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1
Diniz, Suzana. "Influência da complexidade arquitetural de ramos vegetativos na riqueza e abundância de aranhas e outros artrópodes". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316023.
Testo completoAbstract (sommario):
Orientadores: João Vasconcellos Neto, Gustavo Quevedo RomeroDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-18T01:27:37Z (GMT). No. of bitstreams: 1 Diniz_Suzana_M.pdf: 61632938 bytes, checksum: 7bcbe079e28a7f57357c4d6ecbb16e88 (MD5) Previous issue date: 2011
Resumo: A estrutura do hábitat tem sido um tema recorrente na literatura, havendo diversos estudos que correlacionaram uma maior complexidade estrutural do hábitat à riqueza e abundância dos mais variados taxa. Contudo, este é um tema de difícil generalização e as abordagens experimentais ainda são raras. A vegetação é um elemento que proporciona complexidade estrutural ao hábitat devido às diversas organizações arquiteturais de seus módulos. Diversos estudos demonstraram que os artrópodes associados às plantas são um dos grupos mais afetados pela arquitetura da vegetação, particularmente as aranhas. Logo, o objetivo deste estudo foi avaliar os possíveis efeitos da arquitetura da vegetação sobre a abundância e riqueza de guildas de artrópodes, com ênfase na comunidade de aranhas. O estudo foi dividido em duas partes: (1) uma pesquisa exploratória, cujo objetivo foi correlacionar diferentes elementos arquiteturais das plantas com a comunidade de artrópodes, de forma a avaliar se determinados grupos de artrópodes são mais ou menos abundantes em determinadas configurações arquiteturais da vegetação; (2) uma pesquisa experimental, cujo objetivo foi manipular a arquitetura vegetal agrupando e espaçando os ramos vegetativos, de forma a avaliar os efeitos da densidade vegetal sobre a comunidade de artrópodes. Um total de 17 espécies de plantas e oito características arquiteturais foi utilizado na pesquisa exploratória. Já o experimento foi feito para três espécies de plantas e repetido em duas estações climáticas diferentes (seca e chuvosa) para avaliação dos efeitos sazonais sobre a resposta da comunidade de artrópodes à manipulação arquitetural da vegetação. Todos os dados de abundância e riqueza de artrópodes foram expressos por unidade de biomassa de planta e a disponibilidade de presas para os predadores (i.e., o total de artrópodes exceto o grupo de predadores sendo estudado) foi colocada como co-variável. Os padrões de abundância da comunidade de aranhas foram fortemente correlacionados à arquitetura da vegetação, tanto na pesquisa experimental quanto na exploratória. Já as guildas de outros artrópodes, com algumas exceções, foram pouco afetadas pela arquitetura da vegetação. Algumas guildas de fitófagos tiveram padrões consistentes de distribuição em plantas com diferentes arquiteturas. Estes padrões, por sua vez, ocorreram tanto na pesquisa exploratória quanto na experimental. A abundância de parasitóides e predadores (exceto aranhas) foi mais explicada pela disponibilidade de presas do que pela arquitetura per se. O padrão de distribuição das aranhas sobre as plantas pode ser explicado, em grande medida, pelo favorecimento que determinadas arquiteturas proporcionam aos hábitos de forrageio de cada guilda. Já o padrão de abundância das guildas de fitófagos em plantas com diferentes arquiteturas provavelmente decorre de uma modulação da taxa de predação, uma vez que a arquitetura da planta está vinculada à disponibilidade de refúgios
Abstract: Habitat structure has been a recurrent subject in literature and there have been several researches that correlated a greater structural complexity of habitat to the richness and abundance of diverse taxa. However, this represents a subject of hard generalization and experimental approaches are still rare. Vegetation is an element that provides structural complexity to habitat due to diverse architectural organization of their modules. Many researches demonstrated that arthropods associated to plants are one of the most affected groups by the vegetation architecture, especially the spiders. Thus, the objective of present research was to evaluate possible effects of vegetation architecture on the richness and abundance of arthropod guilds, with special emphasis on spider community. The research was divided in two parts: (1) a survey research, whose objective was to correlate diverse architectural traits of plants with the arthropod community, this in order to assess whether certain groups of the arthropod community are more or less abundant in certain plant architectural configurations; (2) an experimental research, whose objective was to manipulate plant architecture by grouping and spacing the vegetative branches in order to evaluate the effects of plant density on the arthropod community. A total of 17 plant species and eight architectural traits was used in survey research, whereas the experiment was performed in three plant species and repeated in two seasons (dry and wet) for evaluation of seasonal effects on the arthropod community response to manipulation of the plant architecture. All data referring to arthropod abundance and richness were given per unit of plant biomass and the prey availability for predators (i.e., all arthropods except the group of predators being studied) was set as a covariate. The abundance patterns of spider community were strongly correlated to the plant architecture, both in experimental and in survey research. Nevertheless, the other arthropod guilds, with some exceptions, were weakly affected by vegetation architecture. Some phytophagous guilds had consistent patterns of distribution on plant with different architectural traits. These patterns, by the way, occurred as in survey as in experimental research. The abundance of parasitoids and predators (except spiders) was more explained by the prey availability than by the plant architecture per se. Patterns of spider distribution on plants can be quite explained by the advantages that some plant architectures provide to the foraging habits of each guild. Abundance patterns of phytophagous guilds on plants with different architectural traits, nevertheless, were probably due to modulation of predation rates, since the plant architecture could determine refuge availability
Mestrado
Mestre em Ecologia
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Hinz, Hilmar. "Ecology and habitat use of flatfishes". Thesis, Bangor University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429649.
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Gilbert, Andrew. "The Foraging and Habitat Ecology of Black Terns in Maine". Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/GilbertAT2001.pdf.
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Bonar, Richard Lloyd. "Pileated woodpecker habitat ecology in the Alberta foothills". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0010/NQ60276.pdf.
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Cornelius, Cintia. "Genetic and demographic consequences of human-driven landscape changes on bird populations the case of Aphrastura spinicauda (Furnariidae) in the temperate rainforest of South America /". Diss., St. Louis, Mo. : University of Missouri--St. Louis, 2006. http://etd.umsl.edu/r1821.
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Boenke, Morgan. "Terrestrial habitat and ecology of Fowler's toads (Anaxyrus Fowleri)". Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106500.
Testo completoAbstract (sommario):
Habitat loss is the primary driver of global amphibian declines and thus preserving habitat is our best hope for preserving species at risk. The habitat needs of amphibians are complex due to terrestrial and aquatic requirements throughout their life history. Many pond breeding amphibians spend the majority of their life cycle within terrestrial environments and thus terrestrial habitats are critical to their persistence. Cryptic and fossorial behavior makes observations of amphibians in terrestrial habitats difficult. Our knowledge of the terrestrial ecology of amphibians is therefore incredibly limited. I review the literature on habitat loss, amphibian declines and terrestrial habitat use by amphibians with specific attention to refuge seeking behavior (CHAPTER ONE). I used radio-tracking to investigate the behavior of Fowler's toads (Bufo fowleri) in the beach dune ecosystem of Long Point, Ontario. Refuge seeking behavior by these animals is associated with specific components of the dunes and is predictable based on elevation, slope and distance from the lakeshore. Refuge sites placement is not random, but instead represent a trade-off between risk and reward (CHAPTER TWO). Philopatry in Fowler's Toads is driven by fidelity to refugia. These locations are used repeatedly on consecutive days, and even when they are not new sites within 10 meters of the previous day's refuge are most often chosen. Occasionally, however toads relocate their refuge sites as much as 700 m overnight (CHAPTER THREE). This contributes to the wide variation in the home range sizes of Fowler's Toads, as does method of calculation and search effort, while there is little apparent influence of intrinsic biological factors. The effect of search effort on range size is reduced in robust location data sets with more than thirty locations for each animal. A minimum home range estimate of 3517m2 is suggested under the caveat that range sizes may have no hard upper limit (CHAPTER FOUR).La perte d'habitat est le principal facteur responsable du déclin des amphibiens à l'échelle mondiale. La préservation de leur habitat représente donc le meilleur espoir pour la conservation de ces espèces en péril. Les amphibiens ont des besoins en complexes en matière d'habitat, car leur cycle de vie comprend des exigences terrestres ainsi qu'aquatiques. Plusieurs amphibiens qui se reproduisent dans des étangs passent la majorité de leur vie dans des environnements terrestres, ces derniers sont donc essentiels à leur résilience. Leurs comportements fouisseur et cryptique rendent les amphibiens difficiles à observer dans leurs habitats terrestres. En conséquence, notre connaissance de l'écologie terrestre des amphibiens est très limitée. Je passe en revue la littérature scientifique sur la perte d'habitat, le déclin des amphibiens et l'utilisation d'habitats terrestres par les amphibiens avec une attention particulière à la recherche de refuges (CHAPITRE UN). J'ai utilisé le pistage radioélectrique pour étudier le comportement des crapauds de Fowler (Bufo fowleri) dans l'écosystème de dunes de la plage de Long Point, en Ontario. La recherche de refuge par ces animaux est associée à des composants spécifiques des dunes et est prévisible selon l'élévation, la pente et la distance du bord du lac. L'emplacement du refuge n'est pas aléatoire, mais représente plutôt un compromis entre risque et récompense (CHAPITRE DEUX). La philopatrie chez les crapauds de Fowler est due à la fidélité aux refuges. Ces endroits sont utilisés de façon répétée sur plusieurs jours consécutifs ; même lorsqu'ils sont abandonnés, les crapauds choisissent le plus souvent un nouveau site à moins de 10 mètres du refuge de la journée précédente. A l'occasion, cependant, les crapauds peuvent délocaliser leurs sites de refuge jusqu'à 700 m d'une nuit à l'autre (CHAPITRE TROIS). Cela contribue à la grande variation dans le calcul de la taille du territoire des crapauds de Fowler. Les méthodes d'évaluation et l'effort de recherche contribuent aussi à cette variation, alors qu'il y a peu d'influence apparente des facteurs biologiques intrinsèques. De plus, l'effet de l'effort de recherche sur la taille du territoire est réduit lorsque les données de localisation sont robustes et comprennent plus de trente sites par animal. Une estimation de taille minimale du territoire des crapauds de Fowler de 3517 m2 est suggérée ici, sous la réserve que l'aire totale de répartition peut ne pas avoir de limite supérieure (CHAPITRE QUATRE).
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Donaldson, Lynda. "Conservation and ecology of wetland birds in Africa". Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/31812.
Testo completoAbstract (sommario):
Conservation managers worldwide are increasingly faced with the challenges of managing and protecting fragmented landscapes, largely as a consequence of human activities. Over recent decades, ecological theory has made a significant contribution to the development of landscape-scale conservation and practice. However, recommendations accounting for what is practically achievable in the modern-day landscape are currently lacking, while criteria for conservation planning and prioritisation continue to neglect the role of habitat networks at the required spatial scale for the long-term persistence of biodiversity. In this thesis, I test and apply ideas surrounding the complexities of managing and conserving species in a landscape context, using a suite of bird species endemic to papyrus (Cyperus papyrus) swamps in East and Central Africa as a model system. In the face of large-scale habitat loss and degradation, practical measures that account for the fragmented nature of this system, the needs of multiple specialist species, and the reliance on this habitat by local people, are urgently required. I first review the concepts originating from reserve design theory to provide a decision-making framework for those involved in landscape-scale conservation amid 21st century challenges to biodiversity, highlighting the key principles to be considered for informed choices to be made. Second, I show that the needs of local people can be compatible with conservation planning in the tropics, and may play an important part in maintaining habitat quality for species residing in historically disturbed landscapes. Third, I develop a novel framework to make an explicit link between metapopulation dynamics and conservation planning. Despite differences in the patch-level dynamics of individual species, areas of habitat where populations of multiple species are resistant to extinction, and resilient because of high chances of (re)colonization can be identified, highlighting where resources could be invested to ensure species have the capacity to respond to future change. Finally, I simulate the metapopulation dynamics of the papyrus-endemic birds to demonstrate that the optimal conservation strategy for the long-term persistence of all species residing in a network depends on the characteristics of individual species, and the total area that can be protected. Overall, this thesis develops and tests the ecological theory used in spatial conservation planning, emphasising the importance of habitat disturbance and interspecific ecological differences for the effective management of habitat networks. The results increase the evidence base for the conservation of wetland birds in Africa, as well as for species residing in fragmented landscapes more generally.
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McCleery, Robert Alan. "Urban fox squirrel ecology and management". Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/5908.
Testo completoAbstract (sommario):
I studied the habitat selection, survival, and anti-predator behaviors of the fox squirrel (Siurus niger) across the urban-rural gradient in College Station, Texas. From two years of tracking the radio locations of 82 fox squirrels, my data suggested that fox squirrels in urban areas selected for use large mast bearing trees that mimicked the habitat features they prefer in non-urban areas and avoided conifer and ornamental tree species. Urban fox squirrels selected to use buildings and non-native grass during certain seasons and showed a tolerance for pavement, including it proportionally in their core-areas. Analysis of radio-telemetry data of urban and rural fox squirrels suggested that the rates of survival and causes of mortality differed between the two populations. At least 60% of the mortalities on the rural site were caused by predation, while < 5% of the mortalities on the urban site were caused by predation. Most of the mortalities on the urban site (>60%) were cause by vehicular collisions. Observations of anti-predator behaviors supported my hypothesis that squirrels decrease their anti-predator behaviors as the human presence increases. Observational data also supported my hypothesis that this phenomenon was caused by habituation. I also found that the time dedicated to anti-predator behaviors differed among urban, rural, and suburban fox squirrel populations in response to coyote and hawk vocalizations. The mean responses to both vocalizations on the rural site (coyote = 45%, hawk = 55%) were at least twice that of those found on the urban sites (coyote = 11%, hawk = 20%). I also used survey responses to questions about squirrel management to test theoretical frameworks linking attitudes to behaviors. My data suggests that beliefs and attitudes that are modified by variables shown to increase accessibility generally correspond better to behaviors. My data also suggests that the inclusion of a measure of previous behaviors will increase the predictive ability of models within different theoretical frameworks. Most importantly for the advancement of a comprehensive theoretical framework, my study showed that composite models combining components of the theory of reasoned action and attitude to behavioral process models out-performed other models.
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Alexander, John D. "Bird-habitat relationships in the Klamath/Siskiyou mountains /". View full-text version online through Southern Oregon Digital Archives, 1999. http://soda.sou.edu/awdata/040226a1.pdf.
Testo completoAbstract (sommario):
Thesis (M.S.)--Southern Oregon University, 1999.Typescript. Includes bibliographical references (leaves 76-80). Also available via Internet as PDF file through Southern Oregon Digital Archives: http://soda.sou.edu. Search Bioregion Collection.
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Jones, Carys Wynn. "Habitat and rest site selection in polymorphic Lepidoptera". Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358332.
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Villastrigo, Carbajo Adrián. "Macroevolutionary patterns of habitat transitions in aquatic Coleoptera". Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/668249.
Testo completoAbstract (sommario):
Understanding the evolutionary processes underlying extant biodiversity may help us to comprehend why species richness is not equally distributed between clades. One of the main causes to explain the disparity of species richness is the development of key innovations in particular clades, increasing or decreasing their capabilities to occupy new environments, to exploit novel resources or to cope with competition. The present thesis focuses on explaining the macroevolutionary consequences of two of the most common habitat transitions in aquatic environments: between environments with different degree of salinity, and between running and standing waters. Among inhabitants of aquatic environments aquatic Coleoptera are one of the most diverse, with representatives living in all kind of environments, including both running and standing waters and, not infrequently, saline environments. The most speciose aquatic Coleoptera families living in aquatic habitats are Hydrophilidae, Dytiscidae and Hydraenidae, but only the evolution of the ecological transitions of the former have been previously studied under a phylogenetic perspective. In this thesis, we assessed the evolutionary patterns of selected tribes belonging to the other two families. Despite aquatic Coleoptera being a relatively well-studied fauna, we needed to address several systematic modifications that revealed the true evolutionary history of the studied groups, describing a genus and three subgenera of Hygrotini, plus other modifications of both Hygrotini and Ochthebiini taxonomy (Chapters 1 and 3), setting the basis of this thesis.
Transitions between environments with different degree of saline waters was addressed for Hygrotini (Dytiscidae family, Chapter 2) and Ochthebiini (Hydraenidae family, Chapter 5). We detected multiple origins of tolerance to saline waters, with a gradual acquisition in almost all cases and only direct transitions to hypersaline waters in fairly isolated clades, mostly associated with coastal rockpools. Moreover, tolerance to hypersaline waters was found to be irreversible, but it did not follow an evolutionary dead-end pattern as lineages exhibiting this trait still maintain their diversification capabilities (as seen in Cobalius subgenus, Chapter 5). Additionally, our results seem to link the origin of lineages exhibiting tolerance to saline waters to periods of global aridification, in accordance with previous studies in Hydrophilidae. Transitions between running and standing waters were studied in Hydroporini (Dytiscidae family, Chapter 6). We unveiled that species living in lotic and lentic habitats display similar diversification patterns, but the habitat preference is affecting the body size of the species, with reduced body sizes in specialized environments (i.e. smaller species in running waters). Finally, the field sampling in saline habitats led to the discovery of a new species for science, described as Ochthebius (Micragasma) minoicus (Chapter 4).Estudiar los procesos evolutivos que ocasionan la biodiversidad actual puede ayudarnos a comprender mejor como la riqueza de especies está distribuida de forma desigual en diferentes clados. Una de las causas principales para explicar este fenómeno es el desarrollo de innovaciones clave que modifican las capacidades de las especies para sobrevivir en nuevos ambientes, acceder a nuevos recursos, o para lidiar la competencia con otras especies. Esta tesis se focaliza en explicar las consecuencias macroevolutivas de dos de las transiciones de hábitat más comunes en ecosistemas acuáticos: aquellas entre ecosistemas con diferente nivel de salinidad, y aquellas entre ecosistemas de aguas corrientes y aguas estancas. Entre los habitantes de ambientes acuáticos, los escarabajos son uno de los grupos más diversos, con especies capaces de vivir en todo tipo de ambientes, incluyendo aguas corrientes y estancas, y en ocasiones, ambientes salinos. Las familias más diversas de escarabajos acuáticos son Hydrophilidae, Dytiscidae e Hydraenidae, aunque solo la primera ha sido estudiada desde una perspectiva evolutiva. En esta tesis, evaluamos los patrones evolutivos de varias tribus pertenecientes a las otras 2 familias. A pesar de que los escarabajos acuáticos son un grupo bien estudiado en general, ha sido necesario realizar modificaciones en la clasificación de algunos grupos para reflejar su verdadera historia evolutiva, describiendo un nuevo género y tres subgéneros para la tribu Hygrotini. Adicionalmente, se han realizado pequeñas modificaciones tanto en Hygrotini como en Ochthebiini, siendo la base sobre la que se han desarrollado los posteriores estudios filogenéticos de esta tesis. Las transiciones entre ambientes con diferente nivel de salinidad han sido estudiadas para Hygrotini (familia Dytiscidae, Capítulo 2) y Ochthebiini (familia Hydraenidae, Capítulo 5). Se han detectado múltiples orígenes de la tolerancia a la salinidad, adquiriéndose esta característica de forma gradual en la mayoría de los casos. Los casos en los que se han descubierto transiciones directas de ambientes de agua dulce hacia ambientes hipersalinos, son clados aislados en la filogenia y asociados con ambientes de charcas costeros. Además, la tolerancia de aguas hipersalinas ha demostrado ser una característica irreversible, aunque no por ello se trata de un dead-end evolutivo (callejón sin salida), ya que las especies que viven en estos ambientes conservan su capacidad de diversificación, llegando incluso a ser superior a la de otras especies (por ejemplo, el subgénero Cobalius, Capítulo 5). A si mismo, nuestros resultados relacionan el origen de linajes tolerantes a la salinidad con periodos de aridificación a escala global, un patrón que confirma el encontrado en la familia Hydrophilidae. En cuanto a las transiciones entre aguas corrientes y estancas estudiada en Hydroporini (familia Dytiscidae, Capítulo 6), hemos encontrado patrones similares en las especies que viven en ambos ambientes, aunque los análisis sugieren la posibilidad de una mayor tasa de diversificación en ambientes de aguas estancadas. Nuestros resultados han destacado una correlación entre la preferencia del hábitat de las especies con su tamaño corporal, de manera que las especies que se encuentran en ambientes más especializados (en aguas corrientes) son aquellas con menor tamaño. Adicionalmente, se ha demostrado que la transición entre ambientes no es per se un factor que afecta al tamaño corporal de las tesis. Finalmente, gracias a los numerosos trabajos de campo realizados enfocados en los ambientes salinos, se ha podido describir la especie Ochthebius (Micragasma) minoicus (Capítulo 4).
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Bartholomew, Aaron. "New dimensionless indices of structural habitat complexity". W&M ScholarWorks, 2001. https://scholarworks.wm.edu/etd/1539616561.
Testo completoAbstract (sommario):
Ecologists have long known that complex habitats often provide prey with refugia from predation in a wide variety of habitat types and for a wide variety of prey species. Despite the recognized importance of structural habitat complexity, ecologists have measured complexity in many different ways. I propose four new indices of structural habitat complexity that are dimensionless, that can be applied across various habitat types and scales, and that directly measure how structural complexity interferes with a predator's foraging ability. These indices are: (1) Ct/At, the total area of cover within a habitat (Ct) divided by the area of the habitat (At), (2) Cw/Pw, the average width of the individual structures within a habitat (Cw) divided by the appropriate width of the prey organism (Pw), (3) Sp/Pr, the average inter-structural space size within a habitat (Sp) divided by the width of the predator (Pr), and Sp/Py, the average inter-structural space size within a habitat (Sp) divided by the width of the prey (Py). I predicted that prey survivorship should (1) increase hyperbolically with increasing Ct/At, (2) increase hyperbolically with increasing Cw/Pw, and (3) decrease sigmoidally with increasing Sp/Pr. I also predicted that different sized fauna should respond differently to artificial seagrass plots deployed in a seagrass bed, based upon the size of the inter-structural spaces relative to their body sizes (Sp/Py). I found that prey survivorship increased hyperbolically with increasing Ct/At, and decreased sigmoidally with increasing Sp/Pr. I found no effect of Cw/Pw on prey survivorship. I found that small fauna responded positively to increased structure in artificial seagrass plots deployed in a seagrass bed, but after controlling for structural surface area within each plot there was no difference between treatments, indicating no effect of Sp/Py on small fauna. Larger fauna responded slightly differently than the small fauna, but the pattern of their response did not support the hypothesis that Sp/Py was important. The smaller fauna also appeared to respond positively to increased water flow speeds within the seagrass bed. Overall, these indices may be useful to both ecologists and managers interested in predator-prey-habitat issues.
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Lindsey, Peter Andrew. "The feeding ecology and habitat use of the aardvark (Orycteropus afer)". Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-11162006-100552/.
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Gonzalez, Andrew. "Extinction : the role of habitat fragmentation and environmental variability". Thesis, Imperial College London, 1998. http://hdl.handle.net/10044/1/12032.
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Battocletti, Amy. "The Population and Ecological Genetic Effects of Habitat Fragmentation". Thesis, Georgetown University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10273271.
Testo completoAbstract (sommario):
Maintaining intraspecific variation is important for populations’ long-term success and is increasingly being recognized as an important conservation goal. Populations in anthropogenically fragmented habitats may lose variation rapidly via genetic drift, particularly in small fragments with a high ratio of edge to interior habitat. We studied the population and ecological genetic effects of habitat fragmentation on both a foundation plant, Spartina patens, and a dependent herbivore, Tumidagena minuta, using a naturally fragmented, salt marsh model system. We employed microsatellite marker analyses to estimate various measures of genetic variation, including allelic richness and heterozygosity, and to estimate the strength of genetic drift using estimates of effective population size (Ne). To achieve this, we developed a new program to estimate Ne and developed new markers for S. patens from genome sequence data. We found lower S. patens genetic variation and lower T. minuta Ne near the S. alterniflora edges, indicating that T. minuta experience stronger genetic drift near edges. These findings reinforce the importance of habitat patch shape in influencing populations.
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Slater, Matthew James. "The sea cucumber Australostichopus mollis: Juvenile feeding ecology and habitat". Thesis, University of Auckland, 2009. http://hdl.handle.net/2292/5833.
Testo completoAbstract (sommario):
The aspidochirote sea cucumber Australostichopus mollis is a commercially valuable species of research interest as a candidate for aquaculture or polyculture. Understanding juvenile habitat and feeding biology is essential to furthering aquaculture efforts and expanding knowledge of the ecology of the species. Surveying within the Mahurangi Harbour, New Zealand, revealed highly patchy distribution of juvenile A. mollis at one site within an area of high adult density. High juvenile density correlated with sediment qualities favouring epibenthic detritivorous deposit-feeding. Juvenile A. mollis showed no distinct spatial separation from adults and no association with dense macroalgae or preference for shallower depths than adults, as may be expected from studies on other sea cucumber species. Wild caught juveniles displaced to non-juvenile habitats with novel surface sediments showed rapid growth. The results indicate that the highly patchy distribution of juveniles in the harbour is not due to differences in the food quality of sediments but rather other localised effects. Juvenile A. mollis show an ability to exploit a variety of benthic sediment food sources, with growth rates comparable to other cultured species. Juvenile A. mollis exhibited positive selectivity for organic particles both in situ and in the laboratory. Juveniles exhibited an ability to distinguish between different sediment TOM levels, an ability which became limited once TOM exceeded 3%. The results reiterate the specific nutrient recycling role of deposit-feeding sea cucumbers and may help explain the patchy distribution of juvenile sea cucumbers in heterogeneous habitats. In addition the research indicates that diet homogeneity and stability will be important in development of A. mollis artificial diets while a broad range of artificial diet grain sizes will be consumed. Juvenile A. mollis fed a high rate of mussel waste diet over three months exhibited significantly higher specific growth rate (SGR) than those fed natural sediment or algal diets. The results indicate the suitability of mussel waste as a juvenile diet and show that rapid growth can be expected among juvenile sea cucumbers cultured beneath mussel farms provided sea cucumber stocking rates are managed appropriately. Bioavailability of potential artificial diet ingredients was also systematically tested for juvenile A. mollis. Apparent digestibility was moderate for common carbohydrate sources and excellent for a range of artificial protein sources including low-cost protein sources. However, growth on artificial diets was poor and diet performance may need to be improved using fermentation steps or similar before they become viable. Rapid growth and flexible feeding preferences show A. mollis to be well suited to future aquaculture and polyculture.
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Collins, Rita. "Urban Coyote (Canis latrans) Ecology| Diet, Activity, and Habitat Use". Thesis, California State University, Long Beach, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10826343.
Testo completoAbstract (sommario):
Non-habituated coyotes (Canis latrans) avoid direct interactions with humans. Reliance on human food sources has been linked to gradual habituation, a precursor to conflict and attacks on domestic pets and humans. Diet and activity patterns of urban coyotes inhabiting natural fragments in Long Beach, CA were monitored through scat collection and camera trapping over a year (Aug 2016 – Aug 2017). Local urban coyotes are relying predominately on natural foods, with an increase in mammalian prey in the wet season and an increase in vegetation and insect consumption in the dry season. Anthropogenic items, food and food related inedible items, appeared in 14% of scats overall, with no significant seasonal change. Cat remains were found in 14% of scat samples, but only triggered cameras once throughout the 2,857 camera nights of the study. Coyote activity was centered on nights in both seasons, with greater dawn activity in the dry season, indicating an avoidance of peak human activity. This reliance on natural foods and avoidance of human activity reduces the opportunities for human-wildlife conflicts in our local area.
18
Nelson, Josiah. "Habitat Use and Foraging Ecology of Bats in North Dakota". Diss., North Dakota State University, 2016. http://hdl.handle.net/10365/25849.
Testo completoAbstract (sommario):
Habitat use is a key component to understanding the conservation needs of species. While an array of quantitative analyses for studying fine-scale habitat use and selection have been developed, such methods have rarely been applied to bat species, with most work focused at a broad scale or using qualitative methods. Insectivorous bat communities face major threats from habitat conversion, exploitation of natural resources, and the impending spread of white-nose syndrome. Hence, detailed knowledge of their habitat needs is critical for developing effective management plans. In North Dakota, little was known about local bat populations prior to 2009, with essentially no knowledge of habitat associations and preferences of bat species. The overall objective of this research was to survey habitats across North Dakota to document species occurrences within key ecological regions and to assess the influence of fine-scale habitat characteristics on community diversity and foraging patterns. We further aimed to assess the foraging habitat selection of little brown bats, Myotis lucifugus, a species of conservation concern. Our specific objectives were to: 1) assess species? occurrence and distributions within North Dakota; 2) assess the influence of habitat and the availability of water resources on species diversity and community-level foraging activity; 3) identify habitats associated with areas of high foraging activity; 4) identify indicator species that characterize key habitats; 5) assess foraging habitat selection of female M. lucifugus; 6) and assess individual variation in habitat selection of M. lucifugus. From 2009 to 2012, mist netting and acoustic surveys were conducted to document species occurrence at 68 sites. From 2012 to 2015, targeted acoustic surveys were conducted at 37 sites to assess foraging activity levels in variable habitats. In 2014 and 2015, data-logging telemetry receivers were used to assess foraging habitat selection of M. lucifugus. The presence of 11 species was confirmed in the state. We found that bat community diversity and foraging activity were influenced by fine-scale habitat characteristics. M. lucifugus selected for edge habitats and nearby water sources. These results will be valuable for the conservation and management of bats and provide baseline information for future research on habitat use of bats.North Dakota Game and Fish Department
19
Blaney, Weston Douglas. "An Institute for Urban Agriculture: Architecture, Ecology and Urban Habitat". Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/35895.
Testo completoAbstract (sommario):
Humankind has lived on earth for a geologically brief time. Our species has proven a remarkable ability to adapt to our environment through the development and use of tools and technology. Little evidence suggests when our need to tame nature took hold in our collective cultural consciousness, yet throughout western history, human needs and activities have been perceived as separate from the natural world. We stand at the beginning of a new millennium, aware of the cycles which govern the flows of life on our planet, yet far from understanding the specifics of how they work.
This building, an Institute for Urban Agriculture, seeks to challenge that notion of separation. The design expresses architecturally the ways in which the technological systems and organic systems work together to sustain the mission of the Institute. Through every aspect of the building design, the perceived separation of those systems is woven together to express an holistic view of the building as a fully integrated system. Human intervention is a necessary part of a healthy urban ecosystem, and positive relationships with the natural world contribute to the qualities of human health. Inspired by careful observation and experience of the surrounding urban landscape, this design recognizes those interactions and builds upon their social, ecological and economic values. Architecture becomes the medium for communicating transformed ideas about our relationships with the natural world to the building inhabitants and to the public at large.Master of Architecture
20
Losee, Michele J. "Habitat Characteristics and Nesting Ecology of Golden Eagles in Arizona". Antioch University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1563035697672681.
Testo completo
21
Berkelman, James. "Habitat Requirements and Foraging Ecology of the Madagascar Fish-Eagle". Diss., Connect to this title online, 1997. http://scholar.lib.vt.edu/theses/available/etd-5852152749721461/.
Testo completo
22
Herse, Mark Richard. "Landscape ecology of two species of declining grassland sparrows". Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/35786.
Testo completoAbstract (sommario):
Master of ScienceDepartment of Biology
Alice Boyle
Species extinctions over the past two centuries have mainly been caused by habitat destruction. Landscape change typically reduces habitat area, and can fragment contiguous habitat into remnant patches that are more subject to anthropogenic disturbance. Furthermore, changes in the landscape matrix and land-use intensification within remaining natural areas can reduce habitat quality and exacerbate the consequences of habitat loss and fragmentation. Accordingly, wildlife conservation requires an understanding of how landscape structure influences habitat selection. However, most studies of habitat selection are conducted at fine spatial scales and fail to account for landscape context. Temperate grasslands are a critically endangered biome, and remaining prairies are threatened by woody encroachment and disruptions to historic fire-grazing regimes. Here, I investigated the effects of habitat area, fragmentation, woody cover, and rangeland management on habitat selection by two species of declining grassland-obligate sparrows: Henslow’s Sparrows (Ammodramus henslowii) and Grasshopper Sparrows (A. savannarum). I conducted >10,000 bird surveys at sites located throughout eastern Kansas, home to North America’s largest remaining tracts of tallgrass prairie, during the breeding seasons of 2015 and 2016. I assessed the relative importance of different landscape attributes in determining occurrence and within-season site-fidelity of Henslow’s Sparrows using dynamic occupancy models. The species was rare, inhabited <1% of sites, and appeared and disappeared from sites within and between seasons. Henslow’s Sparrows only settled in unburned prairie early in spring, but later in the season, inhabited burned areas and responded to landscape structure at larger scales (50-ha area early in spring vs. 200-ha during mid-season). Sparrows usually settled in unfragmented prairie, strongly favored Conservation Reserve Program (CRP) fields embedded within rangeland, avoided trees, and disappeared from hayfields after mowing. Having identified fragmentation as an important determinant of Henslow’s Sparrow occurrence, I used N-mixture models to test whether abundance of the more common Grasshopper Sparrow was driven by total habitat area or core habitat area (i.e. grasslands >60 m from woodlands, croplands, or urbanized areas). Among 50-ha landscapes containing the same total grassland area, sparrows favored landscapes with more core habitat, and like Henslow’s Sparrows, avoided trees; in landscapes containing ~50–70% grassland, abundance decreased more than threefold if half the grassland area was near an edge, and the landscape contained trees. Effective conservation requires ensuring that habitat is suitable at spatial scales larger than that of the territory or home range. Protecting prairie remnants from agricultural conversion and woody encroachment, promoting CRP enrollment, and maintaining portions of undisturbed prairie in working rangelands each year are critical to protecting threatened grassland species. Both Henslow’s Sparrows and Grasshopper Sparrows were influenced by habitat fragmentation, underscoring the importance of landscape features in driving habitat selection by migratory birds. As habitat loss threatens animal populations worldwide, conservation efforts focused on protecting and restoring core habitat could help mitigate declines of sensitive species.
23
Collett, Matthew. "Influences of resource distribution on ecology and behaviour". Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300135.
Testo completo
24
Murphy, Nathan L. "Syntopic coexistence and habitat usage in two morphologically similar Plethodon species". [Bloomington, Ind.] : Indiana University, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3219894.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2006."Title from dissertation home page (viewed June 27, 2007)." Source: Dissertation Abstracts International, Volume: 67-06, Section: B, page: 2934. Adviser: Craig Nelson.
25
Smith, Heidi. "The hydro-ecology of limestone springs in the Wye Valley, Derbyshire". Thesis, University of Huddersfield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327144.
Testo completo
26
Lindsey, Peter Andrew. "The feeding ecology and habitat use of the aardvark (Orycteropus afer)". Diss., University of Pretoria, 1999. http://hdl.handle.net/2263/29491.
Testo completoAbstract (sommario):
The seasonal diet, feeding patterns, feeding selection and habitat selectivity of the aardvark were determined during summer and winter at Tussen die Riviere Nature Reserve in the southern Free State. Pitfall trapping, dig sampling and quadrat sampling were used to determine the resource base of three habitats in the summer and winter of 1998. A total of 44 ant species of 5 sub families and 17 genera, and two termite species of two sub families were recorded. Pitfall trapping was the most successful technique, followed by quadrat sampling (51.1%) and finally, dig sampling (48.8%). Abundance and diversity was higher during summer than winter. Monomorium albopilosum was the most abundant species in all habitats in winter, whilst Anoplolepis custodiens was the most abundant in summer. The grassland habitat yielded the highest abundance and diversity, followed by the steep slope and riverine areas. Seasonal diet and foraging patterns were determined through faecal analysis and observation of four habituated aardvarks. The Formicidae were more important than the Isoptera in both seasons. The feeding of the aardvark was highly selective, only 28.8% of the available species having been utilised. Prey selection was found to be most highly correlated with prey size, prey abundance, prey mobility, and prey calorific value. Aardvarks were highly selective in their habitat utilisation. The vast majority of feeds were made in the grassland areas where prey abundance was greatest, compared to negligible numbers of prey in the rocky steep slopes and no prey in the riverine areas due to periodic flooding.Dissertation (MSc (Veterinary Tropical Diseases)--University of Pretoria, 1999.
Veterinary Tropical Diseases
unrestricted
27
Garpe, Kajsa. "Effects of habitat structure on tropical fish assemblages". Doctoral thesis, Stockholm University, Department of Zoology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6767.
Testo completoAbstract (sommario):
Rates of habitat alteration and degradation are increasing worldwide due to anthropogenic influence. On coral reefs, the loss of live coral reduces structural complexity while facilitating algal increase. In many coastal lagoons seagrass and corals are cleared to make room for cultivated macroalgae. This thesis deals with reef and lagoon habitat structure and how fish assemblage patterns may be related to physical and biological features of the habitat. It further examines assemblage change following habitat disturbance. Four studies on East African coral reefs concluded that both the abundance and species richness of recruit and adult coral reef fish were largely predicted by the presence of live coral cover and structural complexity (Papers I-III, VI). Typically, recruits were more selective than adults, as manifested by limited distributions to degraded sites. Paper VI compared short- and long-term responses of fish assemblages to the 1997-1998 bleaching event. The short-term response to coral mortality included the loss of coral dwelling species in favour of species which feed on algae or associated detrital resources. Counterintuitively, fish abundance and taxonomic richness increased significantly at one of two sites shortly after the bleaching. However, the initial increase was later reversed and six years after the death of the coral, only a limited number of fish remained. The influence of fleshy algae on fish assemblages was studied in algal farms (Paper IV), and examined experimentally (Paper V). The effects of algal farming in Zanzibar were significant. Meanwhile, manually clearing algal-dominated patch reefs in Belize from macroalgae resulted in short-term increases of abundance, biomass and activity of a few species, including major herbivores. The findings of this thesis demonstrate the significance of habitat as a structuring factor for tropical fish assemblages and predicts that coral death, subsequent erosion and algal overgrowth may have substantial deleterious impacts on fish assemblage composition, abundance and taxonomic richness, with recovery being slow and related to the recovery of the reef framework.
28
Zolkowski, Stephanie B. "Habitat relationships of bird communities in Wisconsin peatlands /". Link for full-text, 2008. http://epapers.uwsp.edu/thesis/2008/Zolkowski.pdf.
Testo completo
29
Walsh, Allyson Louise. "Foraging habitat, weather and the conservation of bats in Britain". Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294573.
Testo completo
30
May, Cassandra J. "Habitat Mapping and Predator-Prey Dynamics in Ohio Resevoirs". The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1364461349.
Testo completo
31
Bueno, Marília 1982. "Caracterização de microhabitats formados por algas calcáreas e sua utilização pelos anfípodes em costões rochosos do litoral norte de São Paulo". [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315912.
Testo completoAbstract (sommario):
Orientador: Fosca Pedini Pereira LeiteTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-27T11:20:12Z (GMT). No. of bitstreams: 1 Bueno_Marilia_D.pdf: 1421870 bytes, checksum: 37eb3d9230e7741798f121407dee5d97 (MD5) Previous issue date: 2015
Resumo: Algas calcáreas articuladas estão presentes em costões rochosos ao redor do mundo e formam densos tapetes, os quais abrigam uma fauna muito rica de invertebrados. Dentre eles, os anfípodes são dominantes e sua associação com estas algas foi investigada. Inicialmente foi feita a caracterização do habitat. A biomassa das algas e a abundância total dos anfípodes não diferiram entre as estações do ano, já a composição de espécies de anfípodes apresentou variação, a qual foi atribuída principalmente ao padrão de ocorrência de duas espécies de hialídeos, Apohyale media e Hyale niger, que são dominantes nas algas calcáreas. A biomassa das algas também não variou conforme exposição à ação de ondas. Diferenças na abundância total dos animais foram observadas, sendo encontrados mais animais nos costões mais expostos às ondas. Neste tópico, os tanaidáceos foram incluídos e apenas duas espécies foram encontradas, cada uma associada à um grau de exposição à ação de ondas. Leptochelia aff. dubia foi encontrada apenas nos costões abrigados, enquanto Zeuxo coralensis apenas em costões expostos. Os tapetes de algas coralinas são verticalmente extensos a ponto de terem características físicas (quantidade de sedimento e tamanho de grãos) e biológicas (abundância e composição de espécies de anfípodes) distintas entre as zonas superior e inferior do mesmo tapete. Após a caracterização do habitat, sua utilização pelos anfípodes foi examinada com relação à estrutura (arquitetura) das algas, a altura de ocorrência das algas no costão rochoso e o papel do sedimento na seleção deste habitat. O volume intersticial foi extremamente variável dentre as cinco algas estudadas entretanto, para todas as algas, quanto maior o volume intersticial, maior a abundância dos anfípodes. O habitat formado pelas coralinas, independente da altura no costão, parece ser o fator mais importante na seleção pelos anfípodes. Com relação ao sedimento, sua retenção nos tapetes de algas não se mostrou sazonal e não foi observada relação com a abundância dos anfípodes. Os experimentos de laboratório corroboraram o padrão observado em campo e não indicaram um importante efeito da adição do sedimento na seleção de habitat pelos hialídeos. A malha intrincada formada pelas frondes das algas calcáreas permite a retenção, além do sedimento e da matéria orgânica associada à ele, de diferentes tipos de alimento como microalgas e componentes da meiofauna. Essa gama de itens alimentares pode ser importante na seleção deste local pelos anfípodes, já que a alimentação da alga em si não ocorre, e explicaria a grande variedade de hábitos alimentares apresentados pelos anfípodes associados. A seleção do habitat de coralinas pode também estar relacionada à proteção contra a dessecação, já que retenção de água entre as frondes mantém o ambiente úmido nos períodos de emersão
Abstract: Articulated calcareous algae are distributed on rocky shores worldwide forming dense mats and harboring rich invertebrate assemblages. Amphipods are dominants and their association with coralline algae was investigated. First, the habitat characterization was done. Algae biomass and amphipods abundance did not differ among seasons, but species composition showed a variable pattern mainly in response to occurrence patterns of the dominant hyalids Apohyale media and Hyale niger. Algae biomass did not vary between degrees of wave exposure, however, more amphipods were found at exposed shores. Tanaids were included and an interesting spatial segregation was observed. Only two species were found, each one associated to a degree of wave exposure. Leptochelia aff. dubia was found at sheltered shores, while Zeuxo coralensis at exposed shores. Coralline mats are wide enough to have distinguished upper and lower zones based on physical (amount of sediment and grain size) and biological (amphipods abundance and species composition) features. After characterizing the habitat, its usage by the amphipods was examined through algae structure (architecture), height on shore and the effect of sediment loads on habitat selection. Interstitial volume was highly variable among the five algae studied and a strong positive relation between interstitial volume and amphipods abundance was observed. Coralline habitat, regardless of the height on shore, was probably the main factor governing habitat selection. Sediment retention at coralline mats was not seasonal and no relation with the amphipods was found. Laboratory experiments corroborate the observed field patterns and added sediment had no effect on habitat selection by the hyalids. The intricate canopy of coralline algae allowed retention, not only of sediment and organic matter, but also of microalgae and meiofauna. This wide array of food items may be important for coralline habitat selection by the amphipods, since they do not feed on coralline itself. In this case, coralline could be an important source of food, allowing the coexistence of amphipods having different feeding habits. Water retention may also play an important role, since habitats are maintained humid during emersion periods
Doutorado
Ecologia
Doutora em Ecologia
32
Gerber, Brian Daniel. "Comparing density analyses and carnivore ecology in Madagascar's southeastern rainforest". Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/36035.
Testo completoAbstract (sommario):
Madagascar is renowned for its biodiversity, but also for forest loss, fragmentation, and degradation, making it a global conservation priority. With few studies dedicated to Madagascarâ s carnivores, little is known about their ecology. My objectives were to 1) compare density estimation techniques applicable to enumerating rare and/or elusive carnivores, 2) investigate Malagasy carnivore distributions, abundance and density, and occupancy/use across four sites that vary in forest disturbance, and 3) explore temporal activity patterns of rainforest carnivores. I found the spatially-explicit-capture-recapture models were empirically superior, as they are flexible and account for spatial variation in detection probability and area estimation. I found both endemic and exotic carnivore composition varied among four rainforest sites: Primary, Selectively-logged, Fragments <2.5 km and Fragments >15 km from contiguous-primary rainforest. All endemic carnivores were present in the Primary and Selectively-logged rainforest, while endemic carnivore species richness decreased and exotic carnivore species richness increased in the fragmented forests. Malagasy civet (Fossa fossana) density ± SE was significantly less in the Selectively-logged compared to the Primary rainforest (1.38 ± 0.22, 3.19 ± 0.55 civets/km2, respectively); they were absent from both fragmented forests. Fossa (Cryptoprocta ferox) density ± SE was not different between the Primary and Selectively-logged rainforests (0.12 ± 0.05, 0.09 ± 0.04 adults/km2, respectively); a single animal was detected in the Fragments <2.5 km, while none were detected in the Fragments >15 km. Malagasy carnivores had varied temporal activity overlap (5.8-88.8%). C. ferox preferred crepuscular activity, but overall exhibited a cathemeral activity pattern.Master of Science
33
Scarbrough, David Lyle. "SEXUAL SEGREGATION BY DESERT MULE DEER (ARIZONA)". Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/291260.
Testo completo
34
Mackey, Tracy L. "Habitat Selection and Overwintering Survival of the Introduced Wall Lizard, Podarcis muralis". University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1291050368.
Testo completo
35
Falk, Judith A. "Landscape level raptor habitat associations in northwest Connecticut". Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-11182008-063418/.
Testo completo
36
Henderson, G. "Ecology of the Yellowhammer Emberiza citrinella in a mixed agricultural habitat". Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411195.
Testo completo
37
Broughton, Richard K. "Habitat modelling and the ecology of the marsh tit (Poecile palustris)". Thesis, Bournemouth University, 2012. http://eprints.bournemouth.ac.uk/20768/.
Testo completoAbstract (sommario):
Among British birds, a number of woodland specialists have undergone a serious population decline in recent decades, for reasons that are poorly understood. The Marsh Tit is one such species, experiencing a 71% decline in abundance between 1967 and 2009, and a 17% range contraction between 1968 and 1991. The factors driving this decline are uncertain, but hypotheses include a reduction in breeding success and annual survival, increased inter-specific competition, and deteriorating habitat quality. Despite recent work investigating some of these elements, knowledge of the Marsh Tit’s behaviour, landscape ecology and habitat selection remains incomplete, limiting the understanding of the species’ decline. This thesis provides additional key information on the ecology of the Marsh Tit with which to test and review leading hypotheses for the species’ decline. Using novel analytical methods, comprehensive high-resolution models of woodland habitat derived from airborne remote sensing were combined with extensive datasets of Marsh Tit territory and nest-site locations to describe habitat selection in unprecedented detail. Further fieldwork established the causes and frequency of breeding failure at the local population scale, and dispersal distances and success were quantified. Information from these studies was used to inform national-scale spatial analyses of habitat distribution in relation to the pattern of range contraction for the Marsh Tit and two other woodland bird species. The combined results indicate that Marsh Tits require extensive areas of mature woodland in order to accommodate large territories and short dispersal distances, with greatest selection for a woodland structure encompassing a tall, near-closed tree canopy and extensive understorey. The evidence suggests that nest-site competition, nest predation or deteriorating habitat quality have not driven the population decline. However, reduced connectivity between woodlands in the landscape, possibly due to hedgerow loss, may have interacted with increased mortality to precipitate population declines and local extinctions where habitat fragmentation was relatively high. The potential causes of increased mortality are discussed, along with priority areas for future research and the wider possible applications of remote sensing techniques in the field of woodland bird research.
38
Fussman, Jennifer Lynn. "Foraging ecology of Kirtland's Warblers in managed and natural breeding habitat". Connect to resource, 1997. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1260989687.
Testo completo
39
Ide, Junya. "Behavioural ecology and habitat utilization of the satyrine butterfly Lethe diana". 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/150030.
Testo completo
40
Wallace, Mark Christopher. "Elk habitat use in the White Mountains, Arizona". Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185690.
Testo completoAbstract (sommario):
I identified the seasonal ranges and migration routes for Rocky mountain elk (Cervus elaphus nelsoni) that summered on the White Mountains Apache Reservation (reservation). I described elk distributions, movements, diets, and behaviors related to habitats in the White Mountains, Arizona from October 1983 to July 1986. I identified neonatal elk hiding habitats and how long they were used. Adult and neonatal elk were captured and radio collared. I determined movements and habitat use from direct observations of marked elk relocated by radio-telemetry. Yearly home ranges in this population were large; 638.9 ± 465.2 (SE) km² and 385.7 ± 313.1 km² for males and females, respectively. Distances elk moved/day were greater in summer (7.5 ± 0.3 km) and fall (6.5 ± 0.4) than in winter (3.2 ± 0.2 km). In summer, males selected spruce (Picea spp.) forests and associated clear cuts while females selected mixed-conifer types. In winter, males selected juniper (Juniperus spp.) and cleared sites. Females selected junipers and cleared sites, but also selected meadows and mixed-confer sites. Daily and seasonal elk activity patterns were similar to those reported elsewhere. Seasonal segregation of male and female elk groups occurred and was most related to elevational (and associated habitat) differences. Females moved to higher elevations, following snowmelt, earlier than males in spring, but males moved to higher elevations than females by summer. In fall, males and females used habitats at mid-elevations. Females were more frequently seen in forested types than males which were often observed in small forest openings. Habitat differences in winter were mostly spatial rather than structural. Spring elk diets were dominated by grasses (57.8%), summer diets by forbs (65.6%), fall diets by grasses (35.2%) and forbs (37.9%), and winter diets by evergreen oaks (Quercus spp.) (41.0%). Diets were similar between sexes in all seasons. Neonatal elk hid until 16 days old. Calves <10 days old moved less than calves ≥10 days old. Calf hiding sites were in mid-elevational ponderosa (Pinus ponderosa) on gentle southwest slopes. Hiding cover 0.36 m to 1.70 m tall was the most important component of calf hiding sites.
41
Cole, Gemma Marie. "Spatial ecology and habitat use of bobtail lizards (Tiliqua rugosa) in urban and peri-urban habitats across Perth". Thesis, Cole, Gemma Marie (2021) Spatial ecology and habitat use of bobtail lizards (Tiliqua rugosa) in urban and peri-urban habitats across Perth. Honours thesis, Murdoch University, 2021. https://researchrepository.murdoch.edu.au/id/eprint/63410/.
Testo completoAbstract (sommario):
Bobtail lizards, Tiliqua rugosa, have been studied extensively in South Australia, with the majority of studies focusing on the population near Mt Mary. There is a substantial lack of literature from other localities, including Perth, Western Australia, as well as on the impact urbanization is having on this species. This study aimed to gain an insight on the spatial ecology and habitat use of bobtails local to the Perth region. Lizards held small home ranges (mean 1.4ha) that did not differ between urban and peri-urban locations. There was no significant correlation between home range size and remnant bushland patch size nor were there any associations between home range and lizard morphometrics. Home range did overlap between individuals inhabiting the same reserve. Several lizards were preferentially selecting microhabitat composition at locations where they were observed inactive and using these habitat as a refuge. However there was not one particular variable that was responsible for this significant difference but cover at several levels; namely leaf litter, canopy, low shrub, and grass trees were important. This represents their flexibility in utilizing a range of different microhabitat structures, both for refuge and when active. The bobtail lizards were recorded reaching their optimum body temperature between 12pm to 3pm for most of the year regardless of the season. Flexibility in microhabitat use as well as their ability to maintain small home ranges while rarely moving beyond the bushland patch boundary is likely why they are adapted to urban living. Due to their flexibility and ability to maintain their home range within small reserves it is important to ensure a variety of vegetation and habitat structures are available for the lizards to seek shelter under. Given that the lizards were rarely moving outside of their reserve boundaries, in order to prevent them crossing roads and potentially getting struck by cars, leaving a border around the edge of the reserve with no vegetation to encourage them to stay with the sheltered reserve.
42
Keyes, Kristen. "Geographic and habitat fidelity in the short-eared owl (Asio flammeus)". Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103752.
Testo completoAbstract (sommario):
Over the past half a century, the Short-eared Owl (Asio flammeus) has experienced a severe population decline across North America. Many aspects of Short-eared Owl natural history are poorly understood, thus hampering the development of effective management plans. The overall goal of this thesis was to help to fill the knowledge gaps that exist, and at the same time provide a foundation for future studies. The specific objectives were three-fold: 1) to investigate Short-eared Owl spatial origins across North America in the context of nomadic, migratory and/or philopatric movements; 2) to develop a practical visual survey protocol aimed at improving monitoring efforts and facilitating assessments of across season landscape-level habitat use; and 3) to describe nest site characteristics, success, and causes of failure. Stable isotope analysis was used to investigate spatial origins of Short-eared Owls, and while exploratory in nature, evidence was provided that the species may exhibit different movement strategies across their North American range. The volunteer visual survey protocol developed here was successful over a trial period, and should become a reliable monitoring scheme to track abundance and distribution through time. Based on the comparison of sites 'used' versus 'available' on two islands on Lake Ontario near Kingston, in eastern Ontario, the Short-eared Owl's use of forest cover during the winter appears to be dependent on seasonal effects. Also, during the breeding season in this geographical area, grazed grassland with scattered trees should be considered important habitat. Short-eared Owls exhibited a tendency for loose nesting aggregations in areas that were predominantly tall grasses, and often on grazed grassland. Fledging success was low and both anthropogenic and natural causes of mortality were identified. The findings of this study will contribute greatly to the current understanding of Short-eared Owl natural history, and the techniques described will be valuable tools for subsequent research and conservation initiatives.Au cours de la dernière moitié du siècle, la population du hibou des marais (Asio flammeus) a subi d'un déclin sévère à travers l'Amérique du Nord. Plusieurs aspects de leur histoire naturelle sont mal compris, entravant ainsi le développement de plans de gestion efficaces. Le but principal de cette thèse était d'essayer de combler le manque de notions à l'égard du hibou des marais tout en assurant une base pour les études ultérieures. Les objectifs spécifiques comportent trois volets: 1) examiner les origines spatiales à travers l'Amérique du Nord en lien avec les déplacements nomades, migratoires et/ou philopatriques; 2) développer un protocole pour les sondages visuels visant à améliorer les efforts de surveillance, et à faciliter l'évaluation de l'utilisation de l'habitat à travers les saisons à l'échelle du paysage; et 3) décrire des sites de nidification, le succès des nids et les causes d'échec de la nidification. L'analyse des isotopes stables était utilisée pour examiner les origines spatiales, et malgré son aspect exploratoire, cette méthode a démontrée que l'espèce pourrait posséder différentes stratégies de déplacement à travers l'Amérique du Nord. Le protocole mis en place pour les sondages visuels accomplis par des bénévoles fût un succès durant la période d'essai, et devrait être une méthode de surveillance sûre pour suivre l'abondance et la distribution de l'espèce à travers le temps. Sur la base d'une comparaison des sites 'utilisés' et 'disponibles' sur deux îles du Lac Ontario près de Kingston dans l'est de l'Ontario, l'importance du couvert forestier durant l'hiver semblent dépendre des effets climatiques saisonniers. Aussi, durant la saison de reproduction dans cette région, le pâturage avec les arbres épars doit être considérés comme l'habitat essentiel. Les hiboux des marais ont démontré une tendance pour les nids faiblement agrégés, dans des régions principalement constitués de hautes herbes et souvent dans les pâturages. Le succès d'envol était faible, et les causes de mortalité naturelles et anthropiques étaient identifiées. Les conclusions de cette étude vont contribuer énormément à la compréhension de l'histoire naturelle du hibou des marais, et les techniques décrites seront des outils de valeur pour la recherche et les efforts de conservation dans l'avenir.
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Whiteley, Jonathan. "Climate change and habitat fragmentation in a boreal forest bryosphere experiment". Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114398.
Testo completoAbstract (sommario):
Climate change encompasses not only global changes in temperature, but also changes in precipitation, variability, and large-scale shifts in conditions to higher latitudes and altitudes. Many species respond by following suitable environmental conditions to new locations, but the necessary dispersal may not be possible on landscapes fragmented by anthropogenic land-use. This non-additive interaction is poorly understood, particularly in the boreal forest, whose extensive circumpolar distribution and large pool of soil carbon have the potential to feedback to global climate. These forests take up atmospheric carbon through primary production, which is often limited by nitrogen, and release carbon through decomposition, which may be sensitive to changes in temperature, precipitation, or biotic communities. Nitrogen-fixing cyanobacteria in symbiotic association with feather mosses may reduce nitrogen-limitation, but the environmental and biotic factors controlling them have only recently begun to be explored.I used a two-year field experiment near the northern limit of the boreal forest in northern Quebec, Canada, to assess the impacts of habitat fragmentation and simulated climate change treatments on model moss ecosystems. I measured treatment effects on microarthropod and symbiotic cyanobacteria communities associated with the feather moss Pleurozium schreberi, as well as ecosystem processes of nitrogen-fixation, moss growth, and decomposition within the bryosphere (comprising the moss layer and associated biota). The experiment showed that N-fixation was positively affected by moisture conditions, but negatively affected by available nitrogen. N-fixation was only weakly related to cyanobacteria density, which was unaffected by experimental treatments. Moss growth stopped by the second year of drought, leading to net biomass loss, due to rates of decomposition exceeding moss productivity. Microarthropod abundance and richness also declined under drought conditions, but only in isolated patches, suggesting that dispersal is able to maintain populations in the face of environmental stress. This reveals the predicted synergistic effects of climate change and fragmentation: the combined effects are greater than the sum of individual effects. The results of this long-term field experiment highlight the overall importance of water availability in the bryosphere, and the strength of environmental controls on ecosystem processes, even in such a biodiverse system.Les changements climatiques incluent non-seulement les changements de température au niveau planétaire, mais également les changements au niveau des précipitations et variabilité, ainsi que le déplacement à grande échelle des conditions aux altitudes et latitudes élevées. Plusieurs espèces ont comme réaction à ces modifications de suivre les conditions environnementales plus propices à de nouvelles locations. Mais les déplacements nécessaires peuvent être impossibles sur des paysages divisés par l'utilisation anthropique des terres. Cette interaction non-additive demeure incomprise, particulièrement dans la forêt boréale dont sa répartition circumpolaire étendue et sa grande quantité de carbone dans le sol créent un potentiel de rétroaction au climat planétaire. Ces forêts absorbent le carbone atmosphérique par la production primaire, laquelle est souvent limitée par la disponibilité en azote. Elles relâchent également le carbone par un processus de décomposition, lequel est influencé par les changements de température, de précipitation et les communautés biotiques présentes. Les cyanobactéries fixatrices d'azote en symbiose avec les hypnes peuvent réduire les limites induites par l'azote. Cependant, les facteurs environnementaux et biotiques les contrôlant sont étudiés depuis peu.Afin d'examiner les effets de la fragmentation des habitats et des traitements simulés des changements climatiques sur des modèles d'écosystème de mousse, j'ai effectué une expérience de terrain d'une durée de deux ans, qui s'est déroulée près de la limite nordique de la forêt boréale au Québec. J'ai évalué la réponse des communautés de microarthropodes et de cyanobactéries symbiotiques, associées à Pleurozium schreberi, à ces traitements, ainsi que les processus écosystémiques de fixation de l'azote et la croissance et la décomposition à l'intérieur de la bryosphère (incluant la couche de mousse et le biote associé). L'expérience a démontré que la fixation de l'azote est positivement influencée par les conditions d'humidité, mais négativement influencée par la disponibilité de l'azote. La fixation de l'azote n'est que faiblement reliée à la densité et diversité des cyanobactéries, lesquelles n'ont pas été perturbées par les traitements expérimentaux. La croissance des mousses s'est arrêtée à la deuxième année de sécheresse, menant à une perte nette de biomasse causée par un taux de décomposition excédentaire à la production de mousse. L'abondance et la richesse des microarthropodes diminuent également sous des conditions de sécheresse, mais seulement à des endroits isolés. Cela suggère que la dispersion est apte à maintenir les populations même lors de stress environnementaux. Cela confirme également les effets synergiques prédits des changements climatiques et de la fragmentation des habitats : les effets combinés sont plus amples que la somme des effets individuels. Les résultats de cette expérience à long terme soulignent l'importance de la disponibilité de l'eau dans la bryosphère ainsi que l'influence des contrôles environnementaux sur les processus environnementaux, et cela même dans un environnement aussi diversifié.
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Wan, Ahmad Wan Juliana. "Habitat specialisation of tree species in a Malaysian tropical rain forest". Thesis, University of Aberdeen, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368534.
Testo completoAbstract (sommario):
This thesis investigates the relationship between spatial distribution of tropical trees and variation in edaphic factors, particularly soil nutrient supply, and tests the importance of interspecific differences in growth rates and foliar nutrient concentrations as determinants of habitat specialisation. The distribution of some tree species at Pasoh Forest Reserve, Peninsular Malaysia, was correlated with variation in soil properties, especially available P concentrations, on a 50 ha plot. Seeding relative growth rates were highest on the alluvial soils, which had higher available P than the shale-derived soils in the absence of nutrient addition. The effect of habitat variation (characterised in terms of their nutrient and water availability) on tree growth of 115 species was examined within and between species. Overall, differences in tree growth rates between habitats correspond to variation in the pattern of nutrient supply and not water availability. Despite significant differences in growth rates between habitat types for some of the species, the differences in tree growth were a poor indicator of habitat preferences of tree species as defined by bias in their spatial distribution. Foliar nutrient concentrations of habitat generalists and two kinds of habitat specialists (alluvial and non-alluvial specialists) were compared using phylogenetically controlled comparisons. Sign tests showed only one significant difference in mean foliar nutrient (N, P, K, Ca and Mg) concentrations between distribution categories. The distribution of the differences in foliar mg concentrations between habitat generalists and alluvial specialists was significant at P < 0.05 and suggested that Mg concentrations were significantly greater in the habitat generalists. These results suggest that foliar nutrient concentrations are unlikely to explain differences between species in their habitat associations with respect to soil types at Pasoh.
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Gill, Jennifer A. "Habitat choice and distribution of wintering pink-footed geese, Anser brachyrhynchus". Thesis, University of East Anglia, 1994. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308250.
Testo completo
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Vaughan, Nancy. "Partitioning of foraging habitat resources among bats (Chiroptera) in Great Britain". Thesis, University of Bristol, 1996. http://hdl.handle.net/1983/5dae8611-bacc-4ff5-a3dc-49f7e3d1131f.
Testo completo
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Åkerstedt, Lovisa. "Intraspecifik aggression mellan gräsänder (Anas platyrhynchos) i urbana och rurala habitat". Thesis, Karlstads universitet, Institutionen för miljö- och livsvetenskaper (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-84260.
Testo completoAbstract (sommario):
The continuing increase in urbanization is changing the natural habitats of wild animals. Some wildlife have colonized urban areas and are exposed to new stimuli to which they respond differently: some species adapt whereas others thrive. Living in such an environment can lead to increased stress and elevated aggression. The purpose of this study was to examine the intraspecific aggression among mallards (Anas platyrhynchos) in two habitats with different degree of urbanization. Field observations were performed on groups of mallards in urban and rural environments. I predicted that there would be more aggressive behavior among mallards in urban than in rural habitats, based on the hypothesis that increased stress in an urban environment results in elevated aggression. Aggression was defined as the number of attacks, which was classified as chases, nips, and threats. I observed on average more than three times as many attacks (chases, nips and threats) in urban as in rural habitats. In addition, more females relative to males in the groups resulted in more attacks. Wild birds are important to flora, fauna, and man. Because high aggression can affect the fitness of wild urban animals negatively through, for example, physical injuries and increased disease transmission during fights, it is important that humans intervene to prevent this.Den fortsatta ökande urbaniseringen förändrar vilda djurs naturliga habitat. Vissa vilda djur har koloniserat urbana områden och utsätts för nya stimuli som de responderar olika på: somliga arter anpassar sig medan andra frodas. Att leva i en sådan miljö kan leda till ökad stress och förhöjd aggression. Syftet med denna studie var att undersöka den intraspecifika aggressionen mellan gräsänder (Anas platyrhynchos) i två habitat med olika nivå av urbanisering. Fältobservationer genomfördes på grupper av gräsänder i urbana och rurala miljöer. Jag förväntade mig att det skulle förekomma fler utdelade attacker bland gräsänder i urbana än i rurala habitat, baserat på hypotesen att ökad stress i en urban miljö resulterar i förhöjd aggressivitet. Aggression definierades som antalet utdelade attacker, vilket klassificerades till jagningar, nyp och hot. Jag observerade i medel mer än tre gånger så många attacker (jagningar, nyp och hot) i urbana som i rurala habitat. Utöver detta resulterade fler honor relativt hanar i grupperna i fler attacker. Vilda fåglar är viktiga för flora, fauna och människa. Eftersom hög aggression kan påverka vilda urbana djurs fitness negativt genom till exempel fysiska skador och ökad sjukdomsöverföring vid strid, är det viktigt att människan ingriper för att förhindra detta.
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Dodd, Jane. "Topographic learning and memory in habitat selection by Lipophrys pholis L". Thesis, Bangor University, 1998. https://research.bangor.ac.uk/portal/en/theses/topographic-learning-and-memory-in-habitat-selection-by-lipophrys-pholis-l(65cf5889-e075-4b3b-a268-06e3484ce380).html.
Testo completoAbstract (sommario):
Experiments were carried out to test the ability of L. pholis to learn and remember the position of a food reward in a hierarchical maze during daily trials. This task was completed in 9 days in the presence of LegoTM landmarks. Learning did not take place in the presence of a white screen clue or in the absence of any obvious visual clues after 15 days. An attempt was made to identify the effect of a change in conditions on L. pholis who had already learned to successfully navigate the hierarchical maze, and to identify the clues utilised in learning, by altering the intra and extramaze clues. Geomagnetic, olfactory / gustatory and current direction clues were eliminated as the source of spatial information, as was the use of a cognitive map (Tolman 1948, O'Keefe & Nadel 1978). Rather, evidence suggested that the fish were learning a specific route through the hierarchical maze using the LegoTM towers as beacons, and as a prompt as to which direction to turn at important stages in the journey. This memory was retained for a period of at least 30 days. A hierarchy of clue use was suggested by the fact that the subjects used the direction of entry to the experimental arena, or the direction by which the experimenter left the arena just prior to a daily test, as a directional clue to the position of the reward box in the absence of Lego towers. These experiments suggested that in the wild L. pholis uses the position of local landmarks, such as rocks and clumps of algae, to direct movements towards feeding patches. A study of behaviour of L. pholis placed in a novel artificial habitat was also carried out. L. pholis moved along the edges of the objects placed in the arena, followed regularly used paths between refuges, and explored the arena from a series of "base" refuges. In the more active individuals, each refuge was investigated until the subject took up residence in a preferred refuge. This adopted shelter was often centrally placed and commanded a good view of a large area of the arena. Activity was concentrated in the more complex half of the arena and experienced fish directed their movement towards this area 24 hours after 6 hours exploration of the novel habitat. There was also evidence to suggest that certain individuals learned the position of a specific preferred refuge after the 6 hour exploratory period. Finally, the ability of L. pholis to remember the position of a refuge was tested in an artificial habitat under the influence of different clues. L. pholis learned the position of the refuge in the presence of an A4 sized black screen clue only. They responded to this clue by moving towards it and pressing themselves up against it while LegoTM towers and a white screen clue did not provoke such a response. L. pholis continued to respond to the black screen in this way even when it was moved to another location further from the refuge. After 12 days L. pholis learned to use the black screen as an indirect clue and navigate to the refuge directly without first touching it. These results suggested that when placed in a novel habitat the immediate reaction of L. pholis is to move quickly towards the first dark area they see. Later, they systematically explore all available shelters and choose a preferred one according to complexity of the surrounding habitat. With experience, they can use the position of objects around them to navigate quickly and efficiently to their preferred refuge or the nearest suitable refuge depending on the severity of the threat.
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Kirkpatrick, Jon. "Assessing and improving the efficacy of BREEAM in relation to ecology". Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/4514.
Testo completoAbstract (sommario):
The loss of ecological integrity as a result of urban spread and construction threatens the overall biodiversity of urban areas and prompts us to consider means of better including ecological biodiversity within development projects. The UK’s best practice tool for ensuring the integration of ecology into such projects is the Building Research Establishments Environmental Assessment Method (BREEAM). This thesis seeks to identify the efficacy of the current approach to ecological integration within BREEAM, and enable development to foster biodiversity and ecology more positively in the urban environment. Qualitative and quantitative research techniques were used to develop a new approach to the integration of ecology within an existing and nationally recognised model. This began by exploring the efficacy of and the main flaws in the present system by a survey of ecologists with experience of the BREEAM process. This led to a new approach to establishing the ecological value of urban ecology utilising a new calculation methodology, adapting the current scheme to focus on land use change as a result of urban land use planning and development. This new approach utilises habitat changes at its core to measure positive and negative change and indicate potential design solutions in land use planning within a development. The innovative methodology was tested using an in depth case study to review and discuss its effective application. The outcome was a new way to address the important variables of habitat integration and linkages maintaining ecological integrity and provision of ecosystem services. It is considered that the outlined approach of the new Land Use and Ecology section of BREEAM is suitable for integration into the next iteration in 2010, which will enable development to positively foster biodiversity and ecology in the urban environment.
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Cantero, Juan José. "Plant community diversity and habitat relationships in central Argentina grasslands /". Tartu : Tartu University Press, 1999. http://bibpurl.oclc.org/web/19977.
Testo completo