O lobo-guará é uma espécie de ampla distribuição na América do Sul, tendo no Brasil sua maior área de ocorrência. No entanto, as modificações das áreas naturais principalmente destinadas à agropecuária tornam a espécie vulnerável à extinção. A investigação objetivou conhecer em larga escala a área de distribuição potencial gerada por atributos ambientais favoráveis e áreas adequadas à sua ocorrência nos biomas brasileiros e investigar como a espécie responde à estrutura da paisagem, avaliando os efeitos de ambientes modificados pelo homem na sua ecologia espacial, nos padrões de atividade e na movimentação. Modelos de distribuição de espécie foram gerados pelo Maxent, utilizando uma base de pontos de localização de presença a partir de 2000 para o Cerrado (Ce), Pantanal (Pa), Mata Atlântica (MA) e Pampas (Pp) e um conjunto de onze variáveis ambientais não correlacionadas (topográficas, climáticas e paisagísticas). Para análises de ecologia espacial, das atividades e de movimentação, utilizou-se localizações de telemetria (GPS) de animais habitantes de áreas protegidas (AP), e indivíduos em paisagens modificados (AM). Análises de áreas de vida (AV) foram realizadas utilizando o estimador AKDE e associadas com classificação da paisagem local. Os modelos de distribuição do lobo-guará apresentaram uma área de distribuição potencial de 78% do total dos biomas. Apesar de possuírem grandes proporções de áreas adequadas (Ce, 90%; Pa, 93%; MA, 65% e Pp, 6%), somente um pequeno percentual (4,4% do Ce e 4,7% da MA) possui adequabilidade ambiental acima de 50%. Dos atributos que favorecem sua presença, a altitude (para todos os biomas), a precipitação (Ce e Pa), diferenças de temperatura e uso e cobertura do solo (Ma e Pp) foram os mais importantes. Em nível local, animais apresentaram média de AV de 90Km2 em AP e 41Km2 em AM, uma diferença significativa (p<0,01) com áreas diretamente proporcionais ao percentual de áreas naturais na paisagem. Ainda, apesar dos padrões regulares de atividade não mostrarem grandes mudanças, o período de repouso foi significativamente maior (p<0,01) entre os animais AM (46% do dia) que em animais AP (25% do dia). Lobos-guarás de AP e AM não apresentaram grandes diferenças no deslocamento diário com média geral de 14km caminhados por dia, com comprimentos de passos de 1Km. Diferenças no comprimento de passo foram relacionadas à composição da diversidade de contato de classes da paisagem com a proporção de ambientes naturais no passo (quanto maior as variáveis, maior o passo). Passos menores refletem menor persistência de movimento interferindo no deslocamento diário. Com os resultados desse estudo identificou-se a MA e Pa muito importantes, mas o Ce como bioma mais adequado à espécie. Foram encontrados indícios de que a estrutura de suas AV, o uso da paisagem, as atividades e movimentação são afetados pela paisagem modificada. Isso pode comprometer a viabilidade populacional, interferindo na presença em uma área e refletindo no seu potencial de distribuição. As estratégias de manejo de uso do solo, e a recuperação e conexão de áreas adequadas são urgentes e necessárias para que o lobo-guará permaneça presente e funcional nas paisagens dos biomas brasileiros. / The maned wolf has an extensive distribution range throughout South America with Brazil holding the largest portion of this area. However, the species is presently under a vulnerable status due to natural habitats alteration especially from farming and ranching. This study aimed to observe in large scale the potential distribution area indicated by favorable environmental attributes and suitable habitats to its presence within the Brazilian biomes and further to investigate how the species respond to the landscape structure, evaluating the effects of human-modified landscapes on its spatial ecology, activity patterns and movements. Species distribution models were generated using Maxent with a database of presence-only locations from 2000 though 2015, of the Cerrado (Ce), Pantanal (Pa), the Atlantic Forest (AF), and the Pampas (Pp) biomes, and eleven uncorrelated environmental variables (topographic, climatic, and landscape-based). As for the spatial ecology, activity and movement analysis, GPS-based telemetry locations were used from animals inhabiting protected (PAs) and disturbed areas (DAs). Home range (HR) analysis was performed using the AKDE estimator and then associated with the landscape-classified image. The distribution models for the maned wolf showed a potential distribution area of 78% of the total biomes range. Despite the high proportion of suitable areas (Ce, 90%; Pa, 93%; AF, 65%, and Pp, 6%), only a small percentage of the biomes (4.4% for Ce and 4.7% for AF) presented values over 50% suitable. Concerning the attributes that favor its presence, the altitude (for all the biomes), the precipitation (Ce and Pa), the temperature differences and land use (AF and Pp) were the most important. At the local scale, maned wolves showed HR sizes (average) with significant differences (p<0.01) between the 90Km2 (PA) and 41Km2 (DA) with HR size directly related to the proportion of natural areas. Although the general activity patterns were not considerably different between PA and DA, the resting periods of DA\'s animals (46% of the day) were significantly different (p<0.01) than the period of PA\'s wolves (46% of the day). Animals did not show changes on the daily movement patterns, accounting with 14km in general average and 1km of average step length (no major differences as well). The variation on the step length was related to the association of the diversity of contacts between landscape classes with the proportion of natural classes at each step (as bigger the variable values, bigger the step). As a consequence of smaller steps, constancy of movement decreases. Considering the results, the AF and Pa outstand as very important biomes, however the Ce was indicated as the most suitable biome. Furthermore, the research indicated signs that the HR structure and the landscape use, besides the activity patterns and the movement are affected by altered landscapes. This might compromise the population viability, interfering directly on its presence in an area and affecting the species distribution. Thus, a proper land use management aiming the recovering of degraded habitats is an important strategy tor the maned wolf conservation, so the species can long last survive across the Brazilian biomes.

Le changement climatique et les invasions biologiques sont parmi les plus grandes menaces de la biodiversité et leurs impacts pourraient augmenter jusqu’à la fin du siècle. Parmi les espèces envahissantes, les fourmis sont un groupe particulièrement néfaste dû à leurs impacts sur les espèces natives, les processus écosystémique, la santé, l’agriculture et l’économie. L’objectif de cette thèse était de prédire les invasions de fourmis – en particulier avec le changement climatique qui pourrait favoriser les invasions en éliminant des barrières thermiques. J’ai utilisé trois approches complémentaires afin d’étudier le potentiel de différentes espèces à envahir : des modèles de distribution, des expériences comportementales et l’analyses d’une base de données de traits écologiques. J’ai modélisé l’aire favorable pour 15 espèces de fourmis parmi les pires, à la fois globalement, par continents, et dans les 34 hotspots de biodiversité. La distribution potentielle de seulement cinq espèce est prédite de diminuer (jusqu’à 35.8%) avec le changement climatique et l’aire potentielle diminue pour la plupart des espèces jusqu’à 63.2%. Les hotspots d’invasions de fourmis se situaient surtout dans des régions tropicales et subtropicales et ils correspondent particulièrement aux hotspots de biodiversité. Contrairement à ce qui est généralement admis, le changement climatique et les invasions biologiques n’agiront pas de manière synergique pour les fourmis. Par contre, les invasions de fourmis resteront probablement un problème global majeur, en particuliers dans les zones où les hotspots de biodiversité et les hotspots d’invasion se superposent. Les modèles de distribution ont identifié de larges zones de recouvrement entre aires favorables de plusieurs espèces de fourmis envahissantes. Dans le futur, ces espèces pourraient arriver simultanément dans les mêmes régions et entrer en compétition. Dans une série d’expériences, j’ai testé les différences comportementales entre 7 espèces de fourmis envahissantes (Anoplolepis gracilipes, Paratrechina longicornis, Myrmica rubra, Linepithema humile, Lasius neglectus, Wasmannia auropunctata et Pheidole megacephala). J’ai découvert deux stratégies comportementales différentes. Les interactions au niveau de la colonie ont suivi des processus démographiques plus complexes. De plus, j’ai mis au point deux expériences pour tester la capacité des fourmis envahissantes à explorer un nouvel espace et à exploiter des ressources. J’ai trouvé des différences significatives entre espèces et leur capacité à dominer par interférence comportementale était négativement corrélée à leurs capacités à découvrir et exploiter des ressources. Cette série d’expériences suggère que les ‘mécanismes’ d’invasion sont plus complexes que ce qui est généralement suggéré et que différentes espèces pourraient utiliser des stratégies comportementales différentes. Étant donné qu’il existe plus de 250 espèces de fourmis exotiques, il serait intéressant de pouvoir identifier à l’avance des futurs envahisseurs potentiels. Afin d’identifier des traits associés au caractère envahissant des fourmis, j’ai mis en place une base de données qui contient 2193 espèces de fourmis et 24 traits écologiques. J’ai effectué une analyse préliminaire de différences de traits entre fourmis natives et envahissantes qui a montré qu’il existe clairement des groupement distincts de natives et envahissantes, avec les espèces exotiques au milieu. Ces résultats pourraient servir de base pour construire un modèle prédictif des invasions de fourmis. Ces différentes approches (modèles, expériences, base de données) sont complémentaires car elles s’intéressent à des aspects différents du futur des invasions de fourmis qui sera vraisemblablement fortement influencé par le changement climatique. Le pires envahisseurs de demain ne seront probablement pas les même qu’aujourd’hui et les zones les plus à risque pourraient changer également. / Climate change and biological invasions are both among the greatest threats to biodiversity and their impacts might increase by the end of the century. Among invasive species, ants are a prominent group due to their negative impacts on native species, ecosystem processes, human and animal health, agro-ecosystems and the economy. The objective of this thesis was to forecast future ant invasions – especially in the light of on-going climate change, which is generally thought to favour invasive species by removing thermal barriers. I used three complementary approaches to study the potential of different ant species to invade in the future: species distribution modelling, behavioural experiments and the analysis of a database of ecological traits. I modelled suitable area for 15 of the worst invasive ant species, both currently and with predicted climate change, globally, regionally and within the world’s 34 biodiversity hotspots. Surprisingly, the potential distribution of only five species was predicted to increase (up to 35.8%) with climate change, with most declining by up to 63.3%. The ant invasion hotspots are predominantly in tropical and subtropical regions of South America, Africa, Asia and Oceanic islands, and particularly correspond with biodiversity hotspots. Contrary to general expectations, climate change and biological invasions will not systematically act synergistically for ants. In addition, I found that the impacts of climate change can change over time and even reverse the trend of the impact (i.e., an increase instead of a decrease or vice versa). However, ant invasions will likely remain as a major global problem, especially where invasion hotspots coincide with biodiversity hotspots. The species distribution models have identified large potentially overlapping distributions of several invasive ants. In the future, these species may arrive simultaneously in the same regions and compete with each other. In a series of experiments, I tested behavioural differences among 7 highly invasive ant species (Anoplolepis gracilipes, Paratrechina longicornis, Myrmica rubra, Linepithema humile, Lasius neglectus, Wasmannia auropunctata and Pheidole megacephala). I discovered two different behavioural strategies among invasive ants. Interactions at the colony level, exhibited more complex demographic processes and more variability. Further, I investigated resource competition and differences in resource exploitation. I found significant differences among species, with competitive abilities that were negatively correlated with behavioural dominance. This series of experiments suggests that the ‘mechanisms’ of invasiveness are more complex than previously thought and that different invasive ant species may use different behavioural strategies. Since there are more than 250 exotic species of ants, it would be interesting to identify potential future invaders. In order to identify traits associated with invasiveness in ants, I set up a database with 2193 ant species and 24 ecological characteristics. I performed a preliminary analysis of trait differences between native and invasive ants that shows clearly different clusters of invasive and native species, with exotic species in between. These results could be used as a basis to construct a predictive model of future ant invasions. The different methods used (models, experiments, database) are complementary in that they explore different aspects of the future ant invasions which are likely to be influenced by on-going climate change. The worst invaders of tomorrow may not be the same as today and similarly, areas most at risk are likely to change.

For the west coast of North America, from northern California to southern Washington, a habitat suitability prediction framework was developed to support wave energy device siting. Concern that wave energy devices may impact the seafloor and benthos has renewed research interest in the distribution of marine benthic invertebrates and factors influencing their distribution. A Bayesian belief network approach was employed for learning species-habitat associations for Rhabdus rectius, a tusk-shaped marine infaunal Mollusk. Environmental variables describing surficial geology and water depth were found to be most influential to the distribution of R. rectius. Water property variables, such as temperature and salinity, were less influential as distribution predictors. Species-habitat associations were used to predict habitat suitability probabilities for R. rectius, which were then mapped over an area of interest along the south-central Oregon coast. Habitat suitability prediction models tested well against data withheld for crossvalidation supporting our conclusion that Bayesian learning extracts useful information available in very small, incomplete data sets and identifies which variables drive habitat suitability for R. rectius. Additionally, Bayesian belief networks are easily updated with new information, quantitative or qualitative, which provides a flexible mechanism for multiple scenario analyses. The prediction framework presented here is a practical tool informing marine spatial planning assessment through visualization of habitat suitability. / Graduation date: 2012

No description available.

Invasive alien plants have widespread ecological and socioeconomic impacts throughout many parts of the world, including Swaziland where the government declared them a national disaster. Control of these species requires knowledge on the invasion ecology of each species including how they interact with the invaded environment. Species distribution models are vital for providing solutions to such problems including the prediction of their niche and distribution. Various modelling approaches are used for species distribution modelling albeit with limitations resulting from statistical assumptions, implementation and interpretation of outputs. This study explores the usefulness of Bayesian networks (BNs) due their ability to model stochastic, nonlinear inter-causal relationships and uncertainty. Data-driven BNs were used to explore patterns and processes influencing the spatial distribution of 16 priority invasive alien plants in Swaziland. Various BN structure learning algorithms were applied within the Weka software to build models from a set of 170 variables incorporating climatic, anthropogenic, topo-edaphic and landscape factors. While all the BN models produced accurate predictions of alien plant invasion, the globally scored networks, particularly the hill climbing algorithms, performed relatively well. However, when considering the probabilistic outputs, the constraint-based Inferred Causation algorithm which attempts to generate a causal BN structure, performed relatively better. The learned BNs reveal that the main pathways of alien plants into new areas are ruderal areas such as road verges and riverbanks whilst humans and human activity are key driving factors and the main dispersal mechanism. However, the distribution of most of the species is constrained by climate particularly tolerance to very low temperatures and precipitation seasonality. Biotic interactions and/or associations among the species are also prevalent. The findings suggest that most of the species will proliferate by extending their range resulting in the whole country being at risk of further invasion. The ability of BNs to express uncertain, rather complex conditional and probabilistic dependencies and to combine multisource data makes them an attractive technique for species distribution modeling, especially as joint invasive species distribution models (JiSDM). Suggestions for further research are provided including the need for rigorous invasive species monitoring, data stewardship and testing more BN learning algorithms. / Environmental Sciences / D. Phil. (Environmental Science)

Made available in DSpace on 2014-07-29T16:21:19Z (GMT). No. of bitstreams: 1 Faleiro Frederico Dissertacao.pdf: 1687158 bytes, checksum: e1a8a44e89beea38d1a839934c890e56 (MD5) Previous issue date: 2012-03-28 / The human actions has triggered many threats to biodiversity like land-use and climate changes, overexploitation, pollution, and introduction of invasive species, which can affect organisms both at local and global scale. The science of spatial conservation prioritization emerged as a quantitative approach to support the spatial decisions in face of these threats, while minimizing the socioeconomic and political conflicts. Here we developed spatial solutions to the conservation of non-flying mammals from Brazilian Cerrado considering the socioeconomic costs and the opportunities of environmental governance (first objective). Further, we generated solutions to face the land-use and climate change taking into account the dispersal abilities of species and uncertainties in the species distribution modeling (SDM) process (second objective). We considered the current network of reserves of the Cerrado in both objectives. We built SDMs for 154 species combining model projections weighted by their statistical fit to produce consensus maps of species distribution grouped in three distinct types of models (envelope, statistical and machine-learning models), for both current future scenarios of climate (used only in the last aim). For the first goal, we used the current predicted distribution to run spatial prioritization analyses indicating the best sites for the conservation investment considering human population density, land cost, anthropogenic land use, level of environmental governance, and the distribution of species in trade-off analyses. For the second goal, we used both current and future predicted distribution to run optimization procedures and propose priority sites for conservation, while minimizing species climate-forced dispersal distance , the mean uncertainty associated to the SDM process, and taking into account the future changes in the landscape (by our land use model). SDMs indicated that species-rich sites converge to regions with high population density, high land cost, high anthropogenic land use, and with diverse levels of environmental governance. There was a significant change in spatial priorities when socioeconomic and political dimensions were included in analyses: top priority sites moved towards the north. This spatial change reduced by 68% the potential conservation conflicts with human population, by 72% the likely conflicts arising from land cost and by 68% anthropogenic land use. It also increased by 51% the beneficial effect of environmental governance. Including land-use changes and the modeling uncertainty in the conservation planning process changed significantly the spatial distribution of priority sites in the region. While the inclusion of land-use models altered the spatial location of priority sites at the regional scale, the effects of climate change tended to take place at the local scale. Note that, our solutions already include possible dispersal corridors linking current and future priority sites for mammal conservation, as well as a formal risk analysis based on planning uncertainties. Our results allowed dealing with both complex nature of conflicts among socioeconomic and political dimensions, and the dynamic problem imposed mainly by land-use and climate change. Thus, our analyses figure as a methodological prospect supporting the decision-make process and the consequent translation of conservation planning outcomes into conservations actions / As ações humanas têm desencadeado diversas ameaças a biodiversidade como as mudanças de uso do solo e do clima, sobre-exploração, poluição e introdução de espécies invasoras, que afetas os organismos da escala local até a global. A ciência da conservação espacial para conservação emergiu como uma abordagem quantitativa que tem o objetivo de auxiliar escolhas espaciais que lidem com essas ameaças enquanto minimizam conflitos socioeconômicos e políticos. Aqui nós desenvolvemos soluções espaciais para conservação de mamíferos não voadores do Cerrado considerando os custos socioeconômicos e as oportunidades vindas da governança ambiental (primeiro objetivo). Além disso, nós geramos soluções espaciais que lidem com as mudanças do uso do solo e climáticas levando em consideração as capacidades de dispersão das espécies e as incertezas associadas ao processo de modelagem de distribuição de espécies (MDE) (segundo objetivo). Em ambos objetivos nós consideramos a atual rede de reservas do Cerrado. Nós modelamos a distribuição de 154 espécies combinando as projeções dos modelos e pesado pelo ajuste estatístico para produzir os mapas consenso de distribuição das espécies, agrupados em três distintos tipos de modelos (modelos de envelope, estatísticos e de inteligência artificial), para a atualidade e projetados para o futuro (usado apenas no último objetivo). Para o primeiro objetivo, nós usamos as predições da atual distribuição das espécies para realizar as análises de priorização espacial, indicando os melhores locais para investimento considerando a densidade humana, custo da terra, uso do solo antropogênico, nível de governança ambiental e a distribuição das espécies na perspectiva da análise de demandas conflitantes. Para o segundo objetivo, nós usamos a distribuição atual e futura das espécies para realizar o procedimento de otimização e propor locais para conservação que minimizem os efeitos da dispersão induzida pelas mudanças climáticas, incertezas associadas ao processo MDE e considerando as futuras mudanças na paisagem (através do nosso modelo de uso do solo). A MDE indicou que locais ricos em espécies convergem para locais com alta densidade populacional, alto custo de terra, alta proporção de uso do solo voltado para atividades humanas e diversos níveis de governança ambiental. Houve significativas mudanças nas prioridades espaciais quando as dimensões socioeconômicas e políticas foram incluídas nas análises, fazendo que os locais prioritários mudassem para o norte. Essa mudança espacial reduziu em 68% de potenciais conflitos com população humana, em 72% de conflitos de custo da terra, em 68% de conflitos com o uso do solo antropogênico e 51% de aumento dos possíveis benefícios da governança ambiental. Quando incluímos as mudanças de uso de solo e a incerteza da modelagem no processo de planejamento, os locais prioritários mudaram significativamente na região. Enquanto a inclusão das mudanças no uso do solo alterou a localização espacial dos locais prioritários em escala regional, os efeitos da mudança climática tenderam a ocorrem em escala local. Note que nossas soluções já incluíram possíveis corredores de dispersão para ligação entre as atuais áreas prioritárias com aquelas importantes no futuro, tão bem quanto a análise de risco baseado nas incertezas do planejamento. Nossos resultados permitiram lidar tanto com a complexa natureza dos conflitos entre dimensões socioeconômicas e políticas quanto com problema dinâmico imposto principalmente pelas mudanças do uso do solo e climáticas. Assim, nossas análises auxiliam metodologicamente a dar suporte no processo de tomada de decisão e a consequente tradução dos resultados de planejamentos de conservação em ações de conservação

O lobo-guará é uma espécie de ampla distribuição na América do Sul, tendo no Brasil sua maior área de ocorrência. No entanto, as modificações das áreas naturais principalmente destinadas à agropecuária tornam a espécie vulnerável à extinção. A investigação objetivou conhecer em larga escala a área de distribuição potencial gerada por atributos ambientais favoráveis e áreas adequadas à sua ocorrência nos biomas brasileiros e investigar como a espécie responde à estrutura da paisagem, avaliando os efeitos de ambientes modificados pelo homem na sua ecologia espacial, nos padrões de atividade e na movimentação. Modelos de distribuição de espécie foram gerados pelo Maxent, utilizando uma base de pontos de localização de presença a partir de 2000 para o Cerrado (Ce), Pantanal (Pa), Mata Atlântica (MA) e Pampas (Pp) e um conjunto de onze variáveis ambientais não correlacionadas (topográficas, climáticas e paisagísticas). Para análises de ecologia espacial, das atividades e de movimentação, utilizou-se localizações de telemetria (GPS) de animais habitantes de áreas protegidas (AP), e indivíduos em paisagens modificados (AM). Análises de áreas de vida (AV) foram realizadas utilizando o estimador AKDE e associadas com classificação da paisagem local. Os modelos de distribuição do lobo-guará apresentaram uma área de distribuição potencial de 78% do total dos biomas. Apesar de possuírem grandes proporções de áreas adequadas (Ce, 90%; Pa, 93%; MA, 65% e Pp, 6%), somente um pequeno percentual (4,4% do Ce e 4,7% da MA) possui adequabilidade ambiental acima de 50%. Dos atributos que favorecem sua presença, a altitude (para todos os biomas), a precipitação (Ce e Pa), diferenças de temperatura e uso e cobertura do solo (Ma e Pp) foram os mais importantes. Em nível local, animais apresentaram média de AV de 90Km2 em AP e 41Km2 em AM, uma diferença significativa (p<0,01) com áreas diretamente proporcionais ao percentual de áreas naturais na paisagem. Ainda, apesar dos padrões regulares de atividade não mostrarem grandes mudanças, o período de repouso foi significativamente maior (p<0,01) entre os animais AM (46% do dia) que em animais AP (25% do dia). Lobos-guarás de AP e AM não apresentaram grandes diferenças no deslocamento diário com média geral de 14km caminhados por dia, com comprimentos de passos de 1Km. Diferenças no comprimento de passo foram relacionadas à composição da diversidade de contato de classes da paisagem com a proporção de ambientes naturais no passo (quanto maior as variáveis, maior o passo). Passos menores refletem menor persistência de movimento interferindo no deslocamento diário. Com os resultados desse estudo identificou-se a MA e Pa muito importantes, mas o Ce como bioma mais adequado à espécie. Foram encontrados indícios de que a estrutura de suas AV, o uso da paisagem, as atividades e movimentação são afetados pela paisagem modificada. Isso pode comprometer a viabilidade populacional, interferindo na presença em uma área e refletindo no seu potencial de distribuição. As estratégias de manejo de uso do solo, e a recuperação e conexão de áreas adequadas são urgentes e necessárias para que o lobo-guará permaneça presente e funcional nas paisagens dos biomas brasileiros. / The maned wolf has an extensive distribution range throughout South America with Brazil holding the largest portion of this area. However, the species is presently under a vulnerable status due to natural habitats alteration especially from farming and ranching. This study aimed to observe in large scale the potential distribution area indicated by favorable environmental attributes and suitable habitats to its presence within the Brazilian biomes and further to investigate how the species respond to the landscape structure, evaluating the effects of human-modified landscapes on its spatial ecology, activity patterns and movements. Species distribution models were generated using Maxent with a database of presence-only locations from 2000 though 2015, of the Cerrado (Ce), Pantanal (Pa), the Atlantic Forest (AF), and the Pampas (Pp) biomes, and eleven uncorrelated environmental variables (topographic, climatic, and landscape-based). As for the spatial ecology, activity and movement analysis, GPS-based telemetry locations were used from animals inhabiting protected (PAs) and disturbed areas (DAs). Home range (HR) analysis was performed using the AKDE estimator and then associated with the landscape-classified image. The distribution models for the maned wolf showed a potential distribution area of 78% of the total biomes range. Despite the high proportion of suitable areas (Ce, 90%; Pa, 93%; AF, 65%, and Pp, 6%), only a small percentage of the biomes (4.4% for Ce and 4.7% for AF) presented values over 50% suitable. Concerning the attributes that favor its presence, the altitude (for all the biomes), the precipitation (Ce and Pa), the temperature differences and land use (AF and Pp) were the most important. At the local scale, maned wolves showed HR sizes (average) with significant differences (p<0.01) between the 90Km2 (PA) and 41Km2 (DA) with HR size directly related to the proportion of natural areas. Although the general activity patterns were not considerably different between PA and DA, the resting periods of DA\'s animals (46% of the day) were significantly different (p<0.01) than the period of PA\'s wolves (46% of the day). Animals did not show changes on the daily movement patterns, accounting with 14km in general average and 1km of average step length (no major differences as well). The variation on the step length was related to the association of the diversity of contacts between landscape classes with the proportion of natural classes at each step (as bigger the variable values, bigger the step). As a consequence of smaller steps, constancy of movement decreases. Considering the results, the AF and Pa outstand as very important biomes, however the Ce was indicated as the most suitable biome. Furthermore, the research indicated signs that the HR structure and the landscape use, besides the activity patterns and the movement are affected by altered landscapes. This might compromise the population viability, interfering directly on its presence in an area and affecting the species distribution. Thus, a proper land use management aiming the recovering of degraded habitats is an important strategy tor the maned wolf conservation, so the species can long last survive across the Brazilian biomes.

L’écologie du Desman des Pyrénées (Galemys pyrenaicus), mammifère semi-aquatique endémique de la péninsule ibérique et des Pyrénées, demeure encore très peu connue. Les objectifs de cette thèse, dans le cadre d’un Plan National d’Actions, ont été d’identifier les variables environnementales agissant sur la répartition de l’espèce à différentes échelles spatiales, en considérant sa détectabilité imparfaite (i.e. fausses absences et fausses présences). Une probabilité de détection élevée, mais spatialement hétérogène à l’échelle des Pyrénées françaises, a été mise en évidence. La distribution du Desman des Pyrénées s’est également révélée spatialement structurée et majoritairement influencée par des facteurs propres aux milieux aquatiques, mais en forte régression depuis les années 80. Ces résultats ont permis de proposer des mesures de conservation pour cette espèce menacée. / The ecology of the Pyrenean desman (Galemys pyrenaicus), a small semi-aquatic mammal endemic to the Iberian Peninsula and the Pyrenees, remains still largely unknown. The aim of this PhD thesis conducted within the framework of a National Action Plan was to identify the environmental variables influencing the Desman distribution at various spatial scales, by accounting for its imperfect detection (i.e. false absences and false presences). A high, but spatially heterogeneous at the French Pyrenees extent, probability of detection was highlighted. The distribution of the Pyrenean Desman was also emphasized to be spatially structured and mainly influenced by aquatic factors, but severely contracting for the last 25 years. These results enabled to suggest conservation measures for this endangered species.

L’Afrique centrale atlantique (ACA) englobe l’ensemble du domaine bas-guinéen, les îles du Golfe de Guinée et une partie de l’archipel afromontagnard. Plusieurs centres d’endémisme ont été identifiés en son sein et sont généralement considérés comme liés à la présence de refuges forestiers durant les périodes glaciaires. Cependant, l’origine de cet endémisme, sa localisation et les méthodes permettant d’identifier ces centres restent controversées. La localisation de ces zones d’endémisme et des plantes rares qu’elles abritent, est pourtant un prérequis indispensable pour la mise en place de politiques cohérentes de conservation et demeure une priorité pour les organisations privées, institutionnelles ou gouvernementales actives dans la gestion et le maintien durable de la biodiversité.<p><p>Cette étude phytogéographique porte sur la famille des Orchidaceae et est basée sur l’analyse de la distribution des taxons endémiques de l’ACA. Elle s’appuie sur un jeu de données original résultant d’un effort d’échantillonnage important au Cameroun et d’un travail d’identification et de localisation de spécimens dans les principaux herbaria européens abritant des collections d’ACA. Durant cette étude, (i) nous avons tout d’abord identifié ces taxons endémiques et documenté leur distribution au travers de plusieurs contributions taxonomiques et floristiques, (ii) nous nous sommes ensuite intéressé aux nouvelles méthodes permettant d’analyser ces données d’herbier de plantes rares et donc pauvrement documentées, testant aussi l’intérêt des Orchidaceae comme marqueurs chorologiques, et finalement, appliquant ces méthodes à notre jeu de données, (iii) nous avons délimité des centres d’endémisme et identifié les territoires phytogéographiques des Orchidaceae en ACA.<p><p>(i) Une révision taxonomique des genres Chamaeangis Schltr. et Stolzia Schltr. a été réalisée respectivement. Sept nouveaux taxons ont été décrits: Angraecum atlanticum Stévart & Droissart, Chamaeangis spiralis Stévart & Droissart, Chamaeangis lecomtei (Finet) Schltr. var. tenuicalcar Stévart & Droissart, Polystachya engogensis Stévart & Droissart, Polystachya reticulata Stévart & Droissart, Stolzia repens (Rolfe) Summerh var. cleistogama Stévart, Droissart & Simo et Stolzia grandiflora P.J.Cribb subsp. lejolyana Stévart, Droissart & Simo. Plusieurs notes taxonomiques, phytogéographiques et écologiques supplémentaires ont également été redigées. Au total, nous avons identifié 203 taxons d’Orchidaceae endémiques d’ACA parmi lesquels 193 sont pris en compte pour l’étude des patrons d’endémisme.<p><p>(ii) Au Cameroun, les patrons de distribution des Orchidaceae et des Rubiaceae endémiques d’ACA ont été étudiés conjointement. Des méthodes de rééchantillonnage des données (raréfaction) ont été appliquées pour calculer des indices de diversité et de similarité. Elles ont permis de corriger les biais liés à la variation de l’effort d’échantillonnage. Un gradient de continentalité a été observé, les parties côtières étant les plus riches en taxons endémiques d’ACA. Contrairement à la région du Mont Cameroun et aux massifs de Kupe/Bakossi qui ont connu une attention particulière des politiques et des scientifiques, la partie côtière du sud Cameroun, presque aussi riche, reste mal inventoriée pour plusieurs familles végétales.<p><p>Cette analyse à l’échelle du Cameroun a également permis de comparer les patrons d’endémisme des Orchidaceae et des Rubiaceae. Les différences observées seraient principalement dues à la présence d’Orchidaceae terrestres dans les végétations basses et les prairies montagnardes de la dorsale camerounaise alors que les Rubiaceae sont généralement peu représentées dans ces habitats. Au sein des habitats forestiers, la concordance entre les patrons d’endémisme des Orchidaceae et des Rubiaceae remet en question l’utilisation des capacités de dispersion des espèces comme critère pour choisir les familles permettant l’identification des refuges forestiers et semble ainsi confirmer la pertinence de l’utilisation des Orchidaceae comme marqueur chorologique.<p><p>La distribution potentielle a été utilisée pour étudier en détail l’écologie, la distribution et le statut de conservation de Diceratostele gabonensis Summerh. une Orchidaceae endémique de la région guinéo-congolaise uniquement connue d’un faible nombre d’échantillons. Cette méthodologie semble appropriée pour compléter nos connaissances sur la distribution des espèces rares et guider les futurs inventaires en Afrique tropicale.<p><p>(iii) En ACA, les Orchidaceae permettent d’identifier plusieurs centres d’endémisme qui coïncident généralement avec ceux identifiés précédemment pour d’autres familles végétales. Ces constats supportent aussi l’utilisation des Orchidaceae comme marqueur chorologique. La délimitation des aires d’endémisme des Orchidaceae a ainsi permis de proposer une nouvelle carte phytogéographique de l’ACA. Les éléments phytogéographiques propres à chacune des dix phytochories décrites ont été identifiés et leurs affinités floristiques discutées. Les résultats phytogéographiques obtenus (a) soutiennent l’existence d’une barrière phytogéographique matérialisée par la rivière Sanaga entre les deux principaux centres et aires d’endémisme de l’ACA, (b) étendent l’archipel afromontagnard situé principalement au Cameroun au plateau de Jos (Nigeria) et (c) montrent l’importance de la chaîne montagneuse morcelée Ngovayang-Mayombe pour la distribution de l’endémisme en ACA. Cette chaîne de montagne, qui s’étend le long des côtes de l’océan du sud Cameroun au Congo-Brazzaville et qui correspond à plusieurs refuges forestiers identifiés par de nombreux auteurs, est ici considérée comme une seule aire d’endémisme morcelée./<p>Atlantic central Africa (ACA) covers the Lower Guinean Domain, the four islands of the Gulf of Guinea and a part of the afromontane archipelago. Different centres of endemism have been identified into this area and are usually considered as related to glacial forest refuges. However, the origin of this endemism, the localization of the centres and the methods employed to identify these centres are subject to debate. Yet, the localization of these centres of endemism and the identification of the rare plants they harbor is an essential prerequisite to setting up rational conservation policies, and remains a priority for private, institutional and governmental organizations which are dealing with the sustainable management of biodiversity.<p><p>This phytogeographical study focuses on Orchidaceae and analyses the distribution of the taxa endemic to ACA. We use an original dataset resulting from an important sampling efforts and the identification of specimens coming from all the principal herbaria where collections from ACA are housed. During this study, (i) we first identified the taxa endemic to ACA and documented their distribution through several taxonomic and floristic contributions, (ii) we used and developed new methods allowing to correct for sampling bias associated with the use of rare and poorly documented taxa, testing at the same time the use of Orchidaceae as chorological markers, and finally, applying these methods to our dataset, (iii) we delimited the centres of endemism and identified the phytogeographical territories of Orchidaceae in ACA.<p><p>(i) A taxonomic revision of Chamaeangis Schltr. and Stolzia Schltr. respectively was carried out. Seven new taxa were described: Angraecum atlanticum Stévart & Droissart, Chamaeangis spiralis Stévart & Droissart, Chamaeangis lecomtei (Finet) Schltr. var. tenuicalcar Stévart & Droissart, Polystachya engogensis Stévart & Droissart, Polystachya reticulata Stévart & Droissart, Stolzia repens (Rolfe) Summerh var. cleistogama Stévart, Droissart & Simo and Stolzia grandiflora P.J.Cribb subsp. lejolyana Stévart, Droissart & Simo. Several additional taxonomic, phytogeographical and ecological notes were also published. We finally identified 203 Orchidaceae taxa endemic to ACA, among which 193 were used to study the patterns of endemism.<p><p>(ii) In Cameroon, the distribution patterns of both Orchidaceae and Rubiaceae endemic to ACA were studied. Subsampling methods (rarefaction) were applied to calculate diversity and similarity indices and to correct potential bias associated with heterogeneous sampling intensity. A gradient of continentality was confirmed in Cameroon, the coastal part being the richest in taxa endemic to ACA. The Cameroon Mountain and the Kupe/Bakossi mountain massifs have received a great consideration of politics and scientists. On the contrary, the Southern coastal part of Cameroon, though almost as rich as the Northern part, remains poorly known for several plant families.<p>This analysis also allowed us to compare patterns of endemism of Orchidaceae and Rubiaceae. The differences observed could be mainly due to the terrestrial habit of some Orchidaceae, which are only found in the grasslands of the highest part of the Cameroonian volcanic line where endemic Rubiaceae are rare. Within forest habitats, the concordance between the patterns of endemism of Orchidaceae and Rubiaceae question the widespread use of dispersal ability as a selection criterion for the families used to identify forest refuges. This also confirms the relevance of Orchidaceae as chorological marker.<p><p>Species distribution modelling was used of an in depth study of the ecology, the distribution and the conservation status of Diceratostele gabonensis Summerh. an Orchidaceae endemic to the Guineo-Congolian regional centre of endemism which is only known from very few collections. This method is proved to be appropriate to complete our knowledge on the distribution of rare plant species and to guide the future inventories in tropical Africa.<p><p>(iii) In ACA, an analysis of the distribution of endemic Orchidaceae confirmed the presence and location of several centres of endemism previously identified on the basis of other plant families. This result again supports the use of Orchidaceae as a chorological marker. The chorological study of the endemic Orchidaceae allowed us to propose a new phytogeographical map for ACA. Phytogeographical elements for each of the ten phytochoria described were identified and their floristic affinities were also discussed. Our results (a) support the existence of a phytogeographical barrier, materialized by the Sanaga River, between the two main centres and area of endemism of the ACA, (b) extend the limits of the afromontane archipelago to the Jos Plateau in Nigeria and (c) show the importance of the Ngovayang-Mayombe line to explain the distribution of endemism in ACA. This mountainous line, stretching along the ocean coast from Southern Cameroon to Congo-Brazzaville, corresponds to several forest refuges identified by many authors, and is here considered as an unique but discontinuous area of endemism.<p><p><p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

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