investigates the effects of tenures on investments in silviculture. Tenure holders in British Columbia are surveyed to determine amounts spent on silviculture on selected tenure types. It is found that tenure holders which have incentives for voluntary investments in silviculture spend significantly greater amounts than those who make expenditures which are reimbursed or mandatory. Using the results of this study, recent changes in British Columbia forest policy are critiqued and areas for further research are identified. / Forestry, Faculty of / Graduate
5

Aspects of forest resource use policies and administration in British Columbia

Kelly, Elizabeth Fay January 1976 (has links)
Having made the fundamental assumption that policy administration can be viewed as a process the question is then raised: In what ways and to what extent does the administrative process affect forest resource use policies in British Columbia? It is noted that the three basic policy principles have been since early this century: (i) public ownership of forest lands; (ii) a return to the Provincial Treasury of a proportion of the wealth of the forests as it accrues; and, (iii) extension of the useful life of the forests for the benefit of future generations. Using as a principle data source a large body of statutes, administrative documents and evidence and reports of commissions of inquiry accumulated during the past seventy-five years the thesis focuses on the administrative process with respect to three major aspects of forest resource policies in British Columbia. They are: land tenure systems, sustained-yield management of forest areas and royalty and stumpage assessment methods. The research confirms the validity of the basic assumption. In response to the above question several major points are made. Provincial land ownership policies and their administration have been significant in directing forest resource use administration and have had the affect of obscuring forest resource use policy principles themselves. With respect to the sustained-yield management programme in British Columbia the administrative process has affected forest resource use policies by giving administrative definitions to some of the basic terms used in the initial policy formulations. In the area of royalty and stumpage assessments methods it was found that administrative feasibility, which has been especially influenced by forest technology, has been a significant factor in determining the ends actually pursued by the administrative system and thus formally stated policy objectives have been modified. Overall the affect of the administrative process on forest resource use policies in British Columbia has been widespread and far reaching. / Arts, Faculty of / Political Science, Department of / Graduate
6

A least squares analysis of inventory data to compare yields of pure and mixed stands in British Columbia forest zones

Yang, Richard C. January 1978 (has links)
The author developed a statistical procedure to analyze irregular, unbalanced inventory data by the least squares principle. The method is found useful in forestry where data collected are often unbalanced in nature. It provides a unique means to incorporate qualitative as well as quantitative variables in forest yield analyses. Inventory data for three major species — Douglas-fir, spruce, and lodgepole pine were analyzed in connection with the study of growth and yield of pure (81% or more of the overstory is of a single species) and mixed stands in up to 12 B.C. forest inventory zones in which they occurred. More than 50% of Douglas-fir, spruce, and lodgepole pine stands occur naturally in pure stands. If there are any adverse effects on the establishment of pure stands, these should have been well reflected quantitatively in the data provided by the B.C. Forest Service. Estimates of site index from the inventory data might support that pure stands deteriorate soil conditions; however, the higher site indices in mixed stands may be attributed to the better site conditions when the stands were originally established. Mixed conifer stands tend to grow more trees per acre than pure or hardwood mixed type stands. Among the three species investigated, Douglas-fir required more growing space than the others. The relative stand density based on basal area per acre also indicates that stand density is higher in conifer mixed stands than in pure or hardwood mixed type stands. The mean annual increment is higher in hardwood mixed stands than in pure or conifer mixed ones. But stand age in hardwood mixed types is much less. The mean annual basal area increment of conifer mixed stands is consistently higher than that of the other two types. Zonal variations in the mean annual basal area growth are apparent. The mean annual volume increment follows a trend similar to that of the mean annual basal area increment. Douglas-fir stands growing on the Coast and in the Interior were compared. Mean annual volume growth is 84.00 cubic feet per acre for the Coast stands and 25.53 cubic feet for the Interior stands. The effect of species composition on net volume yield is significant in Interior Douglas-fir stands, but non-significant in Coast Douglas-fir, Interior spruce, and Interior lodgepole pine stands. That the effect of forest inventory zones is highly significant in the Interior Douglas-fir, spruce, and lodgepole pine stands justifies the zonation unless adjustments are made for stand density. Interactions for types and zones are significant in the Coast Douglas-fir, the Interior spruce, and the Interior lodgepole pine stands but are nonsignificant in the Interior Douglas-fir stands. The difference in yield in the Interior Douglas-fir stands is attributable to species composition types and forest inventory zones alone. The establishment of Douglas-fir conifer mixed type stands in the Interior effectively increases forest productivity by 21%. Interpretations of the interactions lead to the conclusion that the advantages of monocultural or multicultural practices cannot be over-generalized. Pure type stands are more productive in some zones but less in the others. The same is true for multicultural practices. Growth of forest trees is essentially site-dependent. Before a decision is reached on what species composition type to establish,, foresters should carefully investigate the local site quality and past yield history of various forest types to ensure that the maximum potential productivity of a particular site can be realized. Further analyses to test the hypothesis that no differences in volume yield exist among three species composition types for stands growing on same site conditions reveal that the effects for species types and inventory zones as well as interactions thereof are not significant for Coast Douglas-fir, however, for Interior Douglas-fir stands, the effect of species composition is significant. It is shown that on similar site conditions, Douglas-fir conifer mixed stands yield substantially more than pure or hardwood mixed stands in the Interior. The species composition effect is not significant in Interior spruce stands while zonal effects and interactions for types and zones are significant. In Interior lodgepole pine stands, effects of composition types, zones, and interactions thereof differ significantly. In all three species groups investigated, that the effects of hardwood mixed type consistently shows negative 'values implies that hardwood mixed type stands are the least desirable stand composition structure for these species in the Interior. Differences in volume between pure and mixed type stands result primarily from the inequality in basal area per acre. The variables, height x basal area and basal area are most important in yield table analyses. In addition, stand age, relative basal area, and forest inventory zone are all highly significant in contributing to the variations in volume yield of the Coast Douglas-fir stands. For Interior Douglas-fir, the most significant variables are, in addition to the above two variables, stand age, and relative stand density. Effects of species composition type and forest inventory zones are non-significant. For Interior spruce, the prominent variables in yield table analysis are height x basal area, basal area, species composition, stand age, height, and relative stand density. All variables being equal, pure spruce stands outyield stands of mixed spruce-hardwood and mixed spruce-conifer. The results provide good evidence that establishment of pure spruce stands is more desirable than of spruce and conifers or hardwood mixed stands. For lodgepole pine, the most significant variables in yield tables analysis are height x basal area, species composition types, and forest inventory zones. The high significance of zonal effects suggests that a separate yield table for lodgepole pine in each zone is warranted, unless appropriate adjustments are made for site index and stand density. Yield of pure lodgepole pine stands exceeds those of lodgepole pine conifer mixed type and lodgepole pine hardwood mixed types. Therefore, for high yields the establishment of pure lodgepole pine type stands is preferred. Application of these methods to the temporary sample plot data has clearly demonstrated the widespread distribution of pure stands and lack of substantial effects of monocultures on yield. Nevertheless, the fact that higher yields may result from some multicultures should encourage establishment of long term studies of spacing and mixtures of species. / Forestry, Faculty of / Graduate
7

Forest floors near Port Hardy, British Columbia, Canada

Quesnel, Harold January 1980 (has links)
The forest floors of three biogeocoenoses, from northern Vancouver Island, were stratified into LF and H horizons, sampled by use of a stratified random sampling procedure, and analyzed for a number of chemical properties. The biogeocoenoses represent Xeric, Mesic, and Hygric sites. The objectives of the study included: characterization of the forest floors in terms of chemical properties, estimation of property variation and sample requirements, selection of properties best suited for distinguishing the forest floors and organic horizons of each site, and examination of nutrient relationships within the forest floors. To assess variability of chemical parameters, 28 properties were used. The values for total nitrogen, iron, manganese, and exchangeable aluminum were found to increase from Xeric to Hygric sites. Increased leaching losses of potassium and calcium and accumulations of iron, aluminum, and manganese occur as the forest floor materials decompose. The least variable horizon in terms of overall sample requirements was the Mesic LF, while the most variable was the Hygric H. The LF horizons on all three sites tended to be less variable than the corresponding H horizons. The chemical properties found to have the least variability were considered to have the best potential for classifying forest floors. These were pH(H₂0), water content of an oven-dried sample, pH (0.01 M CaCl₂), loss on ignition, total carbon, pH (1 N NaCl), and cation exchange capacity measured at pH 7. Least value for prediction of variability and thus for classification were properties such as total manganese, aluminum, iron, calcium, sodium, thickness, exchangeable calcium and magnesium displaced by 1 N NaCl and 1 N NH₄OAc. The second phase of the study selected properties that were best suited for separating the organic horizons and forest floors of the three sites. The properties examined included those measured in the variability study as well as 12 derived or calculated parameters. Two-way analysis of variance in combination with the Student-Newman-Keuls range test was utilized to determine which parameters would best distinguish the forest floors of sites, the LF and H horizons overall, and the horizons of individual sites. The best properties found to separate Xeric, Mesic, and Hygric forest floors were total potassium, exchangeable sodium measured at pH 7, and the ratio of loss on ignition to total carbon. The best parameters for separating LF and H horizons were total potassium, total zinc, exchangeable calcium displaced by 1 N NH₄OAc, exchangeable potassium displaced by 1 N NH₄OAc and 1 N NaCl, pH measured in water and 0.01 M CaCl₂, loss on ignition, base saturation at pH 7, the ratio of total calcium to total magnesium, and the ratio of total calcium to total potassium. The horizons of the individual sites could not all be separated by any individual parameter. The univariate analysis indicated that the order of increasing difficulty of characterization was the LF and H horizons overall, the forest floors of sites, and the horizons of individual sites. A multivariate analysis was performed to find the combination of variables which best distinguishes the horizons of individual sites. Stepwise discriminant analyses using nine, five, and two variables correctly classified 94%, 81%, and 71%, respectively, of the cases examined. The best approach for using multivariate characterization would be to use a minimum number of variables and to include the parameters total nitrogen, potassium, phosphorus, the ratio of loss on ignition to total carbon, and cation exchange capacity measured at pH 4. The final phase of the study examined nutrient relationships in the forest floor horizons as well as the impact of decaying wood and fine roots on forest floor properties. A correlation matrix was produced for the LF and H horizons. The correlation matrices indicated that certain groups of properties were highly correlated and that only one form of the nutrients calcium, magnesium, and potassium need to be measured. The iron, aluminum, and manganese values were highly correlated, which shows that these elements are involved in similar processes, such as biocycling and podzol formation. Several other highly significant correlations indicate that the nutrients calcium, magnesium, and potassium are predominantly in exchangeable forms and that calcium is the dominant cation in these forest floor systems. .Time available for decomposition is the main factor distinguishing LF from H horizons. A final relationship to be examined was the pH-dependent cation exchange capacity. The values for this property increased significantly downslope and significantly greater values were found in the H horizons of each site - a result of increased functional groups associated with the formation of humus. The total nutrient concentrations of decaying wood were measured and compared to the concentrations found in the corresponding LF and H horizons. The decaying wood was found to be a nutrient-deficient material that is distinct from both LF and H horizons. Bulk density measurements demonstrated that the forest floor and decaying wood materials are not significantly different, although the latter material is more variable. .Therefore, decaying wood represents a substantial input of nutrient-deficient biomass to the forest floor. The nutrient concentrations of fine (<2mm) roots were compared with the values obtained for the associated decomposing organic matter. The fine roots were found to be relatively deficient in nitrogen in comparison to the forest floor. Elements such as iron, aluminum, magnesium, and sodium were found to be concentrated in or near fine roots. Thus, decomposing fine roots yield a significant input of nitrogen deficient biomass, cause an increase in the concentration and variability of certain elements, and play an important role in processes such as biocycling and pedogenesis. / Land and Food Systems, Faculty of / Graduate
8

Identity, culture, and the forest: the Sto:lo

O'Neill, Amy 05 1900 (has links)
I offer some tentative thoughts on Sto:lo relations with the forest and, in turn, suggest how those relations may inform Sto:lo views on identity and culture. While highlighting the variety and complexity of Sto:lo attitudes toward the forest, I pay particular attention to those that appear contradictory. In so doing, I suggest that such "contradictions" are instead necessary antagonisms that spring from the constantly changing pressures to which the Sto:lo have been subjected, as well as from the ways in which they have struggled to cope with such pressures. More specifically, in pointing to Sto:lo attitudes towards forest work and forest conservation, I suggest that the Sto:lo have been forced and even encouraged to make claims to their identity that do not, and need not, conform with what is considered "traditional." In this way, my discussion is structured around the relationship between a sense of Sto:lo identity and the notion of cultural continuity, while aimed at highlighting the material as well as the intellectual realities behind that relationship. In a broader context, my discussion is aimed at reinforcing the need for more flexible examinations of Native identity; those that will highlight what it means to live in a modern Native culture, and what it means to be vulnerable to power.
9

Problems of thinning and small log handling in second growth western hemlock stands with special reference to the research forest on East Thurlow Island

Adamovich, Lazlo Leslie January 1962 (has links)
Diminishing virgin timber on the Coast of British Columbia leads to consideration as to how management of the second-growth forests will supply the timber industry with a sufficient quantity of good quality raw material in the future. One of the possibilities would be intensive forest management supported by thinnings. The stands of western hemlock (Tsuga heterophylla (Rafn.) Sarg.), which comprise the largest area on the Coast, may be suited to this treatment because of their advantageous silvicultural characteristics. Little information exists on proper methods of thinning these hemlock stands. In addition, experience in logging methods and means of economically handling small logs are lacking. Among the few experiments which have been established to study thinning of hemlock, one is located on East Thurlow Island where nearly pure stands of hemlock occur. The Research Forest on the Island was scheduled to become an experimental and demonstration area for the study of thinning techniques. Studies under way on that area have shown that the methods used, had limited economic success. Commercial thinning operations turned out to be unprofitable partly because there was no adequate road system available for logging. Thinning problems in general, as well as the particular aspect of thinning western hemlock and the methods of handling small logs are discussed in this thesis to illustrate the basic problems involved in a development plan for the Research Forest. Finally, this thesis presents a general road development plan for the Research Forest area and proposes a preliminary management and logging plan. Through cost analysis it is shown that the basic access road system can be constructed economically during a preparatory period by clearcutting scattered overmature stands. Subsequent thinning experiments can be based on that road network. The approach to these problems is general rather than specific because there are few detailed data available from past experiments. / Forestry, Faculty of / Graduate
10

A comparison of methods of determining the allowable cut on the University of British Columbia research forest, Haney, B.C.

Kovats, Miklos January 1962 (has links)
Generally it is not adequate to calculate an allowable cut for a property by only one formula or method. Usually it is preferable to utilize all the information available with as many suitable formulae or methods as possible to obtain reasonable estimates of the yearly utilization rates by several approaches. For the University Research Forest fifteen different formulae and methods were selected for comparison, because their basic assumptions appeared applicable to this forest. The methods and formulae tested were: Methods: Area regulation, Area-volume check, Area-volume allotment, Barnes’ and H. A. Meyer's. Formulae: Austrian, Black Hills, Grosenbaugh, Hanzlik, Hundeshagen, Kemp, W. H. Meyer, S. Petrini (compound and simple interest) and Von Mantel. Appropriate inventory techniques were developed in order to collect the necessary information regarding rates of growth, mortality and numbers of trees per acre by diameter classes. Present and future decadal growing stocks were estimated. Simple and compound growth rates, including and excluding ingrowth, for all types were calculated separately for stands over eighty years of age and for stands under eighty years. The inventory was based on the areas and estimates taken from 1961 aerial photographs supplemented by both temporary and permanent sample plots, employing primarily the principles of the point sampling techniques as described by L. R. Grosenbaugh. After substituting the actual data into the formulae and various methods, allowable cut estimates for 3.1, 9.1, 11.1, and 13.1 inches minimum diameter limits were calculated. Allowances were made for an intermediate standard of utilization and for waste, breakage and decay. Considering the inventory and the allowable cut calculations it was found that: 1. Simple area regulation will lead to undesirably large fluctuations in allowable cut. 2. Volume formulae are useful means of determining the yearly harvest volume, though the distribution of the cut on the ground requires definition in terms of area as well. 3. Neither area nor volume control can be used exclusively. Some combination and integration is usually necessary in actual practice. In the case of the Research Forest this can be applied most conveniently by following the area-volume computation basis. / Forestry, Faculty of / Graduate

Page generated in 0.0914 seconds