Ecologia e evolução de cactaceae nas Américas

Compreender como processos ecológicos e evolutivos atuam é fundamental para entender os padrões globais de diversidade e para prever suas variações perante mudanças climáticas e conversão da paisagem natural. Processos ecológicos envolvem a dispersão e a relação dos organismos com o meio ambiente e com outros seres vivos. Processos evolutivos influenciam a história dos organismos, principalmente através do equilíbrio entre especiação/extinção e outros mecanismos de mudança molecular. Na macroescala, esses processos, em conjunto, determinarão os táxons disponíveis para dispersar e colonizar certos ambientes, através do espaço e do tempo, contribuindo para configuração de padrões globais de diversidade e de composição. Entender como os organismos são influenciados por fatores bióticos, abióticos e históricos exige uma abordagem analítica integrativa considerando diferentes níveis hierárquicos. O objetivo desta tese foi investigar a contribuição de processos ecológicos e evolutivos na formação de padrões atuais de co-ocorrência de Cactaceae nas Americas. Para tanto, verifiquei a contribuição de processos determinísticos e estocásticos na distribuição e na estruturação espacial de cactos no continente americano e explorei composições e diversidades taxonômica e filogenéticas. A partir de dados de presença/ausência e gradientes climáticos, apliquei a Modelagem Hierárquica de Comunidades de Espécies (HMSC) em uma abordagem de validação cruzada quádrupla e avaliei mudanças nas co-ocorrências simulando riqueza e composição com extremos de gradientes climáticos (capítulo 2). Avaliei estrutura e composição filogenética através do índice de parentesco líquido (NRI) e do índice de parentesco mais próximo (NTI), bem como através da variação na composição filogenética entre assembleias a partir das coordenadas principais da estrutura filogenética (PCPS) (capítulo 3). Analisei a riqueza de gêneros e a diversidade alfa filogenética em centros de diversidade através de modelos mistos. Os dados sugerem uma relação complexa dos cactos com gradientes climáticos A ocorrência de cactáceas refletiu padrões não aleatórios associados à variação espacial do clima nas Américas. Tolerâncias específicas de gêneros para extremos e sazonalidade de temperatura e precipitação estão ligadas à forma corporal e ao parentesco dos cactos. As simulações sugeriram aumento de riqueza em extremos opostos dos gradientes e mudanças na composição de acordo com extremos climáticos opostos. Padrões filogenéticos aleatórios e agrupados prevaleceram em todos os centros de diversidade, enquanto a repulsão foi restrita a algumas regiões da América do Sul. A composição filogenética variou entre as Américas do Norte e do Sul por causa da divisão da subfamília Cactoideae e do turnover dos gêneros entre os centros de diversidade. O estudo representa um passo inicial para evidenciar a influência de processos determinísticos e estocásticos na co-ocorrência de Cactaceae. Ele fornece informações para orientar a conservação de Cactaceae nas Américas, à medida que auxilia a direcionar esforços baseados em como as formas corporais respondem ao clima e seu consequente efeito sobre a distribuição e a estruturação de diferentes dimensões da diversidade. A distribuição da repulsão nas Américas coincide com a distribuição disjunta das florestas secas. A distribuição de padrões de agrupamento se sobrepõe à co-ocorrência de linhagens radiadas e isoladas, sugerindo que as mudanças de habitat desempenham um papel na diversificação e distribuição de Cactaceae.Comprehending how ecological and evolutionary processes work is critical to understanding global patterns of diversity and predicting their variations in the face of climate change and natural landscape conversion. Ecological processes involve the dispersal and relationship of organisms with the environment and other living beings. Evolutionary processes influence the history of organisms, mainly through the balance between speciation/extinction and other mechanisms of molecular change. At the macroscale, these processes together will determine the available taxa to disperse and colonize certain environments, through space and time, contributing to the setting of global patterns of diversity and composition. Understanding how organisms are influenced by biotic, abiotic and historical factors requires an integrative analytical approach considering different hierarchical levels. The objective of this thesis was to investigate the contribution of ecological and evolutionary processes in shaping current patterns of co-occurrence of Cactaceae in the Americas. To this end, I verified the contribution of deterministic and stochastic processes in the distribution and spatial structuring of cacti in the American continent, and explored taxonomic and phylogenetic compositions and diversities. From presence/absence data and climate gradients, I applied the Hierarchical Species Communities Modelling (HMSC) in a four-way cross-validation approach and explored changes in the co-occurrences simulating richness and composition with extremes of climatic gradients (chapter 2). I evaluated phylogenetic structure and composition through the net related index (NRI) and the nearest taxon index (NTI), and analyzed variation in the phylogenetic composition between assemblages based on Principal Coordinates of the Phylogenetic Structure (PCPS) (chapter 3). I analyzed genera richness and phylogenetic structure among diversity centers using mixed models. The data suggest an overall complex response of cacti to climate gradients. Occurrences of cacti reflected non-random patterns associated with spatial climate variation in the Americas. Genera-specific tolerances for extremes and seasonality of both temperature and precipitation were linked to growth form and cacti phylogenetic relatedness. Simulations suggested increase of richness in opposite extremes of the gradients and with composition changing according with opposing climatic extremes. Random and clustered phylogenetic patterns prevailed in all centers of diversity, while repulsion was restricted to some regions of South America. Phylogenetic composition varied between North and South America because of division of subfamily Cactoideae and genera turnover between diversity centers. The study represents an initial step to highlight the influence of deterministic and stochastic processes on the co-occurrence of Cactaceae. It provides information to guide the conservation of Cactaceae in the Americas as it helps to direct efforts based on how body shapes respond to climate and its effect on the distribution and structuring of different dimensions of diversity. The distribution of overdispersion in the Americas coincides with the disjunct distribution of dry forests. The distribution of clustering patterns overlaps with the co-occurrence of isolated and in situ radiated lineages, suggesting that habitat changes play a role in Cactaceae diversification and distribution

Produção de material didático para ensino e aprendizagem de conceitos de ecologia utilizando as cactáceas como modelo

O reconhecimento da fauna e da flora brasileira é fundamental para orientar o avanço de iniciativas que promovam a preservação e a conservação da diversidade, tanto de ecossistemas naturais e dos organismos neles inseridos, como das funções ecológicas resultantes das interações que os sustentam no espaço e no tempo. Para que esse conhecimento da diversidade brasileira permeie a sociedade faz-se necessário que o conhecimento científico esteja acessível tanto aos processos de ensino e aprendizagem/educacionais (processos iniciais de formação) como aos políticos tomadores de decisão e os mecanismos que fundamentam suas ações. Nesse sentido, o presente trabalho propõe-se produzir um guia ecológico de cactos como resultado do meu processo de formação e de pesquisa documental realizada através de análise exploratória em livros de Ecologia e análise de conteúdo na Base Nacional Comum Curricular, no Referencial Gaúcho e em imagens e conteúdos de unidades de livros didáticos.The recognition of the Brazilian fauna and flora is essential to guide the advancement of initiatives promoting the preservation and conservation of diversity, both of natural ecosystems and the organisms within them, as well as the ecological functions resulting from the interactions that sustain them in space and in the time. For this knowledge of Brazilian diversity to permeate society, it is necessary that scientific knowledge to be accessible both to teaching and learning/educational processes (initial training processes) as well as to political decision-makers and the mechanisms that underlie their actions. In this sense, the present work proposes to produce an ecological guide for cacti as a result of my training process and documental research carried out through exploratory analysis in Ecology books and content analysis in the Base Nacional Comum Curricular, Referencial Curricular Gaúcho, and in images and contents of textbook units

Ecologia e evolução de cactaceae nas Américas

Compreender como processos ecológicos e evolutivos atuam é fundamental para entender os padrões globais de diversidade e para prever suas variações perante mudanças climáticas e conversão da paisagem natural. Processos ecológicos envolvem a dispersão e a relação dos organismos com o meio ambiente e com outros seres vivos. Processos evolutivos influenciam a história dos organismos, principalmente através do equilíbrio entre especiação/extinção e outros mecanismos de mudança molecular. Na macroescala, esses processos, em conjunto, determinarão os táxons disponíveis para dispersar e colonizar certos ambientes, através do espaço e do tempo, contribuindo para configuração de padrões globais de diversidade e de composição. Entender como os organismos são influenciados por fatores bióticos, abióticos e históricos exige uma abordagem analítica integrativa considerando diferentes níveis hierárquicos. O objetivo desta tese foi investigar a contribuição de processos ecológicos e evolutivos na formação de padrões atuais de co-ocorrência de Cactaceae nas Americas. Para tanto, verifiquei a contribuição de processos determinísticos e estocásticos na distribuição e na estruturação espacial de cactos no continente americano e explorei composições e diversidades taxonômica e filogenéticas. A partir de dados de presença/ausência e gradientes climáticos, apliquei a Modelagem Hierárquica de Comunidades de Espécies (HMSC) em uma abordagem de validação cruzada quádrupla e avaliei mudanças nas co-ocorrências simulando riqueza e composição com extremos de gradientes climáticos (capítulo 2). Avaliei estrutura e composição filogenética através do índice de parentesco líquido (NRI) e do índice de parentesco mais próximo (NTI), bem como através da variação na composição filogenética entre assembleias a partir das coordenadas principais da estrutura filogenética (PCPS) (capítulo 3). Analisei a riqueza de gêneros e a diversidade alfa filogenética em centros de diversidade através de modelos mistos. Os dados sugerem uma relação complexa dos cactos com gradientes climáticos A ocorrência de cactáceas refletiu padrões não aleatórios associados à variação espacial do clima nas Américas. Tolerâncias específicas de gêneros para extremos e sazonalidade de temperatura e precipitação estão ligadas à forma corporal e ao parentesco dos cactos. As simulações sugeriram aumento de riqueza em extremos opostos dos gradientes e mudanças na composição de acordo com extremos climáticos opostos. Padrões filogenéticos aleatórios e agrupados prevaleceram em todos os centros de diversidade, enquanto a repulsão foi restrita a algumas regiões da América do Sul. A composição filogenética variou entre as Américas do Norte e do Sul por causa da divisão da subfamília Cactoideae e do turnover dos gêneros entre os centros de diversidade. O estudo representa um passo inicial para evidenciar a influência de processos determinísticos e estocásticos na co-ocorrência de Cactaceae. Ele fornece informações para orientar a conservação de Cactaceae nas Américas, à medida que auxilia a direcionar esforços baseados em como as formas corporais respondem ao clima e seu consequente efeito sobre a distribuição e a estruturação de diferentes dimensões da diversidade. A distribuição da repulsão nas Américas coincide com a distribuição disjunta das florestas secas. A distribuição de padrões de agrupamento se sobrepõe à co-ocorrência de linhagens radiadas e isoladas, sugerindo que as mudanças de habitat desempenham um papel na diversificação e distribuição de Cactaceae.Comprehending how ecological and evolutionary processes work is critical to understanding global patterns of diversity and predicting their variations in the face of climate change and natural landscape conversion. Ecological processes involve the dispersal and relationship of organisms with the environment and other living beings. Evolutionary processes influence the history of organisms, mainly through the balance between speciation/extinction and other mechanisms of molecular change. At the macroscale, these processes together will determine the available taxa to disperse and colonize certain environments, through space and time, contributing to the setting of global patterns of diversity and composition. Understanding how organisms are influenced by biotic, abiotic and historical factors requires an integrative analytical approach considering different hierarchical levels. The objective of this thesis was to investigate the contribution of ecological and evolutionary processes in shaping current patterns of co-occurrence of Cactaceae in the Americas. To this end, I verified the contribution of deterministic and stochastic processes in the distribution and spatial structuring of cacti in the American continent, and explored taxonomic and phylogenetic compositions and diversities. From presence/absence data and climate gradients, I applied the Hierarchical Species Communities Modelling (HMSC) in a four-way cross-validation approach and explored changes in the co-occurrences simulating richness and composition with extremes of climatic gradients (chapter 2). I evaluated phylogenetic structure and composition through the net related index (NRI) and the nearest taxon index (NTI), and analyzed variation in the phylogenetic composition between assemblages based on Principal Coordinates of the Phylogenetic Structure (PCPS) (chapter 3). I analyzed genera richness and phylogenetic structure among diversity centers using mixed models. The data suggest an overall complex response of cacti to climate gradients. Occurrences of cacti reflected non-random patterns associated with spatial climate variation in the Americas. Genera-specific tolerances for extremes and seasonality of both temperature and precipitation were linked to growth form and cacti phylogenetic relatedness. Simulations suggested increase of richness in opposite extremes of the gradients and with composition changing according with opposing climatic extremes. Random and clustered phylogenetic patterns prevailed in all centers of diversity, while repulsion was restricted to some regions of South America. Phylogenetic composition varied between North and South America because of division of subfamily Cactoideae and genera turnover between diversity centers. The study represents an initial step to highlight the influence of deterministic and stochastic processes on the co-occurrence of Cactaceae. It provides information to guide the conservation of Cactaceae in the Americas as it helps to direct efforts based on how body shapes respond to climate and its effect on the distribution and structuring of different dimensions of diversity. The distribution of overdispersion in the Americas coincides with the disjunct distribution of dry forests. The distribution of clustering patterns overlaps with the co-occurrence of isolated and in situ radiated lineages, suggesting that habitat changes play a role in Cactaceae diversification and distribution

Land use explains the distribution of threatened new world amphibians better than climate

Background: We evaluated the direct and indirect influence of climate, land use, phylogenetic structure, species richness and endemism on the distribution of New World threatened amphibians. Methodology/Principal Findings: We used the WWF’s New World ecoregions, the WWFs amphibian distributional data and the IUCN Red List Categories to obtain the number of threatened species per ecoregion. We analyzed three different scenarios urgent, moderate, and the most inclusive scenario. Using path analysis we evaluated the direct and indirect effects of climate, type of land use, phylogenetic structure, richness and endemism on the number of threatened amphibians in New World ecoregions. In all scenarios we found strong support for direct influences of endemism, the cover of villages and species richness on the number of threatened species in each ecoregion. The proportion of wild area had indirect effects in the moderate and the most inclusive scenario. Phylogenetic composition was important in determining the species richness and endemism in each ecoregion. Climate variables had complex and indirect effects on the number of threatened species. Conclusion/Significance: Land use has a more direct influence than climate in determining the distribution of New World threatened amphibians. Independently of the scenario analyzed, the main variables influencing the distribution of threatened amphibians were consistent, with endemism having the largest magnitude path coefficient. The importance of phylogenetic composition could indicate that some clades may be more threatened than others, and their presence increases the number of threatened species. Our results highlight the importance of man-made land transformation, which is a local variable, as a critical factor underlying the distribution of threatened amphibians at a biogeographic scale

Land use explains the distribution of threatened new world amphibians better than climate

Background: We evaluated the direct and indirect influence of climate, land use, phylogenetic structure, species richness and endemism on the distribution of New World threatened amphibians. Methodology/Principal Findings: We used the WWF’s New World ecoregions, the WWFs amphibian distributional data and the IUCN Red List Categories to obtain the number of threatened species per ecoregion. We analyzed three different scenarios urgent, moderate, and the most inclusive scenario. Using path analysis we evaluated the direct and indirect effects of climate, type of land use, phylogenetic structure, richness and endemism on the number of threatened amphibians in New World ecoregions. In all scenarios we found strong support for direct influences of endemism, the cover of villages and species richness on the number of threatened species in each ecoregion. The proportion of wild area had indirect effects in the moderate and the most inclusive scenario. Phylogenetic composition was important in determining the species richness and endemism in each ecoregion. Climate variables had complex and indirect effects on the number of threatened species. Conclusion/Significance: Land use has a more direct influence than climate in determining the distribution of New World threatened amphibians. Independently of the scenario analyzed, the main variables influencing the distribution of threatened amphibians were consistent, with endemism having the largest magnitude path coefficient. The importance of phylogenetic composition could indicate that some clades may be more threatened than others, and their presence increases the number of threatened species. Our results highlight the importance of man-made land transformation, which is a local variable, as a critical factor underlying the distribution of threatened amphibians at a biogeographic scale

Land Use Explains the Distribution of Threatened New World Amphibians Better than Climate

<div><p>Background</p><p>We evaluated the direct and indirect influence of climate, land use, phylogenetic structure, species richness and endemism on the distribution of New World threatened amphibians.</p><p>Methodology/Principal Findings</p><p>We used the WWF’s New World ecoregions, the WWFs amphibian distributional data and the IUCN Red List Categories to obtain the number of threatened species per ecoregion. We analyzed three different scenarios urgent, moderate, and the most inclusive scenario. Using path analysis we evaluated the direct and indirect effects of climate, type of land use, phylogenetic structure, richness and endemism on the number of threatened amphibians in New World ecoregions. In all scenarios we found strong support for direct influences of endemism, the cover of villages and species richness on the number of threatened species in each ecoregion. The proportion of wild area had indirect effects in the moderate and the most inclusive scenario. Phylogenetic composition was important in determining the species richness and endemism in each ecoregion. Climate variables had complex and indirect effects on the number of threatened species.</p><p>Conclusion/Significance</p><p>Land use has a more direct influence than climate in determining the distribution of New World threatened amphibians. Independently of the scenario analyzed, the main variables influencing the distribution of threatened amphibians were consistent, with endemism having the largest magnitude path coefficient. The importance of phylogenetic composition could indicate that some clades may be more threatened than others, and their presence increases the number of threatened species. Our results highlight the importance of man-made land transformation, which is a local variable, as a critical factor underlying the distribution of threatened amphibians at a biogeographic scale.</p></div

Hypothetical causal model establishing all possible and plausible causal connections between variables.

<p>Hypothetical causal model establishing all possible and plausible causal connections between variables.</p

Maps showing the spatial pattern of richness of amphibian species, endemism and the number of threatened amphibian species according to the three different scenarios per ecoregion: the urgent scenario, containing only CR species and those EW and EX, the moderate scenario containing all EN species and those at threat categories higher than EN (i.e. CR, EW, and EX), and the most inclusive scenario, which included all VU species and those at higher threat categories.

<p>Maps showing the spatial pattern of richness of amphibian species, endemism and the number of threatened amphibian species according to the three different scenarios per ecoregion: the urgent scenario, containing only CR species and those EW and EX, the moderate scenario containing all EN species and those at threat categories higher than EN (i.e. CR, EW, and EX), and the most inclusive scenario, which included all VU species and those at higher threat categories.</p

Correlation values of each climatic variable with the two first axes of the principal components analysis. M indicates mean values and R indicates range values.

<p>Correlation values of each climatic variable with the two first axes of the principal components analysis. M indicates mean values and R indicates range values.</p

Correlation scatter plot for amphibian phylogenetic clades showing correlation values with three Principal Coordinates of Phylogenetic Structure (PCPS 1, PCPS2 and PCPS3) axes.

<p>Each point represents an amphibian genus. Genera are grouped within higher clades represented by different symbols.</p