Orientador: Denise de Cerqueira Rossa-Feres / Coorientador: Christine Strüssmann / Banca: Camila Chiamenti Both / Banca: Michel Varajão Garey / Resumo: Uma das principais abordagens em Ecologia envolve compreender a estrutura das metacomunidades e esclarecer quais processos ambientais e espaciais são responsáveis por promove-las. O Pantanal constitui um sistema interessante para avaliar a estrutura de metacomunidades de anuros por apresentar períodos de alagamentos que conectam as poças facilitando a dispersão dos anuros. Neste cenário, foram amostradas 75 comunidades de girinos em três sub-regiões o que possibilitou determinar, em escala local (cada sub-região) e ampla (todas as sub-regiões), a estrutura das metacomunidades, a influência relativa dos processos ambientais e espaciais na estrutura das metacomunidades e a congruência dos resultados nas três sub-regiões. De maneira geral encontramos pouca influência de processos espaciais e ambientais estruturando as metacomunidades. A inundação parece facilitar a dispersão dos anuros, explicando a fraca influência de processos espaciais. Já o hábito reprodutivo generalista da maioria das espécies, por aumentar o sucesso de colonização de novos habitats, explica a fraca influência das características ambientais na estrutura das metacomunidades. As estruturas detectadas corroboraram os resultados da influência relativa dos processos ambientais e espaciais. Em escala ampla e em duas das sub-regiões amostradas e foram detectadas quasi-estruturas (Nhecolândia e escala ampla) e estrutura aleatória (Porto Murtinho) que corroboram o fraco efeito estruturador do ambiente detectado na análise de processos. Miranda-Abobral foi a única sub-região que apresentou estrutura aninhada, corroborando a força do gradiente ambiental nessa metacomunidade, evidenciada pela análise de processos na qual foi a única sub-região com componente ambiental significativo. Nós detectamos que padrões e processos similares, relacionados a fraca ou nula influência ambiental,... / Abstract: One of the main approaches in Ecology involves understanding the structure of metacommunities and clarifying the environmental and spatial processes responsible for it. The Pantanal floodplain is an interesting system for assessing anuran metacommunities structure because local periodic floods connect ponds and facilitate anuran dispersal. In this scenario, were sampled 75 tadpole metacommunities, in three sub-regions of the Pantanal, and evaluated in local (each subregion) and broad scale (all the subregions): the structure of the metacommunities, the relative influence of environmental and spatial processes and if the results are similar between the three subregions. In general, we find weak influence of spatial and environmental processes structuring the studied metacommunities. The flood seems to facilitate dispersal of the anurans, explaining the weak influence of spatial processes. By increasing the success in the colonization of new habitats, the generalist reproductive habits of most the species seem to explain the weak influence of the environmental features structuring the metacommunities. Structure types found here corroborated the results of the relative influence of the environmental and spatial process, reaffirming the complementarity of the methodologies. On broad scale and in two of the subregions sampled were detected quasi-structures (Nhecolândia and broad scale) and random structure (Porto Murtinho), supporting the weak structuring effect of the environment features in the process analysis. Miranda-Abobral was the only sub-region with a nested structure, confirming the strength of the environmental gradient in this metacommunity, as evidenced by the processes analysis in which was the only subregion with a significant environmental component. Miranda-Abobral was the only sub-region that did not present a quasi-structure but a nested structure instead and ... / Mestre

Este trabalho analisa aspectos, em diversas escalas temporais e espaciais, da estrutura e dinâmica da comunidade arbórea na Reserva da Cidade Universitária Armando de Salles Oliveira (CUASO) (23º33\' S, 46º43\' W), em São Paulo, SP. A partir dos dados obtidos são sugeridas ações de manejo para fins de conservação da comunidade arbórea no local. A Reserva é uma mancha de floresta secundária com cerca de 10 ha de área. O histórico (1930-1994) das modificações da paisagem no entorno (330 ha) da Reserva é descrito, e evidencia o processo de urbanização ocorrido no período, com conseqüente diminuição de área coberta por vegetação herbácea e aumento da área coberta por construções. As áreas florestadas sofreram declínio e posterior recuperação parcial. Cerca de 40% da Reserva tem vegetação com mais de 70 anos de idade, e 22% são áreas com menos de 27 anos de idade, localizadas próximo às bordas. Foi realizado o mapeamento, medição de DAP e identificação de todas as 1157 árvores com DAP &gt; 25 cm em 8,58 ha (Área 1, a área total da Reserva com exceção do lago e uma porção de 1,5 ha dominada por Eucalyptus sp.) e de todas as 1270 árvores com DAP &gt; 9,5 cm em 2 ha (Área 2) no interior da Reserva. Na Área 1 foram encontradas 91 espécies (10,9% exóticas) e índice de Shannon H\' = 3,34 nats/ind., com 33,7% das espécies sendo representadas por apenas um indivíduo. Espécies exóticas e nativas introduzidas estão, em geral, restritas às porções próximas à borda, com exceção de Archontophoenix cunninghamiana. Não existem áreas na Reserva a mais de 110 m de distância da borda, devido ao seu tamanho e formato. Análises de correspondência mostram variação importante na comunidade (DAP &gt; 25 cm) com a distância da borda até cerca de 50 m, mas sugerem maior importância da idade da vegetação na determinação da composição da comunidade. Na Área 2, foram encontradas 103 espécies (10,7% exóticas) e H\' = 3,54 nats/ind. Foram descritas as mudanças na estrutura e composição da comunidade arbórea (DAP &#8805; 15,9 cm) ocorridas entre 1992 e 1997 em uma área de 100 x 50 m no interior da Reserva. Densidade e área basal da comunidade total aumentaram consideravelmente no período; diversidade e equabilidade permaneceram praticamente as mesmas, mas diversidade e equabilidade de espécies nativas diminuíram. Entre as árvores com DAP &#8805; 9,5 cm, em uma área de 2,1 ha, A. cunninghamiana foi a espécie com maior densidade, com 305 indivíduos (22,5% do total). A espécie mostra preferência por estabelecimento em locais sombreados. A análise da estrutura de tamanhos indica um aumento futuro da densidade relativa da espécie. Dois levantamentos com 2,5 anos de intervalo (DAP &#8805; 9,5 cm) mostraram a morte de três dos 154 indivíduos iniciais e o recrutamento de mais 89, levando a um crescimento populacional de 19,4 %.ano-1, muito elevado. CUAKIA, um gap model derivado de KIAMBRAM, foi parametrizado para simular o estado atual da floresta na Reserva. O modelo previu uma fase sucessional inicial dominada por Piptadenia gonoacantha, seguida por uma fase de dominância de Croton floribundus e Alchornea spp. e, posteriormente, por Ficus insipida e outras espécies de dossel tolerantes à sombra e de grande longevidade. A distribuição espacial de árvores em múltiplas escalas espaciais foi analisada usando a função L (modificação de K de Ripley) e g uni e bivariada. O conjunto de indivíduos com DAP &gt; 25 cm apresentou distribuição regular em pequenas escalas (r < 6 m) e agregada em escalas maiores (17 m < r < 115 m). Quase todas as espécies analisadas apresentaram distribuição agregada em alguma escala espacial. Os resultados sugerem competição em pequena escala e limitação de dispersão de sementes como os principais fatores determinantes dos padrões encontrados. Os dados de mapeamento das árvores com DAP &gt; 25 cm foram usados para a divisão da Reserva em áreas de vegetação relativamente homogênea. Análise de correspondência foi usada como ferramenta de ordenação de parcelas circulares (r = 10 m) dispostas em uma grade regular com espaçamento de 10 m. Os valores de cada parcela foram mapeados e com base nestes mapeamentos foram definidas nove zonas de manejo no interior da Reserva. Uma das zonas é quase exclusivamente ocupada por Eucalyptus sp.. Outras apresentam predominância de espécies exóticas e/ou plantadas na Reserva. Sugere-se a introdução de espécies nativas e o controle de exóticas, especialmente A. cunninghamiana, no interior e no entorno da Reserva. / This work analyses the structure and dynamics, at several spatial and temporal scales, of the arboreal community in the Reserve of the Cidade Universitária Armando de Salles Oliveira (CUASO) (23º33\' S, 46º43\' W), São Paulo, SP. Based on these data, management actions are suggested, aiming at the conservation of the arboreal community at the site. The Reserve is a secondary forest patch with an area of approximately 10 ha. We describe the 1930-1994 changes in landscape structure in the surroundings (330 ha) of the Reserve, showing the urbanization process in the region. As a consequence, the area covered by grasslands was reduced and the area covered by buildings increased. Forested areas declined and recovered partially afterwards. Roughly 40% of the Reserve encompasses vegetation more than 70 years old and 22% are areas less than 27 years old, located near the edges. We mapped, measured the dbh and identified all 1157 trees with dbh &gt; 25 cm in 8.58 ha (Area 1, the total area of the Reserve excluding the lake and a 1.5 ha-area dominated by Eucalyptus sp.) and all 1270 trees with dbh &gt; 9.5 cm in 2 ha (Area 2) in the Reserve. In Area 1 we found 91 species (10.9% being exotic) and a Shannon index H\' of 3,34 nats/ind., with 33.7% of the species being represented by only one individual. Exotic species and introduced natives were generally restricted to the regions near the edge, with the exception of Archontophoenix cunninghamiana. No place inside the Reserve is more than 110 m away from the edge, due to the size and shape of the Reserve. Correspondence analyses showed important variation of the community (dbh &gt; 25 cm) with distance to the edge up to 50 m, but suggest that age of vegetation is more important in defining the composition of the community. In Area 2 we found 103 species (10.7% exotic) and H\' = 3.54 nats/ind. We analysed structural and compositional changes of the arboreal community (dbh &#8805; 15.9 cm) between 1992 and 1997 within a 100 x 50 m plot. Density and basal area of the total community increased considerably in the period; species diversity and evenness remained almost the same, but diversity and evenness of native species decreased. In a 2.1 ha area inside the Reserve, A. cunninghamiana was the species with the highest density among trees with DBH &#8805; 9.5 cm, with 305 individuals (22.5% of total). The species shows preference for establishment in shady sites. The size structure analysis indicates a future increase in the relative density of the species. Two surveys with a 2.5 years interval (DBH &#8805; 9.5 cm) showed the death of three of the initial 154 individuals and the recruitment of 89 more, leading to a population growth of 19.4 %.year-1, a very high rate. CUAKIA, a gap model derived from KIAMBRAM, was parameterized to simulate the present state of the forest in the Reserve The model predicted an initial sucessional phase dominated by Piptadenia gonoacantha, followed by a phase dominated by Croton floribundus and Alchornea spp. and, later, by Ficus insipida and other shade-tolerant and long-living canopy species. The spatial distribution of trees was analysed using the L (modification of Ripley\'s K) and g functions, in their univariate and bivariate forms. The total pool of individuals with dbh > 25 cm showed uniform distribution at small scales (r < 6 m) and clumped distribution at bigger scales (17 m < r < 115 m). Almost all species showed clumped distribution at some scale. The results suggest competition at small scales and seed dispersal limitation as the main determinants of the patterns found. The data from the mapping of trees with dbh &gt; 25 cm were used to divide the Reserve into areas covered with relatively homogeneous vegetation. Correspondence analysis was used to ordinate circular plots (r = 10 m) laid out on a regular 10 m-interval grid. Scores of each plot were mapped and this mapping was used to define nine management zones inside the Reserve. One of the zones is almost exclusively occupied by Eucalyptus sp.. Others are dominated by exotics or trees which were planted in the Reserve. We suggest the introduction of native species and the control of exotics, especially A. cunninghamiana, inside the Reserve and in its surroundings.

Orientadores: Vera Nisaka Solferini, Marlies Sazima / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T20:09:03Z (GMT). No. of bitstreams: 1 FernandezOtarola_Mauricio_D.pdf: 8414831 bytes, checksum: 9aabd91ed56ca9aadd06aa11ff07703c (MD5) Previous issue date: 2012 / Resumo: O resumo poderá ser visualizado no texto completo da tese digital / Abstract: The abstract is available with the full electronic document / Doutorado / Ecologia / Doutor em Ecologia

Mid-latitude shelf-seas are highly productive regions that host a rich diversity of animals including large numbers of marine mammals and seabirds. These large vertebrate predators play a crucial role in the functioning of shelf-sea ecosystems. However, the combined effects of multiple anthropogenic stressors are driving unprecedented declines in many of their populations. Mitigating this depends upon effective conservation and integrated ecosystem based approaches to management, which require a comprehensive understanding of the habitat needs of marine predators. The foraging efficiencies of marine predators are closely tied to the availability of a number of oceanographic features. As such, these physical habitats represent critical locations within a species’ range whose preservation and protection should be of high priority. The collection of studies presented in this thesis aims to improve our understanding of the physical oceanographic processes that underlie the at-sea behaviours and distributions of marine mammals and seabirds in coastal and shelf-sea environments. A combination of at-sea boat surveying, animal-borne biologging, satellite remote-sensing, passive acoustics and numerical modelling was used to collect information on the distributions and foraging behaviours of a range of marine predators alongside the bio-physical characteristics of the oceanographic habitats they occupied. These data were then used to (1) examine the use of oceanographic habitats generated around tidal-mixing fronts and coastal topographic structures by a range of piscivorous species including bottlenose dolphins Tursiops truncatus, common dolphins Delphinus delphis, harbour porpoises Phocoena phocoena and northern gannets Morus bassanus, and (2) identify the physical processes underlying their creation. Original aspects of this work include the examination of the fine-scale bio-physical mechanisms that link marine predators to tidal-mixing fronts and coastal tidal-topographic structures. Main findings indicate that offshore habitats around tidal-mixing fronts are used by both common dolphins and northern gannets for foraging. Individuals associated with patches of increased sub-surface primary productivity, which were generated via a bi-weekly cycle of episodic turbulent mixing and stratification following an adjustment in the spatial position of a front with the spring-neap cycle. Moreover, around fronts, the dives of gannets were likely to be short and of a V-shaped strategy (with little active swim phase), which likely reflects an increase in the accessibility and catchability of their prey. In a coastal estuarine system, bottlenose dolphins were shown to associate with predictable downwelling features generated during flood tidal flows that were thought to act as a foraging aid. Together, these findings highlight the fundamental role physical oceanographic processes play in the structuring of marine ecosystems by providing vulnerable marine predators with prosperous and reliable foraging resources that they can exploit. This work has implications for both future studies of marine predator foraging ecology and the management of anthropogenic activities in coastal and shelf-seas.

Globally the failure of traditional fisheries management approaches is evident through the increasing number of overexploited or depleted marine stocks. Past sectoral management has failed to address cumulative impacts of fisheries activities on ecosystem health. Ecosystem based approaches have been advocated as a viable alternative for sustainable management of marine ecosystems as they present a holistic and precautionary approach, which integrates management of multiple activities with that of maintaining ecological health. Although conceptually advanced, implementation has been poor due to the complexities of competing ecological and socio-economic management objectives. Marine spatial planning can facilitate the implementation of ecosystem based management as it is able to address the spatial heterogeneity of biological communities and anthropogenic activities. Ecosystem based management approaches aim to address the full range of anthropogenic drivers on the marine environment, including but not limited to fisheries, tourism, coastal development, and land and marine based pollution sources amongst others. Fisheries activities have a direct impact on the local marine environment and were therefore the focus of this study which forms a starting point for implementing ecosystem based management in Algoa Bay. It is envisaged that future research will build on this foundation and include additional anthropogenic drivers into the management and monitoring strategies developed in this study in order to achieve a truly holistic ecosystem approach to management in Algoa Bay. Algoa Bay is situated centrally within the warm-temperate Agulhas bioregion along the east coast of South Africa and is the largest and best formed logarithmic spiral bay along this section of coastline. A large city, two commercial ports and several coastal settlements are located within Algoa Bay and a wide range of marine based activities occur within the area. A large section of the coastline is proclaimed as a National Park yet only two small offshore marine areas are formally protected. The development of a large marine protected area (MPA) adjoining the terrestrial section was proposed in the mid-1990s but a lack of adequate spatial data with which to quantify the fishery costs and conservation benefits led to wide scale public opposition and halted the declaration process. The primary goal of this study was to obtain and analyse baseline data to understand spatial and temporal trends in the distribution and abundance of fish populations and fisheries activities in order to develop a spatial framework for marine conservation and management in a data limited situation using Algoa Bay, South Africa as a case study. Furthermore, it aims to contribute to the development of a monitoring framework to evaluate the success of implementation and the resultant changes in biological and socio-economic environments. This information will be used to re-initiate the stakeholder engagement process in the future.

No description available.

The conversion of natural habitat to urban areas has lasting impacts on wildlife and biodiversity. Known effects to urban wildlife include direct mortality while crossing roads, reduced species diversity, and habitat fragmentation and degradation. Among wildlife occupying urban areas, turtle populations can be particularly impacted in anthropogenic landscapes. Snapping Turtle (<i>Chelydra serpentina</i>) is one of the most common species found within urban wetlands, but populations are beginning to show declines in northern portions of their geographic range. The preservation and management of this species is aided by knowledge related to its spatial ecology. I investigated <i>C. serpentina</i> home range, movement, habitat use, and habitat selection in a midwestern USA urban wetland complex during two active seasons (May-August 2019 and 2020) using radiotelemetry. Home range sizes and movement did not differ between sex or sample year except the mean movement of males decreased from 2019 to 2020. No differences in mean monthly movement were found between sexes but mean monthly movement did differ between month and year. Habitat use was skewed during the active season and did not differ between sex or year, but there were positive habitat associations between forested wetlands and modal centers of activity (MCA). Habitat selection was tested at two spatial scales by comparing random points to home ranges and turtle locations using Euclidean Distance Analysis. Turtles appeared to select home ranges from available habitat site-wide but did not select habitat within home ranges. Home range selection included semi-permanent open water, trail, road/barrier, permanent open water, scrub-shrub, ditches, shoreline, and vegetated ponds, while upland forest, field and agriculture habitat were avoided. Home ranges appear to be constrained by available habitat and movement differences between years may be due to anthropogenic change in water levels. The use of space seems to be more affected by wetland size and connectivity than proximity to barriers, which suggests that management practices that protect turtles from accessing roads and railways will benefit populations. Additionally, habitat selection and association indicate that ditches are utilized as corridors between wetland areas. When feasible, increasing the connectivity of large wetlands containing many habitat types should have positive impacts on the persistence of populations in human dominated landscapes.

Great Basin bristlecone pine (Pinus longaeva D.K. Bailey) is a keystone species of the subalpine forest in the Great Basin and western Colorado Plateau ecoregions in Utah, Nevada, and California. Bristlecone pine is also the world's longest-lived non-clonal organism, with individuals occasionally reaching ages up to 5,000 years old. Because of its longevity, bristlecone pine contains an important proxy record of climate data in its growth rings. Despite its ecological and scientific importance, bristlecone pine's distribution and associated environmental drivers are poorly understood. Geospatial technologies, including unmanned aircraft systems (UAS), remote sensing, geographic information systems (GIS), and spatial modeling techniques can be used to quantify and characterize biotic and abiotic factors that constrain the fundamental and realized niches of bristlecone pine and other subalpine forest species. In Chapter 1, we describe workflows and important technical and logistical considerations for collecting aerial imagery in mountainous areas using small UAS, enabling high-quality remotely sensed datasets to be assembled to study the ecology of subalpine forests. In Chapter 2, we discuss a unique outlier population of bristlecone pine found in the Stansbury Mountains, Utah. We used GIS to delineate boundaries for five small stands of bristlecone pine and examined two competing hypotheses that could explain the species' presence in the range: 1) that the current population is a relict from the Pleistocene, or 2) that long-distance dispersal mechanisms led to bristlecone pine's migration from other mountain ranges during or after the warming period of the Pleistocene/Holocene transition. Potential migration routes and barriers to migration were considered in our effort to understand the dynamics behind the presence of this unique disjunct population of bristlecone pine. Chapter 3 describes a comprehensive mapping effort for bristlecone pine across its entire distribution. Using data from historic maps, vegetation surveys, herbarium records, and an online ecological database, we compiled nearly 500 individual map polygons in a public-facing online GIS database representing locations where bristlecone pine occurs. Using these occurrence data, we modeled the suitable habitat of the species with Maximum Entropy (MaxEnt), examining the relative importance of 60 environmental variables in constraining the species distribution. A probability map was generated for bristlecone pine, and the environmental variables were ranked in order of their predictive power in explaining the species distribution. We found that January mean dewpoint temperature and February precipitation explained over 80% of the species distribution according to the MaxEnt model, suggesting that the species favors drier air conditions and increased snowfall during winter months. These three studies demonstrate that geospatial tools can be effectively used to quantify and characterize the habitat of bristlecone pine, leading to improved management and conservation of the species in the face of multiple threats, including mountain pine beetle (MPB), white pine blister rust (WPBR), and possible habitat constriction due to climate change.

While range-wide population declines have prompted extensive research on greater sage-grouse (Centrocercus urophasianus), basic information about southern periphery populations, such as the Bald Hills population in southern Utah, has not been documented. The objective of this research was to determine habitat preferences and space use patterns of the Bald Hills sage-grouse population which occurs in an area of high potential for renewable energy development. I tracked 66 birds via VHF telemetry in 2011 and 2012 and surveyed vegetation plots throughout the study area. I found that the population was primarily one-stage migratory with seasonal distributions that did not correspond well with previously developed suitable habitat maps (based on local biologist knowledge and lek data) for all seasons; I also found that mean home range sizes ranged from 82 km2 to 157 km2. Nesting hens did not select for any measured vegetation characteristics within the study area, while brood-rearing hens selected for high forb cover. Birds at summer sites (non-reproductive bird locations during the summer season) selected for greater grass and forb cover and lower shrub cover compared with random sites. Overall, Bald Hills sage-grouse used areas with greater shrub canopy cover and lower grass and forb cover than recommended in habitat guidelines. Ten predictor variables were used to model suitable seasonal habitat using Maximum Entropy (maxent). All models were created for the Bald Hills population and projected to the Bureau of Land Management Cedar City Field Office management area and produced excellent model fit (AUC > 0.900). The Bald Hills population had similar nesting and winter habitat preferences as other populations but different brood-rearing and summer habitat preferences. I found local management techniques to be an important driver of seasonal habitat selection; birds selected for areas that had undergone habitat treatments (such as broadcast burn and crushing) within the previous 10 years. My results indicated the Bald Hills periphery population occupies marginal habitat and has adapted unique seasonal habitat preferences. Managers of isolated, fringe, and low-density populations should develop locally specific management guidelines to address the unique adaptations and ensure the persistence of these populations.

In this thesis we study two reaction-diffusion models that have been used to analyze the existence of alternate stable states in ecosystems. The first model describes the steady states of a logistic growth model with grazing in a spatially homogeneous ecosystem. It also describes the dynamics of the fish population with natural predation. The second model describes phosphorus cycling in stratified lakes. The same equation has also been used to describe the colonization of barren soils in drylands by vegetation. In this study we discuss the existence of multiple positive solutions, leading to the occurrence of S-shaped bifurcation curves. We were able to show that both the models have alternate stable states for certain ranges of parameter values. We also introduce a constant yield harvesting term to the first model and discuss the existence of positive solutions including the occurrence of a Sigma-shaped bifurcation curve in the case of a one-dimensional model. Again we were able to establish that for certain ranges of parameter values the model has alternate stable states. Thus we establish analytically that the above models are capable of describing the phenomena of alternate stable states in ecological systems. We prove our results by the method of sub-super solutions and quadrature method.