This thesis consists of three sections, all of which are linked to the ecology of infectious disease and the decline of amphibians caused by chytridiomycosis. This thesis represents a detailed analysis of factors that allow the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), to persist in the Peruvian Andes. Collectively, these three sections elaborate on the current knowledge of the disease, how it persists in an area, as well as recommendations for future disease mitigation. Chapter one is a review of environmental and biological factors that contribute to the persistence of Bd. Here we address the use of biotic and abiotic reservoirs by the pathogen that allow Bd to persist. Biological reservoirs include both amphibian and non-amphibian hosts, thus allowing Bd to persist and proliferate when susceptible host densities recover. More than 40% of all amphibian populations are in decline and more than a third are at risk of extinction making it important to develop conservation measures for endangered and diminishing biodiversity. By understanding disease dynamics between reservoirs and other susceptible hosts, mitigation strategies can be developed to save amphibian populations from loss of genetic diversity or extinction. Chapter two addresses the current distribution and disease status of Bd in the Kosñipata Valley in southeastern Peru. We investigated the post-epizootic distribution and prevalence of Bd by examining trends in Bd prevalence across multiple sample periods. We modeled infection prevalence using logistic regression as a function of species, sample period, reproductive mode, life stage, and elevation and their two-way interactions. The most parsimonious model of prevalence contained two-way interactions between sample period and elevation, and reproductive mode and life stage. Overall we observed that prevalence varied over time; prevalence was higher in 2012-2015 than it was in 2008-2009. The interaction between elevation and sample period revealed that while prevalence decreased with elevation during the wet season, it generally increased with elevation during the dry season. We concluded that the prevalence of Bd in the Kosñipata Valley appears to have stabilized over time, indicating enzootic Bd. Long-term monitoring of infection in hosts is important because temporal patterns in prevalence and infection intensity are associated with changes in population abundance which could lead to future changes in the disease state. Chapter three examines Hypsiboas gladiator as a proposed reservoir species for Bd. We conducted field surveys to determined prevalence and calculated Bd loads across life stages, and calculated zoospore shedding rates of H. gladiator and sympatric species. Results showed that H. gladiator had the highest prevalence and Bd load, followed by Pristimantis toftae and then P. platydactylus. We tried to determine if prevalence and Bd load varied with distance from streams but found no direct evidence to support our claims. We also conducted susceptibility trials of H. gladiator to Bd. Results from our susceptibility trials are inconclusive. Shedding rates were higher in 2014 than 2013 for all species and varied by year. At this time we cannot determine if H. gladiator is a reservoir species for Bd.

Trophic interactions within aquatic ecosystems are complex, with many different pathways facilitating transfer of energy and nutrients among trophic levels and many different mechanisms that influence energy and nutrient transfer. This is illustrated in the “top down” and “bottom up” regulatory effects on aquatic food webs, through which primary producer biomass and, therefore, herbivore and carnivore densities, are influenced by both nutrient availability (bottom up) and densities of consumers at higher trophic levels (top down). In an aquatic food web, planktivore presence can directly alter zooplankton density via consumption, while indirectly shaping phytoplankton biomass via reduced herbivore abundance and the release of nutrients due to excretion, egestion, and decomposition. Novel species introduced into an established food web may have important consequences. An invasive species may impact an invaded food web through competition, predation, alteration of nutrient cycling, or, potentially, through facilitation of native species or other invasives. For example, an invasive planktivore may shift zooplankton density or community composition, thereby facilitating phytoplankton blooms. Such a planktivore may also compete with and, potentially, replace native species. Moreover, an invasive species that reaches high densities within its invaded range may serve as an important nutrient sink as it consumes a high biomass of native species or a nutrient source via excretion or decomposition. Two such invasive species with the capacity to dramatically alter native food web dynamics are bighead (Hypophthalmichthys nobilis) and silver carp (H. molitrix; collectively, bigheaded carp). Bigheaded carp are large-bodied, planktivorous fishes that were introduced into the United States in the 1970s and have since spread throughout much of the Mississippi River and its tributaries. These species currently threaten the Great Lakes, where they may constitute a threat to native planktivores such as gizzard shad (Dorosoma cepedianum) and commercially important species such as walleye (Sander vitreus), although there remains a great deal of uncertainty surrounding their potential ecosystem impacts. Consumption of both zooplankton and phytoplankton has been observed in bigheaded carp, although their impact on primary producer biomass is not well understood. Although field observations suggest that condition and abundance of native planktivores, including gizzard shad and bigmouth buffalo (Ictiobus cyprinellus), as well as zooplankton density, have declined following the bigheaded carp invasion, there is little direct, experimental evidence of bigheaded carp food web impacts. Therefore, I sought to examine the effects of bigheaded carp on native ecosystems through a series of mesocosm experiments at the Southern Illinois University pond facility. My primary objectives were to 1) observe potential competition between bigheaded carp and the native gizzard shad, 2) evaluate effects of bigheaded carp predation on zooplankton and phytoplankton communities, 3) assess impacts of bigheaded carp decomposition on nitrogen and phosphorus availability, and 4) measure the rate at which bigheaded carp excrete nitrogen and phosphorus. In order to elucidate the impacts of bigheaded carp on gizzard shad growth and survival, zooplankton and phytoplankton densities, and nitrogen and phosphorus availability in the pelagic and benthic pools and to determine whether gizzard shad experience a diet shift in response to bigheaded carp presence, I performed two mesocosm experiments with three treatments: gizzard shad only, gizzard shad, bigheaded carp, and fishless control (Chapter 1). I predicted that bigheaded carp would reduce zooplankton densities but that gizzard shad, which are both detritivorous and planktivorous, would be unaffected due to their ability to use detritus as an alternative food source. Additionally, both predator release via zooplankton consumption and increased nutrient availability from bigheaded carp excretion would stimulate phytoplankton. I found that gizzard shad survival was reduced by bigheaded carp presence but that surviving gizzard shad did not experience a decline in growth in the bigheaded carp plus gizzard shad treatments. This may have been due to the ability of gizzard shad to consume detritus, as foreguts of sampled gizzard shad in Experiment 2 contained mostly detritus. Moreover, phytoplankton density declined in the presence of silver carp in Experiment 2, suggesting silver carp herbivory. In addition, nitrogen and phosphorus availability in either the pelagic or benthic pools did not appear to be impacted by bigheaded carp presence. After demonstrating experimentally the overall negative impact of bigheaded planktivory on native food webs, I focused my remaining two chapters on the effects of silver carp on nutrient availability. In Chapter 2, I outline a decomposition experiment testing for potential changes in pelagic and benthic nitrogen and phosphorus availability and, in turn, phytoplankton, zooplankton, and macroinvertebrate densities in response to silver carp decomposition. Although silver carp die offs have been reported throughout the Midwest, little is known about the magnitude of those die offs and their consequences for the ecosystem. In this study, silver carp decomposition did not appear to alter nutrient availability or densities of phytoplankton or invertebrates. However, in comparison to northern streams in which salmon spawning and decomposition provide an important nutrient subsidy, the mesocosms used in this study have relatively higher background nutrient concentrations. Thus, silver carp decomposition, at least at the densities studied, may have little importance to in-stream nutrient availability. Lastly, because I am interested in how bigheaded carp, particularly silver carp, alter nutrient dynamics in invaded food webs, it is necessary to calculate silver carp nitrogen and phosphorus excretion rates, as well as body nitrogen and phosphorus content (Chapter 3). Nutrient stoichiometry theory predicts a balance between the relative consumption of nutrients by an organism and the extent to which the organism retains nutrients in its tissues or excretes them. Thus, it is a useful tool in determining how an invasive species may alter nutrient availability via consumption and excretion. In Chapter 3, I describe the body and excretion N:P ratios for silver carp, which exhibit a lower body N:P ratio than excretion N:P, suggesting that these organisms may serve as a sink for phosphorus. Moreover, silver carp body excretion N:P ratios were higher than those reported for gizzard shad, suggesting that, in regions where silver carp may replace gizzard shad or lower gizzard shad population density via competition (Chapter 1), silver carp may alter nutrient cycling processes in aquatic ecosystems by shifting the overall available N:P ratio. Bigheaded carp may pose a significant threat to invaded ecosystems through their potential to compete with native species, reduce plankton densities, and alter nutrient availability. However, although bigheaded carp are expanding in range and approaching the Great Lakes, the full extent of their ecosystem impacts remain uncertain. Through my work on bigheaded carp food web impacts, particularly the influence of silver carp on native species and nutrient cycling processes, I have found that bigheaded carp have the capacity to negatively impact invaded ecosystems overall by reducing zooplankton, phytoplankton, and forage fish densities. Moreover, as bigheaded carp in particular continue to reach high densities as they expand in range, their capacity to alter relative nitrogen and phosphorus availabilities must be monitored to understand the extent of their influence. Due to their ability to disrupt top down and bottom up processes in freshwater ecosystems, bigheaded carp constitute a critical environmental issue in the Great Lakes area and throughout the Midwest and, thus, it is imperative to continue to experimentally assess how bigheaded carp interact with native species to the detriment or benefit of U.S. freshwater communities.

Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv & Cons Biol) / Gaps in our knowledge of the functional roles of snakes within ecosystems limit our ability to predict the potentially cascading effects their removal from an ecosystem might create. Extirpation of snake species could potentially result in losses of ecosystem functionality if those taxa are ecologically unique. I used pitfall and funnel trap arrays, artificial cover object surveys, active searching, and passive camera trapping, as well as pre-existing faunal diversity data to identify terrestrial tetrapod species within the Koeberg Private Nature Reserve. This resulted in a list of 265 species, of which 13 were snakes. I then gathered data on dietary and four additional functional traits for each species from the literature. Next, using hierarchical and partitioning around medoids clustering, I identified ten broad dietary guilds and 54 functional guilds within the terrestrial tetrapod community. Of the dietary guilds Dasypeltis scabra was the only snake species that formed a unique single species guild and was one of four snake species (Pseudaspis cana, Homoroselaps lacteus and Lamprophis guttatus) to form four unique single species functional guilds. The remaining snakes clustered together within groups of other vertebrate predators. Functional diversity analysis was then used to simulate losing eight major taxonomic groups (birds, passerines, non-passerines, mammals, reptiles, snakes, non-snake reptiles and amphibians) and gauge the effects of those losses on overall community dietary and functional diversity. Functional diversity analysis revealed that the loss of certain snake species resulted in disproportionate losses of overall community dietary and functional diversity while losing others had negligible effects. These findings provide ambivalent support for the dietary and functional uniqueness of snakes suggesting that certain snake species are fulfilling unique functional roles within the ecosystem. Additionally, it is likely that losing those non-redundant species would result in significant losses of ecosystem functionality.

Conservation of biodiversity and sustainable resource use are central aims within ecology. This thesis focuses on the current data and environmental frameworks used to support these aims across different states in Europe. In particular, it examines the impact of geo-political boundaries on data-use, funding and planning for temporal movement of species in response to climate change. It also examines the current environmental framework agreements in Europe and their capacity to deal with trans-boundary aspects of biodiversity change. Through examination of European biodiversity datasets, undertaking species distribution modelling of forest taxa, examining economic data, palaeo-ecological data, and assessing international environmental framework agreements, this thesis identifies a number of important knowledge gaps. Probably unsurprisingly, the distribution of biodiversity in Europe mostly does not match political entities, all of which have individual aims, financial resources, and biodiversity management regimes in place. All have a significant impact on biodiversity conservation planning because i) the use of geo-politically truncated data influences modelling predictions, ii) financial commitment to biodiversity conservation varies between countries influencing success outcomes, iii) biodiversity persistence in current and future climate change does not recognise geo-political boundaries, and iv) many of the key environmental frameworks are implemented within countries and do not considering trans-boundary issues. Overall these findings significantly improve the understanding of conservation and resource management in Europe and fill a number of important knowledge gaps. They highlight the importance of appropriate trans-boundary ecological datasets and the need for more consistency across Europe in financial resources for biodiversity conservation. They also highlight the need for appreciation of areas of high-persistent biodiversity regardless of geo-political boundaries and environmental framework agreements that support cross-border conservation measures.

Made available in DSpace on 2014-06-11T19:32:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-14Bitstream added on 2014-06-13T21:03:47Z : No. of bitstreams: 1 luccajr_m_dr_sjrp.pdf: 333115 bytes, checksum: 8f050df82ed0c282a0a7af016f5f9cba (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / As espécies de Drosophila pertencentes ao cluster buzzatii se distribuem pelo território sul americano, na área compreendida desde a Amazônia brasileira até o chaco argentino. São espécies tipicamente cactofílicas, por utilizarem cladódios de cactos em decomposição para realizarem seu ciclo de vida. Neste trabalho investigamos as relações filogenéticas entre as seguintes espécies pertencentes ao cluster buzzatii: D. richardson (cluster stalkeri), D. koepferae (linhagem B26D2), D. seriema (linhagens D54M e D40F1M), D. serido (linhagens 1431.3 e H49F1M) e D. borborema (linhagem 1282.2). Dentre as 690 posições analisadas, foram encontrados 152 sítios conservados e 173 sítios informativos para parcimônia quando todas as seqüências foram alinhadas. O número médio total de nucleotídeos obtido para alinhamento foi de 493.4, sendo que nestes foi encontrada uma porcentagem superior no conteúdo de A-T, cerca de ~70%, em relação ao conteúdo de G-C, cerca de ~30%. Os métodos da máxima parcimônia e de distância foram utilizados para o estabelecimento das relações filogenéticas entre as seqüências analisadas e demonstraram topologias semelhantes. Nossos resultados mostram que as espécies analisadas do cluster buzzatii constituem um grupo monofilético, e que D. richardsoni (cluster stalkeri) apresenta-se como uma espécie irmã colocada Resumo em uma posição basal em relação às outras espécies. Ainda com base em nossos resultados verificamos que a análise das seqüências do espaçador intergênico ITS-1 forneceu relações filogenéticas resolvidas, sem quaisquer politomias, embora o grupo de espécies analisadas seja constituído por espécies com baixa divergência genética. / Drosophila species belonging to cluster buzzatii are cactophilic species found in South América with a distribution from Amazonian region until Argentina. In this work we investigate the phylogenetic relationship among four species of the cluster buzzatii: D. koepferae (linhagem B26D2), D. seriema (linhagens D54M e D40F1M), D. serido (linhagens 1431.3 e H49F1M) e D. borborema (linhagem 1282.2) as well as D. richardsoni (stalkeri cluster), analised as outgroup species by comparison of intergenic ITS-1 sequences of ribosomal DNA. This spacer sequences presented a length of ~550 bp in all of analysed species. It was not found any restriction site for Eco RI, Alu I, Hind III, Sal I e Hae III inside ITS-1 amplified fragments, indicating a similarity among them. Higher proportion of A-T content (~70%) was found for all analysed ITS-1 fragments, as expected for non-coding sequences. In respect to phylogenetic relation among species belonging to cluster buzzatii our data suggest that this cluster is monophyletic. However, was observed that D. serido lineages presented polymorphism higher than other species.

Made available in DSpace on 2014-06-11T19:32:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T20:23:29Z : No. of bitstreams: 1 oliveira_rm_dr_rcla.pdf: 1994469 bytes, checksum: a12e2b3f62e07832ede728e5eac3c53f (MD5) / O presente trabalho estuda a distribuição geográfica das espécies arbóreas que ocorrem nas Matas Ombrófilas da Costa Atlântica Brasileira, a partir da avaliação da interferência dos fatores ambientais. As espécies arbóreas foram compiladas a partir de levantamentos florísticos e fitossociológicos utilizando-se as bases cartográficas do Projeto RADAMBRASIL. Os dados climáticos foram obtidos a partir dos Projetos RADAMBRASIL e INMET. Foi realizado o mapeamento e a análise da distribuição das espécies arbóreas, dos fatores climáticos, geomorfológicos e da vegetação utilizando-se Sistema de Informação Geográfica (software SPRING 3.6 e IDRISI 32). A partir da sobreposição dos mapas temáticos, foram feitas análises de regressão linear simples e múltipla visando testar o índice de correlação dos dados cruzados em SIG (índice V CRAMERþS). Também foram realizadas análises fatoriais de correspondência. As análises estatísticas dos dados de distribuição geográfica das espécies cruzadas com os dados das variáveis ambientais apresentaram alta correlação, destacando-se insolação (hs) e médias anuais de temperatura (0C). A repartição das espécies arbóreas mostrou alta heterogeneidade ao longo dos Estados que compõem a Costa Atlântica Brasileira, onde, do total de 1837 espécies, 1078 ocorrem em apenas um Estado; 440 em apenas dois; 173 em apenas três Estados; 88 em apenas quatro; 33 em apenas cinco Estados; 17 em apenas seis Estados e 8 espécies estão presentes em sete Estados, sendo que, nenhuma das espécies é comum a todos os Estados. Os resultados obtidos indicam características de alta heterogeneidade e complexidade da composição florística das Matas Úmidas, ressaltando-se que, localmente, a diversidade da flora é muito expressiva e ainda existe uma grande lacuna nas informações a respeito dos fatores condicionantes destas características. / The present work studies the distribution of arboraceous species which occur over the Wet Forest of Brazilian Atlantic East-Coast, from evaluating the interference of environmental factors. The arboraceous species data were obtained from floristic and fitosociological surveys using cartographical basis of RADAMBRASIL Project. For obtaining climatic data, it was used RADAMBRASIL and CEPETC/INMET Projects. By using geographical information system (GIS - SPRING 3.6 and IDRISI 32 software), it was mapped and analyzed arboraceous species, climatic, geomorphologic and vegetation factors distribution. Simple linear and multiple regression analyze were carried out aiming to test the correlation index of overlaid map data (index V CRAMERþS), from thematic maps overlapped on GIS. Corresponding factorial analyze also were carried through. The statistical analyses of species geographical distribution overlaid with environmental variables map data, presented high correlation, detaching the data referring to insolation (hs) and annual temperature averages (mm). Arboraceous species distribution showed high heterogeneity along the Brazilian States, which compose Brazilian Atlantic East-Coast, where, from a total 1837 species, 1078 occur at only one State; 440 at two States; 173 at three States; 88 species at only four States; 33 at five States; 17 at only six States and 8 species are found at 7 States, being that, none species are common to all States. The obtained results indicated characteristics of high heterogeneity and complexity of the Wet Forest floristic composition, standing out itself that flora diversity, locally, is very expressive and there is a large gap over the information despite to the conditioning factors of these characteristics

Vitamin C (ascorbate and dehydroascorbic acid) is vital for plants and found throughout the plant cell including in the apoplast. The structure of ascorbate was determined eighty years ago; however, many of its degradation pathways remain unclear. Numerous degradation products of ascorbate have been reported to occur in the apoplast but many still remained unidentified. Ascorbate is well known as an antioxidant, and acts to quench reactive oxygen species (ROS), such as hydrogen peroxide and ozone in the plant apoplast. The immediate oxidation product of ascorbate is dehydroascorbic acid (DHA), which may be quickly hydrolysed to diketogulonic acid (DKG). The further reactions of radiolabelled and non-radiolabelled DHA and DKG with various ROS have been investigated. Differences were observed in the products formed from the various ROS, allowing a unique fingerprint of oxidation products to be described for each ROS. Equally, different compounds were produced depending on the starting substrate; for example cyclic oxalyl threonate was only observed in the reactions of DHA and not DKG. A major oxidation product of DHA is OxT. A novel enzyme activity involving the transfer of the oxalyl group from OxT to an acceptor substrate such as a sugar has been detected. This enzyme activity could have potential cell wall modification roles, in the formation of oxalate cross-linkages between cell wall components. This would provide a novel role for ascorbate derivatives in cell growth. Vitamin C is also a vital component of the human diet, and most dietary ascorbate comes from plants such as salads. The degradation of ascorbate during post-harvest processing and storage of salad leaves has been investigated. Spinach leaves were found to be particularly prone to losing ascorbate during the industrial washing process. The use of radiolabelled ascorbate has allowed the determination that the major degradation product formed from ascorbate during spinach washing was oxalate.

Macroecology is the study of relationships between organisms and the environment at large spatial and temporal scales. This field of research examines patterns in species abundance, distribution and diversity. Understanding patterns in species distribution and richness can contribute significantly to our knowledge of community assembly and macroecological patterns, as well as to the effective conservation of threatened species and habitats. Although there have been a plethora of studies on birds in India over the years, there is a critical need to accurately delineate species distributions and understand patterns of richness. The focus of this study was to understand the factors (abiotic and biotic) that influence the distribution and composition of bird species in the Western Ghats, as well as to explore patterns in their geographic range sizes. The objectives of this study were addressed at the scale of the entire Western Ghats using a combination of field surveys, secondary data collection and species distribution modeling. The specific approaches to address these questions and the findings are outlined below. Chapter 2: Bird species in the Western Ghats – Patterns in composition and richness Fine-scale data on species presence and abundance are essential for exploring patterns in species distribution and richness. Despite the fact that birds have been extensively studied in the Western Ghats, systematic data collection and compilation of information over the entire mountain range has not been carried out, especially for the purpose of testing macroecological questions. This chapter describes patterns in bird species presence, abundance, composition and richness within the Western Ghats. The study area, site selection protocol and the sampling technique have also been described in detail. This dataset establishes a baseline of information about birds in the Western Ghats and subsets of this larger dataset will be used to address various questions in the following chapters. Chapter 3: Predicting bird species distribution in the Western Ghats Detailed knowledge of species’ ecological and geographical distributions is fundamental for conservation, as well as for understanding ecological and evolutionary determinants of spatial patterns of biodiversity. However, occurrence data for a vast majority of species are sparse, resulting in information about species distributions that is inadequate for many purposes. Species distribution models attempt to provide detailed predictions of distributions by relating presence or abundance of species to environmental predictors. In this chapter, we describe the usage of Maxent, a species distribution modelling technique based on presence-only data, to predict the distributions of bird species within the Western Ghats. For this purpose, we put together primary locations of bird species presence along with a published dataset. Using a number of important environmental layers, predicted species distribution maps were derived for 98 bird species, including 13 endemics, in the Western Ghats. Additionally, we calculated predicted range sizes for each of these species and obtained percentage contributions of important environmental predictors to each species’ distribution. This is the first study to develop species distribution models for bird species within the Western Ghats. Chapter 4: Patterns of range size among bird species Understanding large-scale patterns of variation in species geographic range size is fundamental to questions in macroecology and conservation biology. In general, range is believed to be influenced by a combination of environmental factors, evolutionary history and biotic interactions, mediated by species specific traits. These patterns need to be examined even for well-studied taxa like birds, especially within biodiversity hotspots faced by persistent degradation due to anthropogenic activities such as the Western Ghats. In this chapter, we use a dataset of 98 bird species within the Western Ghats to examine trends in range sizes, measured as latitudinal extent of occurrence and predicted range size from species distribution models. We show a significant relationship between latitude and range size for these bird species, supporting Rapoport’s rule. As far as we know, this relationship has never been tested at such low latitudes for birds. We also find that species traits such as body size, mean abundance and diet do not seem to show any discernable effect on patterns of range size. Additionally, we found that widely-used bird species range maps (in this case, from BirdLife International) are inaccurate representations of species ranges in comparison to the predicted species distribution maps that were derived in the previous chapter. We quantitatively demonstrated that these expert-drawn maps need to re-evaluated, especially since they are used to make conservation decisions. This is the first study to quantify species range sizes of birds within the Western Ghats and assess such range maps that are used to determine conservation status of species. Chapter 5: Environmental predictors of bird species distribution One of the major goals in ecology is to understand patterns and processes that determine species diversity. The drivers of global species richness gradients have been studied, especially in the case of birds, in terms of contemporary and historical factors. Such broad scale processes may not always reflect the processes affecting richness and distribution at smaller scales. Therefore, understanding the factors that influence individual species distributions is the first step towards this larger goal. In this chapter, we examined the environmental predictors that contributed to the predicted distribution of bird species observed in the Western Ghats, using the variable importance contribution values derived in Chapter 3. We found that a large proportion of the 98 bird species studied were influenced by normalized differential vegetation index, annual precipitation and elevation. The predictors did not differ among birds of different diet guilds and body size classes. Using Prinicipal components analysis, we observed that all 98 bird species are spread out across the environmental ordination space depicted by the PC axes 1 and 2. These axes are governed by measures of habitat heterogeneity and water-energy related variables, consistent with other tropical studies. The insectivorous guild seemed to occupy a variety of environmental niches across this space and other guilds seemed to be nested within the insectivorous guild. Similarly, larger sized birds were spread across the entire environmental ordination space, with species of smaller sizes nested within. This is the first step in trying to understand environmental predictors acting on birds in the Western Ghats. Further detailed studies need to be carried out to come to definite conclusions. Chapter 6: Relative roles of floristics and vegetation structure on bird species composition On the basis of the hierarchical model of habitat selection, it is known that birds select suitable habitats based on vegetation structure (physiognomy) at coarse biogeographic scales, and plant species composition (floristics) at more local scales. This chapter examines the relative influence of tree species composition and vegetation structure on bird species composition in the Western Ghats. These relationships were specifically assessed across the entire Western Ghats, within regions of the Western Ghats as well as within specific forest types. We found that floristics had a strong association with bird species composition across the Western Ghats and within evergreen and mixed deciduous habitat types. This association seems to be independent of the structural variation in the region. There was a decrease in association strength from the southern to the northern Western Ghats, in terms of both floristics and structure. We did not find an association between vegetation structure and insectivore composition, whereas phytophage composition did show a stronger association with floristics than structure. This is the first study at the scale of the entire Western Ghats to test the relative roles of floristics and vegetation structure. Taken as a whole, this dissertation examines large-scale macroecological questions regarding species distribution, range size and patterns of composition using primary data at the scale of the Western Ghats. The findings of this study have established a foundation that will help further our understanding of species distribution and richness in the Western Ghats, and aid in the decision making for conservation strategies in the future.

Invasões biológicas estão entre as principais causas da perda de biodiversidade no planeta. Ambientes isolados como as ilhas oceânicas e ambientes sujeitos a distúrbio antrópico são considerados mais propensos à invasão. Para as plantas, o sucesso na invasão pode ter relação com a superioridade na competição com as espécies nativas, que pode ocorrer através da produção de substâncias alelopáticas. Dentre as 100 principais espécies invasoras do planeta está a Leguminosa Leucaena leucocephala, que produz substâncias com potencial alelopático e está estabelecida em ilhas oceânicas tropicais em todo o mundo. No Brasil, a invasora foi introduzida na ilha de Fernando de Noronha, onde ocupa vastas áreas. Apesar da relevância desta ilha para a conservação da biodiversidade, não há informações essenciais para o manejo da invasora, como a situação da invasão e seus fatores determinantes. Neste trabalho, realizado em Fernando de Noronha, utilizamos experimentos para investigar a alelopatia como mecanismo associado à invasão e para avaliar o efeito de L. leucocephala sobre o estabelecimento de Erythrina velutina (Leguminosae), espécie nativa comum na ilha, mas frequentemente excluída das áreas invadidas por L. leucocephala. Não encontramos indícios de efeitos alelopáticos de L. leucocephala sobre a germinação de E. velutina, mas a exótica reduziu o crescimento e a sobrevivência da nativa. O efeito negativo é potencializado quando L. leucocephala está associada à Capparis flexuosa (Capparaceae), única espécie nativa frequentemente encontrada em áreas invadidas. Isoladamente, o efeito de C. flexuosa sobre E. velutina varia de positivo a neutro, evidenciando que o saldo das interações entre espécies nativas é alterado na presença de uma exótica. Adicionalmente, diagnosticamos a extensão atual da invasão e sua expansão nos últimos 20 anos, seus fatores determinantes e o impacto sobre a comunidade de plantas nativas em Fernando de Noronha. O diagnóstico da invasão mostrou que L. leucocephala está amplamente distribuída pela ilha, povoando densamente a maioria dos locais onde ocorre. A área ocupada pela espécie aumentou cerca de 40% nos últimos 20 anos, e não há restrições ambientais para o estabelecimento da exótica, embora ela seja favorecida pela atividade agropecuária. Em áreas invadidas o número de espécies nativas diminui quase pela metade e observamos uma tendência à homogeneização da comunidade. É provável que o alto grau de perturbação antrópica em Fernando de Noronha gere limitações à dispersão e modifique os ambientes tornando-os desfavoráveis para o estabelecimento de espécies nativas. Entretanto, há fortes evidências de que L. leucocephala causa mudanças ecológicas na ilha influenciando na perda espécies nativas. Considerando a importância biológica de Fernando de Noronha, ações de controle da expansão da exótica e restauração das áreas invadidas demonstram-se urgentes / Biological invasions are among the main causes of biodiversity loss on the planet. Isolated environments such as oceanic islands and disturbed environments are considered more prone to invasion. For plants, the invasion success may be related to advantages in competition with native species, which may occur through the production of allelopathic substances. Among the 100 most invasive species on the planet is the legume Leucaena leucocephala, which produces substances with putative allelopathic effects and is established on tropical oceanic islands worldwide. In Brazil, the invader was introduced on the island of Fernando de Noronha, where it occupies vast areas. Despite the relevance of this island for biodiversity conservation, important information for the management of the invasion, as its extension and determinants, do not exist. In this work we use experiments to investigate allelopathy as a mechanism associated with the invasion and to evaluate the effect of L. leucocephala on the establishment of Erythrina velutina, a native species common on the island, but often absent from invaded areas. We found no evidence of allelopathic effects of L. leucocephala in the germination of E. velutina, but the exotic reduced the growth and survival of the native. The negative effect is enhanced when L. leucocephala is associated with Capparis flexuosa, the only native species often found in heavily invaded areas. When alone, the effect of C. flexuosa on E. velutina varies from positive to neutral, indicating that the balance of interactions between native species is altered in the presence of an exotic. Additionally, we describe the current distribution of L. leucocephala and its expansion in the last 20 years in Fernando de Noronha. We also investigate the environmental and anthropic factors determining the invasion and the impact of L. leucocephala on the plant community. We found that L. leucocephala is widely distributed throughout the island, densely populating most places where it occurs. The area occupied by the species increased about 40% in the last 20 years, and there are no environmental restrictions for the establishment of exotic, although it is favored by farming. In invaded areas, the number of dominant native species decreased by almost half and we observed a tendency towards homogenization of the community. It is likely that the high degree of human disturbance in Fernando de Noronha poses dispersal limitations and modifies the environments making them unsuitable to the establishment of natives. However, there are strong evidences that L. leucocephala is driving ecological changes on the island that influence in native species loss. Considering the biological importance of Fernando de Noronha, actions to control the expansion of exotic and to restore the invaded areas are urgent

Made available in DSpace on 2014-06-11T19:27:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-11Bitstream added on 2014-06-13T20:16:47Z : No. of bitstreams: 1 oliveira_am_me_botib.pdf: 3138768 bytes, checksum: 29295f39631d00207dcd4a354dfb5eeb (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Caracterização, diversidade, estrutura e estágio sucessional da comunidade de árvores de uma Floresta Estacional Decidual no Sudeste do Brasil. A composição florística, a estrutura, a diversidade e o estágio sucessional de um fragmento de floresta foram analisados nesse estudo. O trabalho foi desenvolvido no município de Votuporanga, onde o clima é considerado Aw. Foi utilizado o método de parcelas (1 ha), amostrando todos os indivíduos arbóreos com DAS 5 cm. Foram calculados os valores de freqüência, densidade e dominância (absolutos e relativos), índice de valor de importância (IVI) e os índices de Shannon-Wiener (H’) e Equabilidade (J’). A estrutura horizontal, o estágio sucessional e a formação vegetacional foram analisados. Foram amostrados 1635 indivíduos e as famílias mais ricas foram Fabaceae (17), Myrtaceae (oito), Rubiaceae (oito) e Bignoniaceae (cinco). Casearia gossypiosperma Briq. foi a espécie com o maior IVI. O índice de diversidade de Shannon-Wienner (H´) foi 2,87 nats.indivíduo-1 e a equabilidade (J) foi 0,66 . Observou-se que 93% dos indivíduos arbóreos apresentaram diâmetros entre 1 e 20 cm. Árvores pioneiras compõem 55% dos indivíduos amostrados. A predominância de indivíduos com fenologia foliar decídua (79%) determinou a classificação do fragmento como Floresta Estacional Decidual. Assim, com este trabalho foi possível identificar uma área de Floresta Estacional Decidual no noroeste do estado e oferecer conhecimento, que são essenciais, sobre a flora, a estrutura florestal e o comportamento ecológico de Florestas Estacionais Deciduais no Estado de São Paulo / Characterization, diversity, structure and successional stage of the tree community of a Seasonal Deciduous Forest in southeastern Brazil. Floristic composition, structure, diversity, and successional stage of a fragment forest have been analyzed in this study. The work was carried out Votuporanga, where the climate is considered Aw. Plot method was used (1 ha), sampling all trees 5 cm from HSD. We calculated the values of frequency, density and dominance (absolute and relative), index of importance value (IVI), the Shannon-Wiener diversity (H') and the equability (J'). The horizontal structure, the successional stage and the vegetation formation were analyzed. We sampled 1635 individuals and the richest families were Fabaceae (17), Myrtaceae (eight), Rubiaceae (eight) and Bignoniaceae (five). Casearia gossypiosperma Briq. was the species with the highest IVI. The Shannon-Wiener diversity (H') was 2.87 nats.individual-1 and the equability (J) was 0.66. It was observed that 93% of the trees individuals had diameters between 1 and 20 cm. Pioneers trees represent 55% of samples. The prevalence of individuals with deciduous leaf phenology (79%) determined the classification of the fragment as a Deciduous Seasonal Forest.Thus, this work enabled the identification an area of deciduous seasonal forest in the northwest of the state and offered essential knowledge about the flora, the forest structure and the ecology of deciduous forests in the State of São Paulo