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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.
41

Conservation through management : cut wood as substrate for saproxylic organisms /

Lindhe, Anders, January 2004 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.
42

Recreation allocations on national forests the claims and frames of recreationists /

Adams, John C. January 2009 (has links)
Thesis (PHD)--University of Montana, 2009. / Contents viewed on April 9, 2010. Title from author supplied metadata. Includes bibliographical references.
43

Current and future economic impact of Mount Hood National Forest outdoor recreation consumption /

Anderson, David M January 1991 (has links)
Thesis (M.S.)--Oregon State University, 1992. / Typescript (photocopy). Includes bibliographical references (leaves 80-89). Also available on the World Wide Web.
44

The process of forest conservation in Vanuatu a study in ecological economics /

Tacconi, Luca. January 1995 (has links)
Thesis (Ph. D.)--University of New South Wales, 1995. / Includes bibliographical references (leaves 371-411).
45

Sistemas agroflorestais para recuperação de matas ciliares em Piracicaba, SP. / Agroforestry systems for restoration of riparian forests in Piracicaba, SP.

Patricia Pereira Vaz da Silva 09 April 2002 (has links)
A necessidade de recuperação de áreas ciliares degradadas tem subsídio na legislação, porém, o uso de sistemas agroflorestais para esse fim não é permitido. O objetivo desse trabalho é comparar a capacidade de recuperação de dois sistemas agroflorestais e de um plantio florestal com espécies arbóreas nativas, também avaliando as diferenças de custos de implantação e manejo. A pesquisa foi realizada no Estado de São Paulo, município de Piracicaba, às margens do Rio Corumbataí, na propriedade da Usina Costa Pinto, onde o cultivo de cana-de-açúcar ocupa a maior parte do uso do solo. Os tratamentos foram: (1) testemunha; (2) sistema florestal, com 10 espécies arbóreas nativas; (3) sistema agroflorestal simples, com as mesmas arbóreas nativas, guandu e feijão-de-porco como adubo verde; (4) sistema agroflorestal complexo, com diversas espécies frutíferas, girassol e capim napier, além das mesmas arbóreas nativas e das duas leguminosas. Os fatores mensurados foram: altura e diâmetro à altura do colo das arbóreas nativas, custos, liberação de CO2 do solo, biomassa microbiana e fertilidade do solo. O SAF simples apresentou as maiores alturas médias, com um aumento de 36% em relação ao sistema florestal. O SAF complexo apresentou resultados intermediários, com altura média 10% superior à do sistema florestal. Separando as espécies em pioneiras e não pioneiras, as primeiras não apresentaram diferença entre os tratamentos, tendo as não pioneiras crescido cerca de 35% melhor no SAF simples. Supõe-se que as leguminosas tenham cumprido a função de pioneiras, melhorando o ambiente e propiciando o melhor crescimento das não pioneiras. A média do diâmetro de todas as espécies para cada tratamento apresentou diferença entre o SAF simples (51% maior) e o SAF complexo, sendo ambos semelhantes ao sistema florestal, que foi intermediário. Entre pioneiras e não pioneiras, as diferenças foram semelhantes, sendo o SAF simples 67% superior ao SAF complexo, entre as pioneiras, e 33% superior entre as não pioneiras. As análises de solo, tanto de biomassa microbiana, liberação de CO2 ou de fertilidade, não mostraram diferenças entre os tratamentos. Numa estimativa com base nas modificações sugeridas a partir dos dados do experimento, o SAF simples pode ter um custo 16% inferior ao do sistema florestal, principalmente devido à redução da necessidade de manutenção do sistema. O SAF complexo apresentou o maior custo dos três tratamentos, pois, além da grande demanda de mão-de-obra, o sistema encontra-se fora dos padrões legais para venda de sementes. O estudo da heterogeneidade do ambiente reforça a necessidade do uso de métodos de implantação e de manejos diferentes para cada situação encontrada e permitiu inter-relacionar os blocos quanto à degradação, com base nas médias dos blocos, para todos os parâmetros avaliados. Seguindo critérios semelhantes, as espécies arbóreas nativas também foram ordenadas segundo a sucessão, de acordo com a teoria de Götsch: Sangra d’água, Embaúba, Cordia, Mutambo, Pau Viola, Tamboril, Trema, Canafístula, Aroeira, Canelinha. Em condições de grande fragmentação da matriz florestal e forte domínio de gramíneas, o uso de sistemas agroflorestais na recuperação de matas ciliares pode trazer efeitos positivos ao crescimento das árvores nativas e redução no custo de implantação. / Riparian forest is the vegetation that borders rivers, ponds and lakes, and although it is protected by law, agricultural systems are widely used in these areas. Restoration of deforested riparian zones is requested by law, but agroforestry systems are not accepted for this purpose. The objective of this research was to compare the restoration success and the costs of three kinds of restoration management systems: two agroforestry systems and one forestry system, intending to give basis for changes in public policies. This research was carried out in São Paulo State, Piracicaba County, in the Corumbataí River watershed, in the farm of Usina Costa Pinto, where sugar cane fills most of the lanscape. The treatments were: (1) control; (2) forestry system, with 10 native tree species; (3) agroforestry system 1, where two herbaceous/shrub legume species were included in addition to trees; (4) agroforestry system 2, were 10 edible fruit species, sunflower and napier grass were added. Management was evaluated by measuring height and diameter of the native tree species, soil respiration, microbial biomass and soil fertility. Comparing the mean height of all species, agroforestry system 1 showed the best results, which was 36% better than the forestry system. Agroforestry system 2 showed intermediate results: mean height was 10% higher than the one achieved in forestry system. When the species were grouped according to ecological succession, pioneers didn’t present any difference between treatments, but not-pioneers grew 35% better in agroforestry system 1. Probably, legume plants played the role of pioneers, improving the environment and supporting a better development of the non-pioneers. The mean diameter at ground level of all the species showed differences between agroforestry system 1 (51% better) and agroforestry system 2, but both were not different from the forestry system, which had intermediate results. There were similar differences when the species were grouped in pioneers and non-pioneers. For pioneers, agroforestry system 1 was 67% better than agroforestry system 2 and, for non pioneers, this difference was of 33%. There were no differences among treatments in soil fertility, microbial biomass and soil respiration. Estimating the costs, on the basis of modifications suggested after data analysis, agroforestry systems 1 may cost 16% less than forestry system, due to less necessity of interventions for weeds control. Agroforestry system 2 had the highest cost because it demanded much more work than other treatments and this system, like agroforestry system 1, is out of legal standard for seed production. Studies on the environment heterogeneity allowed to rank blocks, based on the block means of all the measured parameters. Based on the same principles, the native tree species were also ranked according to Götsch succession theory: Croton urucurana, Cecropia pachystachya, Cordia superba, Guazuma ulmifolia, Cytharexyllum myrianthum, Enterolobium contortisiliquum, Trema micrantha, Peltophorum dubium, Schinus terebinthifolius, Nectandra megapotamica. In conditions of high fragmentation of natural forests and high density of weeds, agroforestry systems may cause positive effects in riparian forests restoration, favoring better growing of native trees and lower costs of restoration.
46

Relationships between motivation and psychological distance in a forest recreation environment

Hoar, Alexander R. 12 June 2010 (has links)
The purpose of this study was to field test a portion of the recreation quality theory: a conceptual framework which seeks to provide insight into the behavior of outdoor recreationists. Specifically, the inverse relationship of two variables which may affect the quality of outdoor recreation was examined. These were the force of motivation and the psychological distance to the user's destination in a recreation environment. Time spent hiking to the destination was considered a function of force, and physical distance was considered a function of the psychological distance to the destination. It was hypothesized that people who were able to accurately determine the distance remaining to the destination, as they were hiking along the trail, would arrive sooner than those who could not accurately determine the distance remaining to the destination. A map was used to provide users with information about· distances. The hiking times for 109 visitor groups at the Cascades Nature Trail in the Jefferson National Forest, Virginia were unobtrusively recorded between September 26 and November 7, 1976. Differences between the hiking times of groups were analyzed by means of Wilcoxon's Rank Sum Test, the Ansari-Bradley Dispersion Test, and the Moses Dispersion Test. The effects of changing environmental conditions were assessed by means of the Kruskal-Wallis Test for Multiple Comparisons, as well as by Wilcoxon's Rank Sum Test. This study provided evidence that supports the hypothesis proposed in the recreation quality theory, that an inverse relationship exists between the force of motivation and the psychological distance to a goal in a forested recreation environment. / Master of Science
47

Developing a spatial decision support system for timber sale planning on a national forest

Kenney, David Peter 30 December 2008 (has links)
Resource planning on National Forests has become a complex and time consuming process. On the Jefferson National Forest (JNF), "Opportunity Area Analysis" (OAA) is used to implement the resource use mandates of the JNF Land and Resource Management Plan. Timber sale planning is an important component of the OAA process that requires the evaluation and analysis of large amounts of site-specific data and complex spatial relationships. Since geographic information systems (GIS) can manage spatial information efficiently, a prototype spatial decision support system (SDSS) was developed that integrates the data, GIS analysis routines, graphical map and tabular displays, and user interface utilities to interactively support the timber sale planning process. The objectives of this research are: (1) to model the timber sale planning decision process, (2) develop the SDSS model, (3) demonstrate the use of SDSS on a case study area in the JNF, and (4) compare the SDSS approach to current manual methods for timber sale planning. The SDSS model is structured to assist the planner in four areas: (1) identification of suitable stands for timber sale planning in the opportunity area, (2) evaluation and analysis of environmental and social objectives specific to each candidate stand, (3) economic analysis of the candidate stands, and (4) development of timber sale alternatives for a short term planning period. When compared to the manual methods currently used, the SDSS approach to timber sale planning provides faster access to current resource information, helps define and structure the timber sale planning process,a1lows flexibility in plan development, and assembles information for map production and report generation. Recommendations for future SDSS research are also discussed. / Master of Science
48

Case studies of the role of nonprofit volunteer organizations in forest recreation and park management

Jacobi, Charles D. January 1982 (has links)
Nonprofit, volunteer organizations assist government agencies in managing the recreational resources of public lands in many parts of the Eastern United States. With a depressed economy, the role these organizations take can be particularly important in the continuing provision of quality outdoor recreation experiences. This study examines the contributions of five nonprofit groups in the East, the Appalachian Mountain Club, Green Mountain Club, Adirondack Mountain Club, Potomac Appalachian Trail Club, and the Appalachian Trail Conference, and their cooperative relationships with, respectively, the White Mountain National Forest, Green Mountain National Forest, New York State Department of Environmental Conservation, Shenandoah National Park, and the Appalachian Trail Project Office (National Park Service). Interviews with key members of the agencies and the nonprofit groups provided most of the information on club activities and the advantages, problems, and constraints of cooperative relationships from the point of view of each party. Legislation and policy affecting nonprofit involvement on public lands is discussed as well as the prospects of future involvement of these groups. / Master of Science
49

Large-scale analysis of sustainable forest management indicators assessments of air pollution, forest disturbance, and biodiviersity [sic] /

Coulston, John Wesley, Riitters, Kurt. Smith, Gretchen Cole. January 2004 (has links)
Thesis (Ph. D.)--North Carolina State University, 2004. / Title from PDF title page (viewed Mar. 27, 2005). Includes vita. Includes bibliographical references.
50

Does institutional capacity matter? a case study of the Zambian Forestry Department /

Makano, Rosemary Fumpa. January 2008 (has links)
Title from title page of PDF (University of Missouri--St. Louis, viewed February 24, 2010). Includes bibliographical references (p. 328-345).

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