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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.
21

Avaliação do efeito da face de exposição solar sobre o crescimento de plantios comerciais de Eucalyptus sp na região sudoeste do estado de São Paulo / Evaluation of the effect of the aspect on the growth of commercial Eucalyptus sp plantations in the southwest region of the state of São Paulo

Gonçalves, Débora Romano Camilo 05 December 2014 (has links)
As regiões de cultivo de eucalipto apresentam um grande número de variações ambientais em nível microrregional, como pode ser facilmente constatado quando se observam as diferenças expressivas entre as produtividades florestais de cada área. No entanto, para se avaliar um ambiente, é necessário identificar segmentos específicos dentro de uma paisagem, tratando-se de uma propriedade florestal e, dentro desse estudo, buscar a compreensão das interações que aí se processam. Este trabalho contribui para entender o efeito da face de exposição solar no crescimento de plantios comerciais de Eucalyptus. A proposta metodológica apresentada leva em consideração o conhecimento do meio físico - tendo como base a fisiografia para distinção das faces de exposição solar- além disso, a interação dos fatores fisiográficos com os fatores biológicos são discutidos para subsidiar a tomada de decisão. A acentuada interação genótipo x ambiente presente em muitas culturas faz com que estudos de adaptabilidade a ambientes específicos sejam parte integrante dos programas de pesquisa florestal. A resposta diferenciada dos genótipos a ambientes favoráveis e desfavoráveis pode auxiliar o gestor florestal na alocação assertiva dos materiais genéticos para maximizar a produtividade. O escaneamento a laser aerotransportado, ferramenta de uso precoce no Brasil, é um sensor óptico ativo que mede a distância até os objetos-alvo e foi utilizado para a obtenção da altura das árvores. A área de estudo está localizada na região sudoeste do estado de São Paulo. Dentre as métricas disponíveis do processamento utilizou o percentil 90 de altura para estimar a altura de plantios comerciais homogêneos de Eucalyptus. Elaborou-se a análise de variância considerando um delineamento fatorial contemplando a face de exposição solar (norte e sul) e o material genético (clones comerciais), além da interação entre ambos para observar o efeito da face no crescimento em altura do povoamento. Para florestas abaixo de quatro anos de idade observou-se que os plantios de face sul cresceram menos que os da face norte. Para florestas acima de 5 anos essa diferença entre face continua, contudo, quando concluído o desdobramento da interação fatorial observou-se que os materiais genéticos plantados em face norte não diferem entre si, mas a diferença se mantém para florestas em face sul. / The eucalyptus cultivation regions boast a large number of environmental variables in micro-regional level, as can easily be seen when studying the expressive differences between the productivity of each forest area. To evaluate an environment, however, it is necessary to identify specific segments within a landscape with regards to a forest property and within that landscape study to seek the understanding of the interactions that takes place in the process. This work contributes to a better understanding of the effect of the aspect on growth in commercial plantations of Eucalyptus. The methodological approach presented in this work takes into account the knowledge of the physical environment, based on physiography, for distinction of aspect on environments, in addition to showing the interaction of physiographic factors with biological factors to support the decision-making process. The sharp interaction genotype x environment present in many cultures leads to studies of adaptability to specific environments to become integral parts of forestry research programs. The differentiated response of genotypes to favorable and unfavorable environments can assist forest managers in the allocation of assertive genetic materials to maximize productivity. The airborne laser scanning, which is an early tool used in Brazil, is an active optical sensor that measures the distance to the target objects, was used to obtain the height of the trees. The study area is located in the southwestern region of the State of São Paulo in Brazil. Among the available processing metrics, it was used 90 percentiles in height to estimate the height of homogeneous commercial plantations of Eucalyptus. A variance analysis was devised considering a factorial design contemplating the aspect (North and South) and genetic material (commercial clones), besides the interaction between both to observe the effect of the exposure on the height growth of the settlement. To forests below four years of age, it was observed that the plantations of the South exposure grow less than the north exposure. For forests above five years, this difference between aspect continues, however, when the deployment of factorial interactions is done, it\'s observed that the genetic materials planted in the north exposure do not differ with each other, but the difference stands within forests in the South exposure.
22

Acidic deposition effects on above- and belowground wood biomass and nutrient status in a young hardwood forest

Johnson, Brittany Anne. January 2009 (has links)
Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains vii, 119 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
23

Crown structure, stand dynamics, and production ecology of two species mixtures in the central Oregon Cascades /

Garber, Sean M. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2003. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
24

Moose population density and habitat productivity as drivers of ecosystem processes in northern boreal forests /

Persson, Inga-Lill. January 2003 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2003. / Appendix consists of reproductions of six papers and manuscripts, five co-authored with others. Thesis documentation sheet inserted. Includes bibliographical references. Issued also electronically via World Wide Web in PDF format; online version lacks appendix of papers.
25

Classification of mid-seral black spruce ecosystems of northern British Columbia. Full report.

Krestov, Pavel, Klinka, Karel, Chourmouzis, Christine, Kayahara, Gordon J. 03 1900 (has links)
This full report presents a classification of mid-seral black spruce ecosystems in the Boreal White and Black Spruce (BWBS) and Sub-boreal Spruce (SBS) zones of British Columbia. The classification is based on a total of 122 plots sampled during the summers of 1997 and 1998. We used multivariate and tabular methods to synthesize and classify ecosystems according to the Braun-Blanquet approach and the methods of biogeoclimatic ecosystem classification. The black spruce ecosystems were classified into 8 vegetation units (associations or subassociations) and the same number of site associations. We describe vegetation and environmental features of these vegetation and site units. Vegetation and environmental tables for individual plots are given in Appendices. In addition, we also present the relationships between site index of black spruce and direct and indirect measures of site quality.
26

Classification of trembling aspen ecosystems in British Columbia

Klinka, Karel January 2001 (has links)
This pamphlet provides a summary of a fuller report issued under the same title.
27

Classification of trembling aspen ecosystems in British Columbia. Full report.

Krestov, Pavel, Klinka, Karel, Chourmouzis, Christine, Hanel, Claudia 03 1900 (has links)
This full report presents the first approximation of vegetation classification of trembling aspen ecosystems in interior British Columbia. The classification is based on a total of 186 plots sampled during the summers of 1995, 1997 and 1998. We used multivariate and tabular methods to synthesize and classify ecosystems according to the Braun-Blanquet approach and the methods of biogeoclimatic ecosystem classification. The aspen ecosystems were classified into 15 basic vegetation units (associations or subassociations) that were grouped into four alliances. Communities of the Populus tremuloides – Mertensia paniculata, and Populus tremuloides – Elymus innovatus alliances were aligned with the boreal Picea glauca & mariana order and were distributed predominantly in the Boreal White and Black Spruce zone; communities of the Populus tremuloides – Thalictrum occidentale alliance were also aligned with the same order, but were distributed predominantly in the Sub-Boreal Spruce zone; communities of the Populus tremuloides – Symphoricarpos albus alliance were aligned with the wetter cool temperate Tsuga heterophylla order and the drier cool temperate Pseudotsuga menziesii order and were distributed in the Sub-boreal Spruce, Interior Western Hemlock, Montane Spruce, and Interior Douglas-fir zones. We describe the vegatation and environmental features of these units and present vegetation and environmental tables for individual plots and units.
28

Classification of mid-seral black spruce ecosystems in northern British Columbia

Klinka, Karel January 2001 (has links)
This pamphlet provides a summary of a fuller report issued under the title: Classification of mid-seral black spruce ecosystems of northern British Columbia
29

A comparison of Grand fir and Douglas-fir growth performance in the Elk River Tree Farm

Klinka, Karel, Bernardy, Paul, Chourmouzis, Christine January 1998 (has links)
The superior growth of Grand fir (Abies grandis) compared to Douglas-fir (Pseudostuga menziesii) on suitable coastal sites has previously been recognized on the basis of qualitative observations with little empirical evidence. For example, D.E. McMullan (1977, pers. comm.) reported 18% higher volume for a grand fir tree of the same height and age as a 108-year old Douglas-fir plus tree (No. 622) This study was undertaken by Bernardy (1988) to examine possible differences in the growth of grand fir and Douglas-fir growing in a mixed 40-year-old plantation of unknown origin. Trends in height, diameter and annual volume increment between the two species over time were examined. Expected growth performance (i.e. volume and form) of each species was inferred from trends identified at time of sampling.
30

Relationship of site index to estimates of soil moisture and nutrients for western redcedar in south coastal British Columbia

Klinka, Karel, Kayahara, Gordon J., Chourmouzis, Christine January 1997 (has links)
Where timber production is the primary management objective, knowledge of the relationship between the potential productivity of candidate tree species and levels of light, heat, nutrient, moisture and aeration is necessary for species- and site-specific decision making. For example, foresters need to decide which tree species to regenerate on a particular harvested area to obtain maximum sustainable productivity. Similarily, when considering the application of silvicultural treatments such as spacing or fertilizing, foresters need to determine whether the potential productivity of a particular site warrants the cost of the treatment. We used the site index (height of dominant trees at breast height age) of western redcedar (Thuja plicata Donn. ex D. Don.) as a measure of productivity, and described the pattern of mean site index in relation to field identified soil moisure and soil nutrient regimes.

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