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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.
81

Assessment of aquatic invertebrate communities of tributaries of the Buffalo River, Arkansas, and evaluation of indices of community integrity /

Mixon-Hinsey, Janice Arlene, January 1900 (has links)
Thesis (M.S.)--Missouri State University, 2008. / "December 2008." Includes bibliographical references (leaves 63-74). Also available online.
82

A comparision study of migratory raptor distribution and habitat use at the Cape May peninsula stopover

Frank, Cristina A. January 2007 (has links)
Thesis (M.S.)--Rutgers University, 2007. / "Graduate Program in Ecology and Evolution." Includes bibliographical references (p. 62-64).
83

Modelling fisher (martes pennanti) habitat associations in Nova Scotia /

Potter, Derek Noel. January 1900 (has links) (PDF)
Thesis (M.Sc.)--Acadia University, 2002. / Includes bibliographical references ( leaves 67-77). Also available on the Internet via the World Wide Web.
84

Cerulean warbler (Dendroica cerulea) breeding ecology and habitat selection, initial response to forest management, and association with anthropogenic disturbances in the Cumberland Mountains of Tennessee

Beachy, Tiffany-Ahren, January 2008 (has links) (PDF)
Thesis (M.S.)--University of Tennessee, Knoxville, 2008. / Title from title page screen (viewed on Sept. 23, 2009). Thesis advisor: David A. Buehler. Vita. Includes bibliographical references.
85

Distribution and habitat use by juvenile Atlantic salmon (Salmo salar) at multiple spatial scales, and implications for habitat modelling and fish-habitat management /

Bult, Tammo Peter, January 1999 (has links)
Thesis (Ph.D.)--Memorial University of Newfoundland, 1999. / Bibliography: leaves 212-224.
86

Influence of habitat complexity in structuring species-specific interactions and trophic linkages on oyster reefs of southeastern North Carolina /

Sonnier, Joseph M. January 2006 (has links) (PDF)
Thesis (M.S.)--University of North Carolina at Wilmington, 2006. / Includes bibliographical references (leaves: 53-59)
87

Padrões de uso do espaço em multiplas escalas por roedores e marsupiais de Mata Atlantica / Multi-scale patterns of space use by rodents and marsupials in the atlantic forest

Leiner, Natália Oliveira 05 April 2009 (has links)
Orientador: Wesley Rodrigues Silva / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-13T16:39:50Z (GMT). No. of bitstreams: 1 Leiner_NataliaOliveira_D.pdf: 1793051 bytes, checksum: 67b783e1e2d52a03688d55890fd30fc8 (MD5) Previous issue date: 2009 / Resumo: Diversos fatores influenciam os padrões de uso de espaço de pequenos mamíferos, tais como estrutura de hábitat, riscos de predação e período reprodutivo. O objetivo desse estudo foi investigar a influência de tais fatores sobre o uso de espaço de roedores e marsupiais em diferentes escalas. No primeiro capítulo, analisamos a estrutura das comunidades de pequenos mamíferos não-voadores que ocorrem em fragmentos florestais e em áreas em restauração, e investigamos quais componentes do hábitat influenciam a composição de espécies dessas comunidades. De forma geral, os resultados mostraram que a composição de espécies é um reflexo das preferências que as espécies apresentam por determinados componentes do hábitat, de forma que características estruturais da vegetação e sensibilidade das espécies às alterações determinam a estrutura das comunidades de pequenos mamíferos nos hábitats amostrados. No segundo capítulo, testamos a hipótese de que a importância de diferentes fatores na seleção de hábitats por Marmosops incanus e Marmosops paulensis depende da escala de observação, e a hipótese de que o uso de hábitat funciona como um mecanismo para garantir a coexistência dessas duas espécies, de forma que essas espécies devem selecionar diferentes componentes do hábitat e/ou apresentar segregação no uso vertical do espaço. Os resultados demonstraram que ambas as espécies selecionam os fragmentos florestais pela presença de maior complexidade estrutural e sub-bosque denso, variável que também influenciou a distribuição dessas espécies na escala do meso-hábitat. Na escala mais fina, do micro-hábitat, foram detectados padrões contrastantes de seleção para cada espécie. Enquanto M. incanus preferiu locais com maior estruturação vertical entre 0.5 e 1.0 m, M. paulensis não apresentou padrões claros de seleção de hábitat. Esse resultado aponta a influência da escala de observação nos padrões de seleção de hábitat. Apesar das espécies não apresentarem segregação na seleção de componentes do hábitat, houve segregação no uso vertical do espaço e a abundância das espécies foi negativamente correlacionada, apoiando em parte a segunda hipótese. No terceiro capítulo, corroboramos a hipótese de que a cobertura de gramíneas determina o uso de hábitat e os padrões de forrageamento por espécies de roedores. Sugerimos que a seleção por áreas com maior cobertura vegetal está relacionada com a diminuição dos riscos de predação durante o forrageamento. Por fim, no quarto capítulo analisamos a organização espacial de machos e fêmeas de M. paulensis durante o ano. Os resultados indicaram que as fêmeas apresentam uma estratégia territorial que parece estar associada à distribuição e previsibilidade dos recursos alimentares, e não ao período reprodutivo e a presença de filhotes. / Abstract: Several factors may influence habitat selection and spatial organization of small mammals, such as habitat structure, predation risks and reproductive activity. The goal of this study was to evaluate the role of these factors on space use patterns of rodents and marsupials at multiple scales. In the first chapter, we evaluated community structure of non-volant small mammals inhabiting forest fragments and restored sites, and discussed which habitat components influenced species composition of these communities. Our results showed that species composition reflects species habitat selection, in a way that habitat structure and ability to occupy disturbed sites determine species composition and community structure in the sampled habitats. In the second chapter, we evaluated the hypotheses that 1) Marmosops habitat selection is scale dependent and 2) in order to coexist, M. incanus and M. paulensis should partition habitat use, through differential use of habitat components and/or segregation in the use of vertical strata. Both M. incanus and M. paulensis occurred almost exclusively at forest fragments, due to higher structural complexity and the presence of a dense and low understory, which also determined the distribution of these species inside the fragments. At a smaller, mesohabitat scale, both species selected areas providing dense understorey, especially vertical obstruction 0-0.5 m above ground. At a finer, micro-habitat scale, we detected contrasting patterns for each species. At this scale, M. incanus preferred places with higher plant cover and higher vertical obstruction 0.5-1.0 m above ground, while M. paulensis presented no evident pattern of habitat selection. Although our results failed to find selection for different habitat variables between M. incanus and M. paulensis, we found an inverse numerical association between species and segregation in the use of vertical strata, thus partially supporting the second hypothesis. In the third chapter, we confirmed the hypothesis that rodent habitat use and foraging behavior is determined by grass cover. We suggested that small rodents avoid foraging in reduced cover sites due to high perceived predation risks. Finally, the fourth chapter evaluated the spatial organization of M. paulensis males and females. As expected, evidence demonstrated that M. paulensis presents a promiscuous mating system, with females defending territories and males moving between these areas, as a strategy to maximize reproductive success. The occurrence of territoriality in females seems to be determined by the distribution and predictability of food resources, rather than reproductive activity and the presence of young. / Doutorado / Doutor em Ecologia
88

Uso do habitat por morcegos filostomideos em um mosaico florestal na Mata Atlantica do sul da Bahia, Brasil : uma abordagem em duas escalas / Habitat use by phylostomidae bats in a forest mosaic in Southern Bahia, Brazil : an approaching in two scales

Baumgarten, Julio Ernesto 14 August 2018 (has links)
Orientador: Eleonore Zulnara Freire Setz / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-14T15:46:40Z (GMT). No. of bitstreams: 1 Baumgarten_JulioErnesto_D.pdf: 1897672 bytes, checksum: 3d8693a668105a0d846b4f1309afcd25 (MD5) Previous issue date: 2009 / Resumo: As características do habitat são um fator determinante na definição da riqueza e abundância das comunidades. A associação dos organismos com ambientes específicos é determinada pelas demandas e possibilidades de exploração dos recursos de cada espécie. Morcegos da família Phyllostomidae são animais com grande mobilidade que utilizam o vôo através da vegetação para localizar e ter acesso dos seus principais recursos. Os filostomideos formam um grupo de mamíferos fortemente associados às florestas tropicais. A região sul da Bahia representa a maior área contínua com cobertura florestal sob o domínio atlântico que ainda permanece no nordeste brasileiro. Essas florestas remanescentes são, de fato, um mosaico composto por florestas nativas e plantações sombreadas de cacau (Theobroma cacaó), localmente conhecidas como cabrucas. O presente estudo investiga como a fauna de morcegos se distribui neste mosaico complexo em uma paisagem fragmentada da região cacaueira abordando a questão a partir de duas escalas distintas. Em uma paisagem desse mosaico no município de Ilhéus, BA, foi investigado: (1) como a riqueza, abundância, diversidade e composição de espécies de morcegos se comportam na conversão de florestas em cabrucas, (2) como estes parâmetros sofrem influência da distância da cabruca a floresta mais próxima e (3) as alterações destes padrões em cabrucas mais intensamente manejadas, com maior desbaste da cobertura de dossel. Em uma escala menor, foi investigada a importância do arranjo espacial da vegetação do subosque de florestas nativas e cabrucas, em sítios localizados nos municípios de Ilhéus e Una, na estruturação das assembléias de morcegos, considerando-se, principalmente as características morfológicas das espécies presentes. Para tanto foi desenvolvido um método, baseado no uso de fotografias, de onde foram extraídas métricas descritoras da complexidade e grau de obstrução da vegetação presente nos sítios amostrados. As respostas dos morcegos a esses descritores foram comparadas às respostas das assembléias de pequenos mamíferos escansoriais e aves frugívoras de subosque encontradas em estudos anteriores realizados nos mesmos sítios de amostragem. Os resultados corroboram estudos anteriores mostrando que as comunidades de morcegos em cabrucas do sul da Bahia são mais ricas, diversas e abundantes e com composição de espécies diferenciada das florestas, sendo importantes matrizes capazes de manter uma grande quantidade de espécies em uma escala de paisagem. Ao contrário do previsto, o aumento da intensidade de manejo ou da distância da floresta parece não afetar os padrões das variáveis estudadas para a comunidade como um todo ou para as espécies mais abundantes nas florestas. A riqueza de morcegos foi significativa e negativamente correlacionada ao grau de obstrução e à complexidade da vegetação do subosque. Espécies de morcegos com características morfológicas que implicam um vôo energeticamente mais custoso tenderam a não estarem presentes em habitats mais densos e complexos. Morcegos, aves frugívoras e pequenos mamíferos escansoriais respondem de forma diferente aos descritores utilizados, sugerindo formas diferentes de percepção e exploração dos recursos presentes no subosque das florestas da região. / Abstract: Habitat features play a major role influencing species richness and abundance in local communities. The association between a given organism and habitat types is closely determined by the way each species exploits the available resources. Phyllostomide bats comprise a group of species with great mobility, performing highly maneuverable flights trough complex and clutter vegetation in order to detect and access their main food resources. As conspicuous features of the Neotropical forests in general, these bats comprise speciose assemblages along the Atiantic rainforest, a biome drastically reduced, fragmented and disturbed. In the southern region of Bahia state lies the largest areas of the Atlantic forests remaining from the entire northeastern Brazil, although these remnants comprise in fact a mosaic of native forests and shade cacao plantations (Theobroma cacao), locally known as cabrucas. The present study investigates how the Phyllostomidae bats are distributed along this complex forest mosaic, approaching this question in two different spatial scales. At the landscape scale, it was investigated how the richness, abundance, diversity and composition of bat species are influenced by (1) the conversion of native forests into cabrucas; (2) according to the distance of a given cabruca to a native forest remnants and by (3) differences in management intensity among shade plantations, mostly determined by the level of canopy cover left. At a lower spatial scale, the question investigated focused on whether the spatial arrangement of the understory vegetation in a given site could influence the structure of bat assemblages, taking into account morphological features of the species locally present. To accomplish for this goal, a new method was developed to extract a range of metrics needed to describe the complexity and clutter level of the vegetation at each sampling site. The outcomes of the bat assemblages were compared with those achieved for scant small mammals and understory frugivorous bird assemblages sampled along the same sites. Overall, the results corroborate previous studies showing that cabrucas comprise richer, more abundant, more diverse and distinct bat assemblages than those reported for the forest habitats, being important matrix habitats maintaining rich assemblages in a landscape scale. Apparently, neither the distance from a native forest nor the management intensity of a given cabruca seems to influence the bat structure patterns. Nevertheless, at a lower spatial scale, bat species richness was significantly and negatively correlated with the obstruction and complexity level of the understory vegetation. Bat species with morphological features associated with flights that are energetically more costly tended to be absent from more dense and clutter habitats. Bats, birds and small mammals showed different responses relatively to the spatial descriptors applied, probably reflecting differences in the way that each biological group perceive and exploit the understory space and its associated resources. / Doutorado / Doutor em Ecologia
89

An assessment of habitat suitability of the proposed Tyefu community game reserve in Ngqushwa (fomerly Peddie) district, Eastern Cape

Mamfengu, Phozisa Faith January 2007 (has links)
Land use forms such as cultivation and livestock farming have become less productive and unsustainable in the Tyefu communal villages of Ngqushwa (Formerly Peddie) district, Eastern Cape, South Africa. This is manifest in abandoned and severely degraded cultivation fields as well as transformed vegetation, making it difficult to earn a land based livelihood. Against the backdrop of severe land degradation and poverty levels in these communal villages, game farming has been recommended as an ecologically, economically and socially sustainable form of land use. Tyefu Community Reserve is a project, recommended by the Subtropical Thicket Ecosystem Project (STEP) backed by the Department of Environment Affairs and Tourism (DEAT), for hunting and venison selling. The proposed area has been fenced and animals to be stocked in the reserve have been requested on a loan basis. Such an undertaking requires an understanding of the abundance and condition of vegetation, terrain parameters, and an assessment of potential wildlife species, as well as the carrying capacity of the recommended reserve as a habitat. With the aid of orthophoto maps, Subtropical Thicket Ecosystem Planning (STEP) shapefiles, ASTER satellite imagery and a High Resolution Digital Camera Image, vegetation types were mapped and their condition was assessed. A Digital Elevation Model (DEM) of the area was used to extract terrain parameters such as slope and aspect. The carrying capacity of the proposed reserve was determined using a model originally developed by Boshoff et al. (2001) for estimating potential wildlife and abundance. The proposed reserve is predominantly covered by dense thicket as compared to the adjacent Tyefu communal villages where thicket has been severely degraded. The prominent topographic characteristics such as slope reveal an escarpment ringing the proposed reserve with gentle slopes towards the centre. Slope direction has also influenced the distribution of vegetation in the proposed reserve, as the moist south facing slopes tend to have a greater proportion of dense thicket as opposed to the warm north facing slopes. Vegetation types and topography of the reserve can provide suitable habitat to a variety of wildlife species and are likely to influence the distribution of mammals in the proposed reserve. The carrying capacity model developed has been useful in determining potential species that can be supported by the reserve, and estimating their abundance. Given the small size of the proposed community reserve (about 1800ha), it has been recommended that it should be stretched to link up with the existing Great Fish River Game Complex. It will then fit within the framework as envisaged by STEP (2004), in the form of Fish River Biodiversity Initiative, a conservation corridor bordering the Great Fish River.
90

The Vegetation and Habitat Factors of Rockwall County, Texas

Smith, W. Desby January 1940 (has links)
This paper consists of a study of the soils and vegetation found in Rockwall County, Texas. This county is located in the northeastern part of the state. Rockwall County lies in the northeastern part of the Black Waxy Belt of the Coastal Plains province.

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