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  • 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.
311

An economic approach to assessing the value of recreation with special reference to forest areas

Christensen, Jens Bjerregaard January 1985 (has links)
Different methods of estimating the value of recreational areas are discussed with particular attention being given to socioeconomic methods - the survey method and Clawson's method. Aspects of consumer's surplus and aggregating welfare measures have been dealt with. A Clawson method has been applied to empirical data from a forest area in Wales and data from a region in Denmark. In the case from Wales, it was found that 73% of all visitor groups in the sample were on holiday. In addition, for many visitor groups (48%) the visit to the forest area was just one part of the day's outing. Therefore, it was considered necessary to modify the Clawson method. Problems with the weighting of points for the trip demand curve have been given considerable attention. The data from Denmark give rise to consideration of the problem of substitute areas and a classification system was used to select population zones for the Clawson analysis. Different models for the trip demand curve have been tested and the exponential was found to be the most appropriate.
312

The history of forests and forestry in Wales up to the formation of the Forestry Commission

Linnard, W. January 1979 (has links)
No description available.
313

Trees and indigenous ecological knowledge about agroforestry practices in the rangelands of Shinyanga Region, Tanzania

Kilahama, Felician Bakamaza January 1994 (has links)
No description available.
314

Project appraisal under risk, threat and uncertainty : a case study of the afforestation project of Bihar, India

Shukla, Devendra Kumar January 1996 (has links)
In view of the Indian Government's growing commitment to forestry, a number of afforestation projects have been implemented. But most projects in developing countries do not conclude as per plan, uncertainty being a major factor. This study undertakes physical, financial, economic and social appraisal of the afforestation programme through case studies of the farm forestry (FF) and the rehabilitation of degraded forest (RDF) components and discusses the conceptual and methodological issues in appraisal of these projects under risk, threat and uncertainty. We have used three different approaches to risk appraisals in the present study. They are: the expected value of NPV through the illicit felling models; the cumulative distribution function comparisons through stochastic efficiency rules; the utility function of the project managers. Physical (logistic and Weibull models), financial and management decision (deterministic and probabilistic models) models developed in the study help in threat appraisal through quantification of physical loss, financial appraisal of its consequences and formulation of a management strategy under the threat of illicit felling. The risk analysis of the FF and the RDF component using Monte Carlo simulation is used to generate probability of return profiles and the results are compared through stochastic efficiency rules. The utility functions of the project managers are used to describe their risk attitude. The study shows that most managers are risk averse and the analysis of their utility functions supports the decreasing absolute risk aversion hypothesis. It emphasizes the need for a risk policy in the Forest Department. The economic appraisal examines the interaction of the FF and the RDF components with the economy rather than the treasury. Illicit felling is accounted for as a benefit to the economy. A 'Shadow pricing approach' is adopted for economic and social appraisals. For the social appraisal, inputs and outputs are estimated in terms of net discounted utility-weighted consumption flows. All the parameters of social and economic appraisal such as the consumption value of unit reinvestment, utility weight for incremental consumption at different consumption levels, social discount rate and economic discount rate are estimated. To study farmers' adoption behaviour, principal component analysis is used to explore significant factors and a logit model is developed after that to estimate probability of adoption. The study indicates that adoption of FF can be explained in an overall framework of evolutionary theory proposed in this study. The evolutionary theory posits that farmer tree growing can be considered as a land use strategy in response to both changing macro and micro factors, many of which relate to characteristics of the farmers, their resource endowments etc. It is concluded that success of projects can be assessed by taking account of the factors influencing the variability in the project outcome and understanding the whole process of people's interaction and participation in the project.
315

A knowledge-based systems approach to agroforestry research and extension

Walker, Daniel Harmen January 1994 (has links)
Agroforestry development programmes frequently rely on knowledge from a number of different sources. In particular, there is a growing recognition amongst development professionals of the value of augmenting partial scientific and professional understanding with the detailed knowledge held by local people. Taking advantage of the complementarity of local, scientific and professional knowledge demands the development of effective mechanisms for accessing, recording and evaluating knowledge on specified topics from each of these sources. The research described in this thesis developed a methodology for the acquisition, synthesis and storage of knowledge. The defining feature of the approach is the explicit representation of knowledge. This is achieved through the application of knowledge-based systems techniques. AKT2 (Agroforestry Knowledge Toolkit), a software toolkit developed in Prolog, an artificial intelligence programming language, provides the user with an environment for the creation, storage and exploration of large knowledge bases containing knowledge on a specified topic from a range of sources. The use of diagramming techniques, familiar to ecologists and resource managers through systems analysis, provides an intuitive and robust interface. This knowledge-based system drives incremental knowledge acquisition based on an iterative evaluation of the knowledge bases created. The iterative approach to knowledge acquisition provides a coherent, consistent and comprehensive, and therefore more useful, record of knowledge. Once created, knowledge bases can be maintained and updated as a record of current knowledge. Techniques for the exploration and evaluation of the knowledge base may be useful in : " giving research and extension staff access to a concise and flexible record of the current state of knowledge; " providing a resource and mechanisms for use in planning and prioritising research objectives; and " providing a resource and mechanisms for the generation of extension materials tailored to the needs of particular clients.
316

Ex-post cost-benefit analysis of village woodlots of Gujarat, India

Khan, Jamal Ahmad January 1993 (has links)
No description available.
317

The prediction of growth and wood quality parameters for plantation grown Pinus radiata D. Don. in New Zealand

James, R. N. January 1983 (has links)
Most of the wood harvested in New Zealand comes from plantations of the exotic species Pinus radiata D. Don. Because forest yield exceeds demand much of the expanding forest production is available for export. Analysis of the export potential for forest products has shown that wood quality will be important to market success. Yet there is concern that intrinsic properties will decline after 1985 with an inevitable reduction in rotation age. This work develops parameters which link silviculture to the two most important intrinsic properties, wood density and tracheid length. Both of these properties vary more or less regularly with geographic region. Within individual trees values depend on wood-age (= rings from pith). The properties of a stand of trees can be assessed if volume per tree can be partitioned into wood age categories. The parameter suggested here as best indicating wood quality whilst also having relevance to silviculture is volume of mature-wood, that is volume of wood age greater than ten years. A replicated spacing/thinning trial of 75, 0.06ha plots provided the data source. Models were developed to predict the wood quality parameter. Diameter growth is projected for a plot by means of an individual tree, distance dependent model based on multiple linear equations. Height is predicted from age and diameter by a system of homologous non-linear equations and volume per tree by a function of diameter squared and height. From diameter, height and age, mean wood age is predicted using a multiple linear equation and the distribution of volume by wood age is predicted using the Weibull function. The distribution is applied to each tree and totalled for the stand. Comparing results at a fixed age for a wide range of silvicultural regimes reveals that silviculture has a greater influence on wood quality than hitherto believed.
318

Working between art and forestry : towards an ecology of practices

Clarke, Jennifer January 2015 (has links)
This thesis is an anthropological inquiry into how art comes to be made in and about forests, and how forestry, art practice and anthropology could be mutually enriched. Drawing primarily on more than two years of fieldwork (2009 - 2012) it examines some of the overlapping interrelationships that emerge through working in the interstices between art and forestry in Scotland, by paying attention to the grounds of artists' and foresters' interests and practices as they operate in specific instances. This thesis also investigates pertinent aspects of forestry management such as forest design and landscape planning, as well as foresters' approaches to interpretation and the role of art in the context of public forestry in Scotland, considering the contemporary issues for the 'multi-purpose' management of such complex ecological and social systems. The points of intersection between the fields of art and forestry are axiological as well as practical. This thesis explores diverse ways of working in as well as with art and forestry, that in different ways are concerned with questions of agency, ethics, and aesthetics, ways of seeing, materials and material processes. It reviews different approaches to art, from more traditional examples of permanent sculptural works commissioned for public forests, to projects by artists whose work engages explicitly with the ethics and politics of working forests, and with people, as well as aspects of forestry management as I mention above. Moreover, my research also explores some of the correspondences between art and anthropology, and works towards one way of doing anthropology 'with' art rather than an anthropology 'of' art. This is revealed in correspondences between art and anthropology, which this thesis explores through practical and conversational experiments that chime with skilled ways of working in both art and forestry. While critical of the apocalyptic visions and utopian politics that often accompany ecological thinking, this thesis is correspondent with forms of contemporary ecological art praxis. The research is offered as a contribution to such ways of working, which reveal the interweaving political, philosophical and ethical implications of ecological perspectives.
319

Decentralising forest management in India : the case of Van Panchayats in Kumaun

Baumann, Pari Christina January 1997 (has links)
This thesis is an examination of the political settlement in Indian forest policy. In the last two decades the rapid degradation of Indian forests has led to a reconsideration of who should manage the forests and with what priorities. An agenda has emerged which identifies the decentralisation of resources to local communities for subsistence as a national priority. This thesis explores the content and development of the consensus over decentralised forest management. My focus in this respect is on a system of common property forest management in the Central Himalaya, and on two villages in District Kurnaun in particular. In chapter 1 argue that the content of agenda is determined by two interest groups, the government and 'a social forestry interest group', comprised of NGOs ahd the international development community. Both have theories about the interaction between environment and society in which their own specific interests are represented as being in the general interest of society as a whole. The 'conventional' position adopted by the government considers central control over local units of management necessary to prevent unrestrained resource use. The 'populist' position of the social forestry interest group maintains that common property regimes were a past tradition, and that their disruption - is a principle cause for deforestation. Both theories fail to explore the material causes for environmental degradation, and the way in which local communities have adapted their patterns of resource use and social relations of production in response to developments in the wider economy. In chapter 3, 5, 6 and 7 I show the inadequacies of populist and conventional explanations for the interaction between environment and society, and why the new agenda fails to offer a comprehensive agenda for development. In chapter 4 and 8 I consider the way in which the discourse over the environment has become entrenched in policy making.
320

Model-dependent sampling for timber value in old-growth forests of coastal British Columbia

Thrower, James S. January 1989 (has links)
The procedure used to sample crown timber before harvesting in B.C. is designed to estimate net volume per ha using systematically located angle-count plots where trees are selected with probability proportional to basal area. The primary purpose of the sample is to provide information for timber valuation and stumpage appraisal. Timber value is the most important population parameter for stumpage calculation, but it is not explicitly considered in the sampling design. The objective of this study was to modify the current sampling method to increase the efficiency for estimating value using model-dependent sampling theory. Eighteen model-dependent sampling strategies were developed from six subsampling methods using three estimators. The six subsampling methods were used to select trees from angle-count plots to estimate the relationship between cruiser-called and estimated tree value. Three subsampling methods used probability-based selection of trees and three methods used purposive-based selection of trees. Ratio, average ratio, and regression estimators were used with each method. The 18 strategies were tested using Monte Carlo simulation with 2000 samples at each of nine sample sizes in three test populations. The test populations were created by grouping angle-count plot data into mutually exclusive sets reflecting different stand characteristics. The sample sizes were n = 20,40, and 60 plots with m = n, 3n, and 5n subsampled trees. Individual tree value was estimated with regression equations that used variables closely related to the value of each species. The sampling strategies were evaluated for bias, sample variance, achieved subsample size, sampling cost, confidence interval coverage, and relative advantage against the current sampling method. The model-dependent subsampling methods using purposive selection of trees were more efficient than the current sampling method considering cost and variance. The purposive-based methods were biased up to about 5%; the probability-based methods were slightly less biased. The two most efficient methods were: i) purposive selection of trees with the highest estimated values in a plot; and ii) purposive selection of trees with estimated values within a given range to give a second-stage sample balanced on the auxiliary variable. The greatest efficiency was always achieved with one sample tree per plot. The current sampling method was unbiased for estimating value but required approximately twice as many plots to estimate value to the same level of precision as net volume. / Forestry, Faculty of / Graduate

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