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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Determinants of Termite Species Taxonomic, Phylogenetic, and Functional Diversity in the Amazonian Forest

Dambros, Cristian de Sales 01 January 2015 (has links)
The distribution of species in space is determined by the species dispersal capacity, adaptation to environmental conditions, and response to predators and competitors. To determine the importance of dispersal limitation, environmental filtering, and species interactions on the distribution of species in the Brazilian Amazonian forest, I sampled termites in a large area of Brazil. I investigated patterns in species occurrence that could indicate competition and predation structuring termite communities, and analyzed the association of termite abundance and species richness with the density of ant predators. The spatial distribution of termites, and their association with climatic and edaphic conditions were also used to infer about the effects of dispersal limitation and environmental filtering. A total of 271 termite species and 4,389 colonies was found in the 148 transects sampled. Predator density was the strongest predictor of termite abundance and species richness at small spatial scales, but the turnover in termite species composition was mostly associated with measures of soil texture. At broad spatial scales, soil chemistry, climate, and isolation by distance were associated with termite abundance, species richness, and species composition. These results suggest that both species interactions, their association with the environment, and their dispersal capacity determine their distribution. Nevertheless, dispersal limitation seem to be stronger over large areas, whereas environmental filtering can act both at small and large geographic scales.
42

Análise da vegetação arbórea e conservação na Reserva Florestal da Cidade Universitária \"Armando de Salles Oliveira\", São Paulo, SP / Analysis of arboreal vegetation and conservation at the Forest Reserve of the Cidade Universitária \"Armando de Salles Oliveira\", São Paulo, SP, Brazil

Dislich, Ricardo 29 May 2002 (has links)
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.
43

Drivers of variation in the migration and foraging strategies of pelagic seabirds

Clay, Thomas Anthony January 2017 (has links)
The ability to move and forage efficiently plays a major role in determining the fate of individuals, and has important implications for population dynamics and ecosystem functioning. Migration is a particular type of movement strategy, whereby animals may travel remarkable distances in order to take advantage of seasonality in resource availability or to avoid arduous winter conditions; however, this can be at a cost in terms of increased mortality. Indeed, anthropogenic threats in non-breeding areas are a major cause of population declines and a better understanding of non-breeding spatial ecology is required in order to advance both ecological theory and conservation management. The recent development of animal tracking technologies, in particular light-based geolocation, has made it possible to track large-scale and long-term movements; however, there are still gaps in our knowledge, such as the links between migratory and reproductive performance, connectivity among populations and the ontogeny of migration strategies. In this thesis, I utilise multi-species and longitudinal datasets from albatrosses and petrels, some of the most mobile species on Earth, to explore the drivers of variation in movements, habitat use and foraging behaviour, and the implications for life history and conservation. In Chapter 1, I provide an overview of the key topics of this thesis. In Chapter 2, I provide quantitative recommendations of minimum sample sizes needed to track pelagic seabird migrations, using data from 10 species. In Chapter 3, I examine between- and within-population differences in the habitat preferences and distributions of albatrosses, including the relative roles of habitat specialization and intra-specific competition. In Chapter 4, I investigate the year-round movement and foraging strategies of petrels living in nutrient-poor environments. In Chapter 5, I examine potential links between foraging behaviour during the non-breeding season and reproductive senescence. In Chapter 6, I explore the ontogeny of foraging behaviour and foraging site fidelity in young albatrosses, shedding light on their “lost years” at sea. Finally, I conclude with a general discussion summarizing main findings and suggesting future work. Overall, my results highlight the complex relationships among individual traits, the environment, movements and foraging behaviour, and population dynamics across the lifespan of individuals, with implications for the conservation of this highly threatened group of species.
44

O tamanho de faixa ripária florestada influencia os padrões funcionais de peixes de riachos? /

Molina, Mariana Correia. January 2017 (has links)
Orientador: Lilian Casatti / Banca: Fabio de Oliveira Roque / Banca: Fábio Cop Ferreira / Resumo: As florestas ripárias são fundamentais para a manutenção da diversidade funcional de ambientes aquáticos. Elas apresentam relação direta com a entrada de materiais alóctones e disponibilidade de nichos nos riachos. Apesar do tamanho da floresta ripária provavelmente ser um fator determinante para as funções ecossistêmicas em riachos, ainda é necessário ampliar o conhecimento sobre como as configurações de largura de floresta ripária influenciam as comunidades aquáticas na região Neotropical. Nesse estudo, testamos se há relação da largura e da extensão da faixa ripária florestada e de variáveis locais (largura do canal, profundidade e velocidade) com os índices de diversidade e redundância funcional da ictiofauna. Para isso, utilizamos 43 trechos de riachos das bacias dos rios Paranapanema, Grande e Paraná, todos pertencentes à bacia do Alto Paraná. Para cada trecho de riacho nós obtivemos imagens de satélite referente ao ano de cada coleta e extraímos as larguras das faixas ripárias florestadas em duas escalas: 100 m (local), e 500 m. Baseado em dados de ecomorfologia, tamanho padrão, dieta, táticas alimentares e preferência por substrato, como atributos funcionais de 78 espécies, nós calculamos a distância média entre pares de espécies na comunidade (MPD), distância média entre uma espécie e seu táxon mais próximo (MNTD) e Redundância Funcional (FR). A composição de espécies entre as bacias foi testada por meio da Análise de Similaridade. Testamos a relação das variáveis... / Abstract: Riparian forests are essential to the maintenance of functional diversity in freshwater streams, since they are related to the input of allochthonous materials and niches availability. Thus, riparian forest size may be one important factor to ecosystem functioning on streams. However, it is still necessary to expand the knowlegde about how riparian forest widths influences acquatics systems in the Neotropical region. Our aim was to identify the relationship between width and extension of forested riparian strip along with local variables (channel width, depth and velocity) and functional diversity and redundancy of the ichthyofauna. To do this, we used 43 streams reaches from the Paranapanema, Grande and Paraná river basins, in the Alto Paraná basin. For each stream reach, we obtained satellite images and extracted the widths of the forested riparian buffer in two different scales: 100 m (local) and 500 m. Based on ecomorphology, standard length, diet, feeding tactics and substrate preference, as functional traits of 78 species, we calculated the mean pairwise distance (MPD), the mean nearest taxon distance (MNTD) and functional redundancy (FR). Species composition among basins was tested using Similarity Analysis. We tested the relationship between environmental variables (local and riparian strip) and functional diversity and redundancy using Generalized Additive Mixed Models. Our results indicated all three basins have a similar set of species probably due to a similar environmental filters and habitat homogenization. We also found less redundant communities in streams with greater width of riparian forest in the scale of 500 m, also associated to the smaller channel widths. Probably, these streams show a greater diversity of niches, and consequently higher occurrence of functionally distinct species. The present study demonstrated that greater riparian forested width led to ... / Mestre
45

Cultural and ecological relationships among consumers, food, and landscapes; implications for stewarding bear-human-salmon systems

Adams, Megan Sara 02 May 2019 (has links)
Human activity modifies the behaviour of large vertebrates and their acquisition of key resources. Despite the predation risk and competition for similar food resources that humans impose, wildlife consumers must acquire key foods across the landscape. Predation risk can modify foraging behaviour, yet we know little about the potential consequences, especially on large spatial scales. Humans may also affect food availability for wildlife by competing for shared prey, which most current harvest prescriptions fail to recognize. Against this background of threats to consumer-resource interactions, my research employed new conceptual, analytical, and practical approaches to seek not only new generalizable insight but also applied solutions. Addressing these goals, I characterized foraging behaviour by grizzly bears (Ursus arctos horribilis) on a focal prey, Pacific salmon (Oncorhynchus spp.), at multiple spatial scales. I predicted how human activity – both as modifications to landscapes and as salmon harvest – might affect bear-salmon interactions. I co-conceived, designed, and carried out this work through a framework of community engagement, which I crafted in collaboration with Indigenous communities in coastal British Columbia (BC). The framework (Chapter 2) identifies how scientists and communities can engage throughout the research process to work towards shared priorities, despite potential challenges in differences of knowledge systems or capacities. Methodologically, I used ratios of stable carbon (δ13C) and nitrogen (δ15N) isotopes in bear hair to estimate relative contributions of salmon in the annual diet of bears and employed existing data on landscape modification and salmon fisheries (i.e., escapement and catch) to characterize human activity and to measure associated variation in salmon consumption by bears. My first empirical contribution (Chapter 3) characterized spatial patterns of annual salmon consumption by grizzly bears across BC. I found substantial differences in salmon consumption within and among grizzly and black (U. americanus) bears in a large coastal region and across BC. Visualizing variation in consumer-resource interactions could guide conservation and management efforts that seek to protect predator-prey associations and marine subsidies for terrestrial ecosystems. I also investigated potential drivers of salmon consumption by bears in interior and coastal watersheds that varied in disturbance (Chapter 4). I found that human footprint in riparian areas of salmon-bearing watersheds affected bear diets more than the amount of salmon biomass available, showing that human activity can disrupt an otherwise strong predator-prey association. My community-based research occurred at the scale of a single large watershed, where I demonstrated how the Wuikinuxv First Nation might design their salmon management prescriptions according to their cultural values (Chapter 5). Despite a reduced abundance of salmon in the area, I identified harvest options that would trade-off benefits to local people and bears equally. In general, my dissertation research contributes to our understanding of the role humans increasingly play in mediating consumer-resource interactions. I also highlight how scientific research can support the leadership that local management can provide in mitigating human impacts to sustain an iconic predator-prey interaction of ecological, economic, and cultural importance. / Graduate / 2020-04-23
46

Spatial Ecology of Hawksbill Turtles (Eretmochelys imbricata) Nesting at Gandoca-Manzanillo National Wildlife Refuge, Costa Rica

Quintin D Bergman (6853298) 16 October 2019 (has links)
The beaches in the Gandoca-Manzanillo National Wildlife Refuge (GMNWR) in southeastern Costa Rica are known to host nesting critically endangered hawksbill sea turtles (<i>Eretmochelys imbricata</i>). The spatial ecology and movement behaviors of this nesting population has never been observed. Evaluating the spatial ecology of nesting sea turtles allows for a better understanding of their local movement behavior as well as their large scale oceanic movements that inform conservation needs. Satellite tracks reveal internesting, postnesting migration, and foraging behaviors for four nesting hawksbills from the GMNWR. During the internesting behavior, satellite-tracked hawksbills remained in the coastal waters near the nesting beach for 15 to 55 days before making their postnesting migration. Home-range areas occupied by internesting hawksbills vary between 21.9 and 557.9 km<sup>2</sup>. Hawksbill internesting high use areas overlapped with the marine boundary of the GMNWR for an average of 29% of time spent inside the refuge. The beginning of all four turtle’s migrations start with a pelagic circular movement away from the coast into the Caribbean Sea before resuming a northern coastal migration pattern. Migration routes varied in length from 662 to 1,486 km and passed through three or four exclusive economic zones of various neighboring nations. Foraging areas of three hawksbills were situated east of Nicaragua and one was found along the northern coast of Honduras, near Roatan. Foraging home-range areas of satellite-tracked hawksbills varied from 205.1 to 696.1 km<sup>2</sup>. This is the second satellite telemetry study completed on nesting hawksbills in the Costa Rican Caribbean and the first for GMNWR. These results display the use of pelagic and coastal migratory routes for the critically endangered hawksbill. Distant foraging grounds utilized by hawksbills nesting in Costa Rica reveal the importance for the preservation of the Miskito Cays and nearby ecosystems.
47

Integrating Black Bear Behavior, Spatial Ecology, and Population Dynamics in a Human-Dominated Landscape: Implications for Management

Raithel, Jarod D. 01 August 2017 (has links)
The New Jersey Division of Fish and Wildlife (NJDFW), in collaboration with Bear Trust International, presented us an opportunity to examine a long-term (33 years) American black bear (Ursus americanus) data set from northwestern New Jersey (NJ), USA. State agencies continue to grapple with uncertainty about the efficacy of socially divisive management actions such as recreational harvest and lethal control as tools to reduce escalating human-bear conflicts. We applied multistate capture-reencounter models to a large sample of black bear captures (>5,000) and dead recoveries (>1,300) between 1981 – 2014 to estimate cause-specific mortality and spatial dynamics between wildland and anthropogenic habitats. Additionally, we assessed temporal correlations between more than 26,500 reported human–black bear interactions and mortality rates. Adult females were twice as likely (0.163 ± 0.014) as males (0.087 ± 0.012) to be harvested, and cubs (0.444 ± 0.025) and yearlings (0.372 ± 0.022) had a high probability of dying, primarily from vehicle strikes. Nuisance behaviors reported declined with increasing harvest and lethal management (P = 0.028, R2 = 0.338). Adult bears previously designated as a nuisance and/or threat (hereafter, “problem”) were more likely to be harvested (0.176 ± 0.025) than those with no conflict history (0.109 ± 0.010). Combined legal kills and vehicle strikes, the two greatest mortality causes for marked bears, occurred significantly less than expected per unit area in urban and agricultural areas, and more than expected in the wildland-urban interface and wildland habitats. Across all age-classes, problem bears were significantly more likely to transition to anthropogenic habitats, yet they died at lower rates than conspecifics with no history of conflict in wildlands. Cubs and yearlings died at significantly higher rates than adults in the risky interface habitat, corroborating independent estimates of their increased susceptibility to harvest and vehicle strikes. Ultimately, wildland habitats represented a population source (λ = 1.133) and anthropogenic habitats a sink (λ = 0.945). Harvest represents an important management tool to help meet population targets and decrease human-bear conflicts by disproportionately removing problem bears.
48

Spatial and Feeding Ecology of the Fer-de-Lance (Bothrops asper) in Costa Rica

Wasko, Dennis Keith 14 April 2009 (has links)
Understanding the ways in which animals utilize space and obtain food are central themes in modern ecology. Formulating broad principles and elucidating the factors explaining such patterns are limited, however, by the availability of data from a broad range of species and systems. This problem especially true of snakes, a predator group about which even the most basic natural history data are often entirely lacking, even among abundant, widespread, and ecologically-important species. I studied the natural history and ecosystem role of one such species, the fer-de-lance (Bothrops asper) in lowland rainforest in Costa Rica. B. asper is a large, cryptic pitviper that is highly abundant in many Central American ecosystems and is strongly relevant to human health due to high incidence of snakebite, yet its biology under natural conditions is almost entirely undocumented. I used radiotelemetry to quantify home range, movement patterns, habitat usage, and foraging behavior. B. asper was found to have smaller home ranges and reduced movement patterns than similarly-sized temperate pitvipers, likely due to a greater reliance upon ambush foraging in patches of high prey density. Snakes also demonstrated strong selection for swamp habitat, which may reflect efforts to exploit frogs as a primary food source due to low availability of small mammals at the study site. I subsequently addressed the trophic status of this B. asper population using a supplemental-feeding experiment. In comparison to control snakes, individuals receiving supplemental food had smaller home ranges, shorter and less frequent movements, increased mass acquisition, and shifted to primarily forest rather than swamp habitat. These results support the suggestion that B. asper at the study site are strongly food-limited. Finally, I tested the hypothesis that fer-de-lance mediate local seed-predation rates by influencing habitat usage and foraging behavior of rodents. A series of behavioral experiments conflicted with many existing studies in failing to support this idea, as three rodent species demonstrated little snake avoidance, and none of likely ecological relevance. Collectively, this dissertation represents the first comprehensive field study of Bothrops asper and is among the first for any tropical snake, and suggests several avenues for future research.
49

The Influence of Roads on the Florida Panther

Schwab, Autumn C. 03 April 2006 (has links)
The Florida panther (Puma concolor coryi) is a relatively well studied species, but some aspects of its habitat requirements remain poorly understood. While it has been well established that the most important threat to panthers include limited habitat area and continued habitat loss and fragmentation, the importance of roads in this context has not been determined. The goal of this research is to determine the influence of roads on the movement patterns of the Florida panther. Panther telemetry data from 1981 until 2003 was used, as well as detailed road networks and vegetation maps. The influence of roads on individual panthers was determined through an analysis of: 1) vehicular mortality; 2) road crossing behavior; 3) road barrier effects; and 4) effectiveness of preventative measures. Results indicate that vehicle collisions continue to be a major threat to the Florida panther population, specifically adult males. Major roads form more of a barrier to movement than minor roads, but females are affected more than males. The combination of wildlife underpasses and high right-of-way fencing on I-75 has been extremely effective at vehicular mortality prevention, but the roadway remains a major barrier, particularly for female panthers. This has essentially segregated the movement of the sexes and has fragmented not only the limited habitat of the Florida panther, but also segments of the adult population critical to the propagation of the species.
50

Ethnobiology and population ecology of neotropical palms

Choo, Juanita Poh Sung 02 February 2011 (has links)
Palms are ecologically important and charismatic trees of the tropics. They are important to the livelihood of local communities and are key resources for the frugivore community in tropical forests. These frugivores are in turn hunted by humans for food. This ecological connection between human, palms, and frugivores provides a unique setting to study how cultural and ecological components within this multitrophic interaction influences palm populations. In chapter 1, I explored the traditional and ecological knowledge behind the cultivation of palm-weevil larvae for food. I found the Joti people, cultivated two species of weevil-larvae differently, which also determined whether palms were logged before or after reproductive maturity. The cultivation of each weevil-larvae species therefore had a differential impact on palm populations. In chapter 2, I investigated how frugivores mediate interactions between two dominant and co-occuring palms in the Peruvian Amazonia-- Attalea phalerata and Astrocaryum murumuru. I found frugivores codispersed seeds of the two palm species, which contributed to aggregated spatial patterns of their juveniles. Spatial patterns suggested associations between heterospecific palms experienced lower density-dependent mortality than associations between conspecifics and this likely contributes to the coexistence of the two palm species in their early life-history. These findings highlight the importance of dispersers to species coexistence and suggest over-hunting can lead to shifts away from species codominance. In chapter 3, I examined the contribution of dispersal, distance-and density-dependent to spatial ecology of Attalea phalerata. Using microsatellite-based parentage analysis, I found high levels of seed movement mediated by frugivore dispersers. Despite this, I found dispersal limitation remains strong enough to cause spatial aggregation between offspring and parents. As individuals grew towards maturity, distance and density dependent mortality contributed to increasingly disaggregated patterns between older offspring cohorts of parents, non-parent adults, and siblings. These results provide a foundation for assessing the impacts of hunting on the spatial ecology of palm populations. In chapter 4, we characterized 14 microsatellite loci for A. phalerata that were used in the parentage analysis of chapter 3. These loci amplified reliably and were sufficiently polymorphic and will be useful for future studies addressing population-level questions for this species. / text

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