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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.
101

Composição e estrutura da comunidade de peixes recifais em relação a quatro variáveis ambientais no Parque Estadual Marinho da Laje de Santos, Estado de São Paulo / Composition and structure of reef fish community structure in relation to four environmental variables in the Marine State Park of slab Santos, Sao Paulo State

Luiz Junior, Osmar José 05 June 2009 (has links)
Orientadores: Ivan Sazima, Carlos Eduardo Leite Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-18T21:56:33Z (GMT). No. of bitstreams: 1 LuizJunior_OsmarJose_M.pdf: 5451042 bytes, checksum: 29619a9d7010f69a9bd352d2cbc12792 (MD5) Previous issue date: 2009 / Resumo: O Parque Estadual Marinho da Laje de Santos localiza-se na costa sudeste do Brasil a 36 km da cidade de Santos, Estado de São Paulo. O Parque consiste uma pequena ilha (Laje de Santos) com vários parcéis rochosos submersos. O substrato é composto por rochas graníticas cobertas por algas e várias espécies de invertebrados. Desde 1993, foi declarada como área de proteção marinha e desde então o local é de particular interesse, pois é a única área totalmente fechada para a pesca na região mais povoada e desenvolvida do país. Uma lista com 196 espécies de peixes recifais registradas é apresentada para o Parque Estadual Marinho da Laje de Santos. A maioria das espécies tem ocorrência comum a todo o Atlântico Ocidental tropical ou ocorre nos dois lados do Oceano Atlântico. Uma parte menor das espécies tem distribuição em comum com os recifes rochosos temperados da Patagônia ou é endêmica ao Sudeste do Brasil. Moringua edwardsi, Antennarius multiocellatus, Scorpaena dispar, Aulostomus strigosus, Lutjanus buccanella, Mulloidichthys martinicus and Halichoeres penrosei tem aqui seu limite merional de distribuição estendido ao Estado de São Paulo. Há uma clara diferença na contribuição dos fatores abióticos para a estruturação da comunidade de peixes recifais. A profundidade foi o fator que mais influenciou a riqueza de espécies e abundância de indivíduos, apresentação uma clara distinção ambiental entre raso e fundo, com um decréscimo da riqueza e abundância conforme o aumento da profundidade. A complexidade do habitat também foi um fator de influência na comunidade, sendo a riqueza e abundância correlacionada com maior complexidade. Entretanto, esta relação só foi significativa na menor profundidade avaliada. A exposição às ondas não se correlacionou com nenhum dos descritores da comunidade utilizados neste estudo. Aparentemente os efeitos do hidrodinamismo em recifes rochosos se manifesta em escalas espaciais maiores entre a costa e ilhas com diferentes distâncias da costa. Espécies de diferentes categorias tróficas não respondem da mesma maneira a estes fatores. Herbívoros vagueadores são afetados pela profundidade, herbívoros territoriais pela complexidade e pela exposição a ondas, enquanto que planctívoros são afetados pela complexidade do habitat e em menor extensão pela profundidade. Análises de espécies filogeneticamente relacionadas sugerem que ocorre partição de nicho, aparentemente mediada pela capacidade de natação em resposta ao grande dinamismo que ocorre nas zonas rasas. A água fria oriunda de eventos de reesurgência foi um fator de redução da abundância e número de espécies capazes de extender sua distribuição batimétrica para as zonas mais fundas, desencadeando respostas comportamentais específicas em algumas espécies como a formação de densos cardumes na camada superficial durante os eventos de ressurgência. Herbívoros vagueadores e onívoros foram os grupos tróficos que foram particularmente afetados pela intrusão de água fria. Em geral, espécies com alta capacidade de mobilidade evitam a camada de água fria abaixo da termoclina durante o verão e espécies de pequena capacidade de mobilidade ou extremamente territoriais não alteram sua abundância em resposta estes eventos / Abstract: The Laje de Santos State Marine Park is located on the southeastern coast of Brazil, 36 km off the city of Santos, São Paulo State. It consists of an uninhabited islet and several sparse rocky reefs with extensive sand bottoms in between. The subtidal substrate is composed of granitic boulders of varying sizes and shapes. The rocky substrate is mainly covered with patches of algae and several species of sessile invertebrates. Since 1993 the Laje de Santos Island was declared a protected area. The area is of particular interest as this is the only Marine Protected Area totally closed to fishing in the most populated and developed region of Brazil. A check-list containing 196 species of reef fishes recorded at the Laje de Santos Marine State Park is presented. Most of them occur along the tropical western Atlantic or occur on both sides of the Atlantic Ocean. A minor part ranges to the temperate rocky reefs of Patagonia or are endemics to southeastern Brazil. Moringua edwardsi, Antennarius multiocellatus, Scorpaena dispar, Aulostomus strigosus, Lutjanus buccanella, Mulloidichthys martinicus and Halichoeres penrosei have here their ranges extended southward to the São Paulo coast. There is a clear difference among the contributions of each abiotic factors analyzed in the reef fish community structure. Depth was the most influent factor on species richness and abundance, presenting a clear distinction between shallow and deep zones with a decrease of both factors with depth increase. Habitat complexity also had an influence in the community, being species richness and abundance correlated with higher complexity. However, this relationship was significant on the shallower evaluated depth only. Exposition to wave surge does not correlate with any of the community descriptors used in this study. Apparently, hydrodynamics effects on rocky reefs manifest only at larger spatial scales like between the shore and islands. Species on different trophic categories do not respond the same way to these factors. Vagrant herbivores are affected by depth; territorial herbivores by habitat complexity and marginally by exposition, and planktivorous are affected mostly by habitat complexity and in less extension by depth. Analyses of phylogenetically related species suggest that niche partitioning occur, apparently mediated by swimming capacity in response to higher hydrodynamic forces occurring in shallow water. Cold water derived from upwelling events was a further factor reducing species richness and abundance, triggering specific behavioral responses in some species such as the formation of tight packed schools in the surface layer during upwelling. Vagrant herbivores and omnivores were the trophic groups most affected by upwelling. In general, species with high mobility capacity avoid the cold-water layer below the thermocline during summer and species with limited mobility capacity do not change their abundance is response to these events / Mestrado / Ecologia / Mestre em Ecologia
102

Use of Satellite Imagery and GIS to Model Brood-Rearing Habitat for Rio Grande Wild Turkey Populations Occurring in the Western Cross Timbers Region of Texas

Miller, Christopher J. 08 1900 (has links)
Remote sensing and GIS have become standard tools for evaluating spatial components of wildlife habitats. These techniques were implemented to evaluate Rio Grande wild turkey (Meleagris gallopavo) poult-rearing habitat in the Western Cross Timbers region of Texas. Texas Parks and Wildlife (TPWD) random roving turkey counts for 1987-1989 and 1998-2000 were selected, indicating locations where hens with poults were observed. Satellite imagery from 1988 and 1999 was classified and then processed with Patch Analyst. To add robustness, stream, road and census population densities were also evaluated for each turkey location. Analysis of the 1988 canopy cover image, comparing observed locations with randomly-selected habitat cells (N = 20) indicated significant differences (p <.05) for patch edge variables. Mean patch edge was significantly greater for habitat locations where hens with poults were observed than for those selected at random. Spatial data for 1999 did not indicate a significant difference (p < .05) between sampling groups (observed vs. random, N = 30). Significant differences (p <.05) did occur for turkey locations observed in both 1988 and 1999 (N = 7). This demonstrates the adaptability of wild turkey hens, as habitats change over time, hens continued to visit the same locations even though the habitat had significantly changed for select spatial variables.
103

Use of geographic information systems and infrared-triggered cameras to assess white-tailed deer (Odocoileus virginianus) habitat in Denton County, Texas.

Sallee, David R. 08 1900 (has links)
This study utilized geographic information systems, remote sensing, and infrared-triggered cameras to assess white-tailed deer habitat in Denton County, Texas. Denton County is experiencing tremendous growth in both population and development. Despite their presence here historically, white-tailed deer were all but extirpated by the beginning of the 20th century, and there are no data available which support their presence in Denton County again until the 1980's. This study attempts to equate the increase in white-tailed deer population to Denton County's transformation from an agricultural to an urban economy and lifestyle. Eighteen sites were chosen throughout the county to research the following metrics: geology, soils, landcover, landscape ecology, streams, shorelines, land use, population, roads, structures, and census methods.
104

Determining the Suitability of Functional Landscapes and Wildlife Corridors Utilizing Conservation GIS Methods in Denton County, Texas.

Sales, Joshua 08 1900 (has links)
Denton County's unique cultural and natural landscape has undergone dramatic transformations during the past two centuries due to agricultural, urban and suburban processes which accelerated the loss and removal of native habitat and wildlife. This research sought out to identify the remaining natural areas which retain their natural features and support wildlife. Research methodology included fundamental principles of Conservation Planning, Geographical Information Systems, and Habitat Evaluation Procedures for identifying remnant functional landscapes and wildlife corridors. The final results suggest that Denton County's rural landscape retains the functional properties and elements suitable for habitat conservation and wildlife corridors, while also pointing to the fundamental obstacles to conservation posed by continued growth and private landownership.
105

A Habitat Evaluation and Management Plan for a Riparian Ecosystem

Wilkinson, Robert N. 05 1900 (has links)
Ecological research involving habitat studies was conducted on the Elm Fork of the Trinity River in Denton County, Texas, from spring 1985 to spring 1986. Habitat Evaluation Procedures and Habitat Suitability Index Models developed by the United States Fish and Wildlife Service were applied to a 1419 hectares study area to determine the quality of habitat for four species: beaver, Castor canadensis, wood duck, Aix sponsa, pileated woodpecker, Dryocopus pileatus, and white crappie, Poxomis annularis. Population estimates were generated. A wildlife management plan was developed for the study area. Habitat Suitability Index Models were found to be overly conservative, underestimating the quality of habitat in areas of ecological transition.
106

Population distribution, habitat selection, and life history of the slough crayfish (Procambarus fallax) in the ridge-slough landscape of the central Everglades

Unknown Date (has links)
Understanding where and why organisms are distributed in the environment are central themes in ecology. Animals live in environments in which they are subject to competing demands, such as the need to forage, to find mates, to reproduce, and to avoid predation. Optimal habitats for these various activities are usually distributed heterogeneously in the landscape and may vary both spatially and temporally, causing animals to adjust their locations in space and time to balance these conflicting demands. In this dissertation, I outline three studies of Procambarus fallax in the ridge-slough landscape of Water conservation Area 3A (WCS-3A). The first section outlines an observational sampling study of crayfish population distribution in a four hectare plot, where I statistically model the density distribution at two spatial scales. ... Secondly, I use radio telemetry to study individual adult crayfish movements at two study sites and evaluate habitat selection using Resource Selection Functions. In the third section, I test the habitat selection theory, ideal free distribution, by assessing performance measures (growth and mortality) of crayfish in the two major vegetation types in a late wet season (November 2007) and early wet season (August 2009). / by Craig van der Heiden. / Thesis (Ph.D.)--Florida Atlantic University, 2012. / Includes bibliographical references at the end of each chapter. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
107

The avian community characteristics of constructed treatment wetlands of South Florida

Unknown Date (has links)
This study compared the avian communities of treatment wetlands in South Florida called Stormwater Treatment Wetlands (STAs) to those in natural marshes and crop lands, and examined factors that influenced the size and structure of the avian communities within the STAs. The STAs contained a more abundant, rich and distinct avian community compared to reference land types. The STAs were dominated by wintering waterfowl, and therefore community patterns fluctuated more seasonally other land types. Within the STAs, density and richness in the fall and winter were much greater in the submerged aquatic vegetation than in the mixed emergent vegetation when waterfowl were present. The STAs maintain two vegetation treatments which enhanced their biodiversity value by supporting distinct avian communities with different migratory strategies This suggests the increase in treatment wetlands could partially offset the loss of natural wetlands, but avian communities in treatment wetlands are not surrogates for natural wetlands. / by Tyler J. Beck. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
108

Effects of man on the vegetation in the national parks of South Australia

Mattiske, Elizabeth M. January 1975 (has links) (PDF)
Volume 2 consists almost entirely of maps. Includes index of plant species. Bibliography: p. 227-242 (v.1) Floristic and structural changes in native vegetation resulting from man's influence are examined in detail in 5 South Australian parks. The results permit the clear delineation and segregation of those patterns determined by man's activities, from those induced by soil and topographic features.
109

Spotted owls, great horned owls, and forest fragmentation in the central Oregon Cascades

Johnson, David Harold, 1956- 12 June 1992 (has links)
Graduation date: 1993
110

Factors que afecten l’èxit d’expansió de poblacions d’aus en medis transformats per l’home: l’arpella "Circus aeruginosus" a la Vall de l’Ebre Factors affecting expansion success of bird populations in human-transformed environments: the marsh harrier Circus aeruginosus in the Ebro Valley

Cardador Bergua, Laura 07 October 2011 (has links)
Change in species geographic ranges is a natural phenomenon, but the rate and magnitude of such change has significantly increased due to anthropogenic causes. The rate at which a population spreads/contracts through space is a function of the rates of population growth and dispersal, coupled with density-dependence. Human-induced environmental changes can lead to variation in density-independent components of local birth or death rates through deterministic process (e.g. impoverishment/increase of habitat and food resources), thus pushing populations toward positive/negative growth. Moreover, spatial range constraints, such as dispersal, and density-dependence may also limit population growth and range expansion, beyond environmental characteristics. The main goal of this thesis is to explore the role played by ecological factors such as habitat and food availability, spatial range constraints and density-dependence in the expansion of a species through human-transformed environments. For this purpose, I use as a study model an expanding population of the marsh harrier living in an agricultural landscape of the Ebro Valley (northeastern peninsular Spain). Results obtained in this thesis suggest that environmental factors, sociability, dispersal constraints and density-dependent mechanisms may play an important role in the distribution of a species. Marsh harrier breeding numbers had been greatly reduced in previous decades (1960-1980) mainly due to organochlorine pesticides, drainage of wetlands and direct persecution. Thus, at least part of their increase in recent decades may represent population recovery following reductions in organochlorine use and direct persecution. However, the species may also have benefited from the spread of human-made structures such as artificial ponds and reservoirs related to agricultural intensification, for breeding and from their surrounding herbaceous crops for hunting. At a local scale, individual variation in density-dependence for productivity and settlement patterns may have favoured dispersal of some individuals to new empty habitat patches, while others aggregated around traditional areas. However, at a large scale (i.e., across peninsular Spain), the breeding population of marsh harriers seems to be spatially constricted beyond environmental variables. This result indicates that potential habitat for marsh harriers still exists for further expansions in the Iberian Peninsula (at least at the spatial resolution of our analyses, which does not allow us to consider smaller scale processes that may restrict the species distribution such as local food abundances or pesticides). Potential consequences of this expansion for other species should be considered in order to properly conserve biodiversity in a world of change. / En aquesta tesi s’analitza el paper que desenvolupen factors ecològics com l’hàbitat i la disponibilitat d’aliments, les limitacions espacials i la denso-dependència en l’expansió d’una espècie en ambients transformats per l’home. S’utilitza com a model d’estudi l’arpella Circus aeruginosus en una zona agrícola de la Península Ibèrica, a la part oriental de la Vall de l’Ebre. Els resultats d’aquesta tesi indiquen que tant els factors ambientals, de sociabilitat, les limitacions dispersives i els mecanismes de denso-depèndecia poden jugar un paper important en la distribució d’una espècie. La població d’arpella s’havia reduït en dècades anteriors (1960-0980) degut principalment a l’assecament i contaminació de les zones humides on criava, a l’ús de pesticides i a la persecució directa per part de l’home. Si bé, part de l’augment que la població ha experimentat en els darrers anys podria ser degut a la recuperació de la seva població després de la reducció en l’ús d’organoclorats i en la seva persecució per part d l’home, l’espècie també s’hauria beneficiat en els darrers anys de l’increment d’estructures artificials, com embassaments i basses de reg artificials relacionades amb l’agricultura, e l’espècie utilitza per nidificar i dels cultius herbacis del voltant per caçar. A escala local, la variació individual en els efectes de la denso-dependència en la productivitat i patrons d’assentament, podrien haver afavorit la dispersió d’alguns individus a noves localitats buides, mentre altres individus amb una resposta diferent a la densitat s’agregaven al voltant de zones ja ocupades. A escala de la Península Ibèrica, l’àrea de distribució de l’arpella encara es veuria limitada, per factors espacials diferents al clima i al tipus d’hàbitat, indicant que encara hi hauria hàbitat potencial per a l’espècie (com a mínim a la resolució espacial de les nostres anàlisi, que no permeten considerar processos a escala local). Les possibles conseqüències de l’expansió d’aquesta i altres espècies haurien de ser considerades per tal de conservar adequadament la biodiversitat en l’actual escenari de canvi global.

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