Orientador: Luiz Fernando Rolim de Almeida / Resumo: A implantação de sistemas de restauração possibilita o restabelecimento da estrutura e funcionamento de ecossistemas degradados. Além disso, alta diversidade taxonômica e funcional dos sistemas de restauração garante a performance e estabilidade de ecossistemas restaurados. A efetividade e monitoramento dos sistemas de restauração são quantificados por variáveis alométricas, porém, desconsideram-se variáveis relacionadas a aquisição de carbono e atividade fotoquímica. Dessa forma, o objetivo deste estudo foi o avaliar as respostas ecofisiológicas de plantas em diferentes sistemas de restauração florestal e avaliar se a capacidade de perda de água e reidratação de espécies de crescimento rápido e lento favorece o estabelecimento e desenvolvimento de sistemas de restauração com estrutura e diversidade de espécies contratantes. Portanto, avaliamos, durante um ano, variáveis relacionadas à disponibilidade de água no solo e ambiente, estrutura dos sistemas de plantio, relações hídricas, atividade fotoquímica e aquisição e acúmulo de carbono nas folhas, em 7 espécies (divididas em espécies de crescimento rápido e lento) pertencentes a três sistemas de restauração: plantio de alta diversidade, sistema agroflorestal e consórcio madeira e lenha, estes sistemas estão implantados em dois tipos de solo: Nitossolo Vermelho (Área 1 – solo argiloso) e Argissolo Vermelho Amarelo (Área 2 – solo arenoso). Os resultados indicaram que sistemas implantados na área 1 apresentaram maior eficiência ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The restoration systems implantation enables the restoration of degraded ecosystems structure and functioning. In addition, restoration systems high taxonomic and functional diversity guarantees restored ecosystems performance and stability. The restoration systems effective-ness and monitoring are quantified by allometric variables, however, variables related to carbon acquisition and photochemical activity are disregarded. Thus, the aim study was to evaluate the ecophysiological responses of plants in different forest restoration systems and to evaluate if the water loss and rehydration capacity of fast and slow growth species favors the establishment and development of systems with contracting structure and species diversity. Therefore, we evaluated, for one year, variables related to the soil and environment water availability, planting systems structure, water relations, photochemical activity and carbon acquisition in leaves, in 7 species (divided into fast and slow growth species). These systems are implanted in two soils types: fertile loamy Ultisol (Site 1) and sandy Alfisol soil (Site 2). The results indicated that systems implanted in site 1 showed higher photosynthetic efficiency and carbon accumulation during water deficiency periods. The wood and wood consortium presented lower complexity in the structure and higher photosynthetic efficiency in times with low water availability in the soil. The mixed plantation using commercial timber and firewood tree species o... (Complete abstract click electronic access below) / Doutor

Les écosystèmes prairiaux alpestres sont supposés être très sensibles au changement climatique. Cependant leur long historique fait de variation du climat et de multiples siècles d'utilisation des terres peut avoir sélectionné des mécanismes de résilience écologique à la variabilité climatique et aux stress climatiques extrêmes. Nous avons utilisé un dispositif expérimental de grande envergure pour explorer les mécanismes de réponses des prairies subalpines à une combinaison d’extrêmes météorologiques hivernaux (fonte des neiges précoce) et estivaux (sécheresse) en fonction de la composition fonctionnelle des communautés végétales et des pratiques de gestion des terres. La composition fonctionnelle des prairies a été manipulée à l’aide d’assemblages de trois espèces de poacées en différentes abondances relatives, représentant in fine un gradient d’utilisation des ressources allant de la conservation à l'exploitation. De manière générale, la composition fonctionnelle a été le principal déterminant de tous les paramètres observés pour la performance individuelle des plantes, les réponses intraspécifiques des plantes, la décomposition de la litière et les processus de recyclage de l'azote. Le fonctionnement des écosystèmes prairiaux dominés par des plantes conservatrices a été remarquablement résistant aux traitements climatiques extrêmes, tandis que les écosystèmes prairiaux dominés par des plantes plus exploitatrices ont été plus résilients. Les pratiques de gestion ont modulé ces réponses et plus particulièrement dans le cas des communautés exploitatrices. Les allocations souterraines aux réserves glucidiques et aux pools d'azote microbiens ont été identifiées comme deux mécanismes clés sous-tendant les réponses des communautés résilientes. Néanmoins, des répercussions à plus long terme du changement climatique pourraient être observées, causées par un épuisement successif des réserves végétales et une diminution des retours azotés vers le sol via les processus de décomposition. / Alpine grassland ecosystems are presumed to be highly sensitive to climate change, yet their long history of climate variability, and multiple centuries of land use may have selected for mechanisms of ecological resilience to climate variability and climate extremes. We used a large experimental design to explore patterns and mechanisms for responses of subalpine grasslands to combined winter (snow removal) and summer (drought) weather extremes depending on plant functional composition and management. Plant functional composition was manipulated by establishing grass mixtures with three species representing a conservation to exploitation gradient planted at varying relative abundances. Overall, functional composition was the primary determinant of all observed parameters for plant individual performance, intraspecific plant trait responses, litter decomposition and nitrogen recycling processes. The functioning of grassland ecosystems dominated by conservative plants was remarkably resistant to extreme weather treatments, while grassland ecosystems dominated by more exploitative plants were more resilient. Management altered these responses mostly in the case of exploitative communities. Belowground allocation to carbohydrate reserves and to microbial nitrogen pools were identified as two key mechanisms underpinning these resilient responses. Longer-term impacts of climate change may however unfold through the exhaustion of plant reserves and decreasing nitrogen returns to soils via decomposition process.

L’objectif général de cette thèse est de déterminer le rôle de l’exclusion compétitive, du filtrage environnemental et des limites de dispersion dans la distribution des espèces de fourmis de la litière en forêt guyanaise. Pour cela, nous avons évalué comment la diversité des assemblages de fourmis varie le long de gradients environnementaux et géographiques, en considérant les trois facettes de la diversité (i.e. taxonomique, phylogénétique et fonctionnelle) à différentes échelles spatiales. Des patrons observés de structure fonctionnelle et phylogénétique plus faibles qu’attendus au hasard suggèrent que le filtrage environnemental agit sur la distribution des espèces à l’échelle du site de récolte. En revanche, l’hypothèse d’une sur-dispersion fonctionnelle et/ou phylogénétique entre espèces qui co-occurrent localement résultant de l’exclusion d’espèces similaires n’est pas soutenue par nos résultats. A l’échelle régionale, nos résultats montrent que les communautés de fourmis sont fortement structurées par les variations environnementales. La distance spatiale influence également la distribution des espèces de fourmis à travers la région. D’après l’ensemble de nos résultats, le filtrage environnemental est la force majeure de structuration des assemblages d’espèces de fourmis en forêt guyanaise, tant à l’échelle locale qu’à l’échelle régionale. Les espèces sont réparties de manière fragmentaire sur le territoire, en réponse aux variations environnementales. Les patrons de diversité sont également influencés par la distance spatiale à l’échelle régionale, résultant en un turnover dans la composition spécifique des assemblages de fourmis entre localités éloignées. / The overall aim of this thesis is to determine the role of competitive exclusion, environmental filtering and dispersal limitation on the distribution of leaf-litter ant species in French Guianese forest. To this end, we evaluated how the diversity of ant communities varies along environmental and geographic gradients, using the three facets of diversity (i.e. taxonomic, phylogenetic and functional dimensions) at different spatial scales. Observed patterns of functional and phylogenetic structure lower than expected by chance suggest that environmental filtering acts on the distribution of ant species at the scale of sampled site. In contrast, the hypothesis of functional and/or phylogenetic overdispersion between locally co-occurring species resulting from the exclusion of similar species is not supported by our results. At the regional scale, our results show that ant communities are strongly structured by environmental variations. Spatial distance also influences the distribution of ant species throughout the region. Taken together, our results suggest that environmental filtering is the main driver structuring communities of ant species in French Guianese rainforest, both at local and regional scales. Species are distributed in a patchy way throughout the region, in response to environmental variations. Patterns of diversity are also influenced by the spatial distance at the regional scale, leading to a turnover in species composition of ant communities between distant areas.

The objective of this work was to understand microbial population density and diversity, both spatially and temporally, in wetland mesocosms to gain a better fundamental understanding for use in the optimization and design of constructed wetlands (CWs). A standardized community level physiological profiling (CLPP) data analysis protocol was adapted and utilized for CW mesocosms. A new one-dimensional metric was developed to track community divergence using BIOLOGTM ECO plate data. The method proved easy to use, did not require a background in multivariate statistics, and accurately described community divergence in mesocosm systems. To study mesocosm biofilm-bound bacterial communities an appropriate detachment protocol was required. Various shaking protocols were evaluated for their effectiveness in the detachment of bacteria from mesocosm pea gravel, with a focus on detachment of viable and representative bacterial communities. A protocol based on mechanical shaking with buffer and enzymes was identified as an optimal approach and used further in this study. The bacterial communities associated with the interstitial water, pea gravel media, and rhizospheric regions from both planted and unplanted CW mesocosms were profiled using the CLPP method and compared. Vertical community stratification was observed for all mesocosm systems. Rhizospheric communities were found to be significantly more active than their gravel-associated counterparts, suggesting that although rhizospheric bacteria were less abundant in the mesocosms they may play a more significant role in the removal and fate of water born contaminants. The start-up dynamics of CW mesocosms was investigated using the CLPP and standard CW characterization methods over an eight month period. All mesocosms showed a steep increase in interstitial community divergence until day 75-100, at which point a steady-state was reached. The interstitial communities were also characterized in terms of similarity based on experimental design treatments (planted/unplanted and origin of seeding inoculum). Four stages were identified during the start-up consisting of an initial stage where mesocosm communities were differentiated based on origin of the inoculum, a period where adjustments and shifts occurred in all mesocosm, a time where all mesocosm communities were quite similar, and a final state where community differentiations were made based plant presence in the mesocosms.

The objective of this work was to understand microbial population density and diversity, both spatially and temporally, in wetland mesocosms to gain a better fundamental understanding for use in the optimization and design of constructed wetlands (CWs). A standardized community level physiological profiling (CLPP) data analysis protocol was adapted and utilized for CW mesocosms. A new one-dimensional metric was developed to track community divergence using BIOLOGTM ECO plate data. The method proved easy to use, did not require a background in multivariate statistics, and accurately described community divergence in mesocosm systems. To study mesocosm biofilm-bound bacterial communities an appropriate detachment protocol was required. Various shaking protocols were evaluated for their effectiveness in the detachment of bacteria from mesocosm pea gravel, with a focus on detachment of viable and representative bacterial communities. A protocol based on mechanical shaking with buffer and enzymes was identified as an optimal approach and used further in this study. The bacterial communities associated with the interstitial water, pea gravel media, and rhizospheric regions from both planted and unplanted CW mesocosms were profiled using the CLPP method and compared. Vertical community stratification was observed for all mesocosm systems. Rhizospheric communities were found to be significantly more active than their gravel-associated counterparts, suggesting that although rhizospheric bacteria were less abundant in the mesocosms they may play a more significant role in the removal and fate of water born contaminants. The start-up dynamics of CW mesocosms was investigated using the CLPP and standard CW characterization methods over an eight month period. All mesocosms showed a steep increase in interstitial community divergence until day 75-100, at which point a steady-state was reached. The interstitial communities were also characterized in terms of similarity based on experimental design treatments (planted/unplanted and origin of seeding inoculum). Four stages were identified during the start-up consisting of an initial stage where mesocosm communities were differentiated based on origin of the inoculum, a period where adjustments and shifts occurred in all mesocosm, a time where all mesocosm communities were quite similar, and a final state where community differentiations were made based plant presence in the mesocosms.

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La description des gradients spatiaux ainsi que la documentation des dynamiques temporelles de la biodiversité sont des piliers centraux de l'écologie moderne, en particulier dans le contexte actuel des changements globaux auquel l'intérêt porté est croissant depuis les dernières décennies. Les communautés écologiques sont désormais reconnues comme des entités issues de la sélection d'espèces à partir d'un pool régional, sélection déterminée par différents processus appelés règles d'assemblage. Les deux règles d'assemblage principalement reconnues sont les filtres environnementaux, sélectionnant des espèces similaires adaptées à un milieu, et la limite à la ressemblance, sélectionnant des espèces dont les caractéristiques n'induisent pas de compétition trop forte et permettent la coexistence. Les objectifs de ma thèse ont été de (i) comprendre les patrons spatiaux de la diversité des communautés piscicoles à large échelle, (ii) comprendre la dynamique temporelle de cette diversité et (iii) d'appréhender la dynamique temporelle des processus sous-jacents à la structuration des communautés. Pour ce faire, des données de communautés piscicoles ont été analysées, d'une part à l'échelle continentale (i.e. européenne), et d'autre part à l'échelle nationale (i.e. France) pour laquelle la dimension temporelle est également disponible (i.e. séries temporelles depuis 1966 jusqu'à 2012). La description de la diversité piscicole européenne a permis de mettre en évidence la complémentarité des facettes phylogénétique, morphologique et écologique de la diversité. De plus, le climat, et en particulier la saisonnalité des conditions climatiques, est apparu comme un déterminant majeur de la distribution spatiale de la diversité. A une échelle plus locale et en tenant compte de la temporalité des communautés, il a été mis en évidence que les communautés piscicoles françaises connaissaient actuellement une réorganisation taxonomique due aux déclins de populations et menant à une homogénéisation taxonomique globale. Bien qu'une réorganisation fonctionnelle de ces mêmes communautés ait été observée, résultant des variations démographiques des espèces d'eau chaude et de bas niveau trophique, les conséquences à large échelle restent à explorer. De plus, depuis les années 90, les filtres environnementaux se sont renforcés dans leur rôle structurant des communautés. Finalement, les travaux de cette thèse ont permis de valider des hypothèses usuellement associées aux patrons spatiaux de la diversité, comme mécanismes en lien avec les variations temporelles de la diversité. L'hypothèse de prédominance du stress (au travers des changements de saisonnalités des températures) et de préadaptation des espèces non-natives ont notamment permis de comprendre les dynamiques temporelles de diversité ainsi que des règles d'assemblage sous-jacentes à la structuration des communautés. / The description of spatial patterns as well as temporal dynamics of diversity has been a major cornerstone in modern ecology, especially in the contemporary context of global changes for which a growing concern is notable during last decades. Ecological communities are now acknowledged as the result of species that are sorted by selection from the regional pool. This selection of species is determined by several processes, namely the assembly rules. The two main assembly rules are the habitat filtering, selecting species that are able to inhabit in a given set of abiotic conditions, and the limiting similarity, selecting species for which ecological features are dissimilar in order to avoid a too strong competition and to coexist. The goals of my thesis were to (i) understand spatial patterns of freshwater fish community diversity at large scale, (ii) understand temporal dynamic of this diversity and (iii) describe temporal dynamics of the processes underlying the structuration of communities. In order to do this, data of freshwater fish communities has been analyzed first at continental scale (i.e. European) and then at national scale (i.e. France) for which temporal dimension of the data was also available (time series from 1966 to 2012). Based on the European freshwater diversity, we highlighted that phylogenetic, morphological and ecological facets were complementary. Moreover, climatic conditions, and especially their seasonality, seem to be a major driver of the spatial distribution of diversity. At finer scale and by taking into account the temporality of communities, we found that French freshwater communities experienced taxonomic reorganization due to population declines that ultimately leads to taxonomic homogenization of freshwater diversity in France. Although functional homogenization has been observed due to demographic fluctuations of warm water-dweller and low trophic level species, consequences at large scale remained to be explored. Moreover, since the 90s, habitat filtering increased as structuring force for freshwater fish communities. Finally, this thesis allowed us to validate hypothesis usually associated to spatial patterns of diversity, as mechanisms related to temporal variations of diversity. The stress dominance hypothesis (through temporal trends in temperature seasonality) and preadaption hypothesis (related to non-native species) have been used to understand temporal dynamics of diversity as well as of the assembly rules underlying structuration of communities.

The savanna woodlands of Southern Africa, colloquially termed the miombo, are poorly described in terms of biodiversity compared to other biomes. They have therefore been underrepresented in the wider understanding of how land use intensification is shaping global biodiversity. Land use change is known to reduce biodiversity and disrupt intactness of ecological communities with consequences for ecosystem functioning, resilience, and services. Miombo woodlands are described as biodiversity hotspots due to a high endemism of species and the presence of megafauna. At the same time, they are also considered dynamic socio-ecological systems shaped by disturbances and the land use activities of people. The patterns of biodiversity change in these tropical ecosystems may, therefore, have their own unique contexts, understanding of which will be essential for biodiversity and land use management in these ecosystems. In this thesis, I identified the patterns of biodiversity change in response to the two major land use practices in the two dominant woodland types in southern African woodlands: the selective logging due to charcoal production in the mopane woodlands, and agricultural expansion in the miombo. I also examined the impact of two main disturbance agents, humans and elephants, on habitat structure and biodiversity in mopane woodlands. Across all chapters in this thesis, I investigated the effects of land use change and habitat modification on biodiversity empirically using chronosequences. To understand biodiversity change, I employed a hierarchical multilevel modelling approach making inferences at the three levels of ecological communities: species, community, and meta-community (set of ecological communities at different sites). I selected six villages in the charcoal production hotspot of southern Mozambique and carried out field surveys for three taxonomic groups: trees, mammals and ground beetles. I modelled the counts of trees and beetles and incidence of mammals using meta-community occurrence models in a Bayesian framework with the intensity class of the villages, above-ground biomass and land cover type as predictors. The results suggested that the species richness of trees and mammals declined by 12 and 8.5 % respectively while that of beetles increased by 3.5%, albeit non-significantly. In addition, the beta diversity of trees decreased while that of mammals increased. The results show that while both trees and mammals reduced in richness, they responded differently to charcoal production in terms of community organisation. The trees underwent subtractive homogenisation (decrease in alpha and beta diversities) primarily because of deterministic processes induced by selective harvesting of tree stems for charcoal. Mammal communities, on the other hand, showed subtractive heterogenization (decrease in alpha, but increase in beta diversity) mainly due to random extinctions. In the agriculture frontier of miombo-dominated northern Mozambique, I investigated the effects of fragmentation and habitat loss caused by agricultural expansion on diversity and composition of trees and mammals. I modelled the occurrences of trees and mammals using occupancy models with the fragmentation and quantity of woodland cover as predictors. The model showed that most tree species (n=10), mainly the timber and firewood species, linearly declined in population size as fragmentation increased. Mammals, on the other hand, showed a nonlinear response. Seven mammal species increased at the lower levels of fragmentation. However, at the higher levels, none of the mammal species increased while two declined. Similarly, the species richness of trees linearly declined, while that of mammals increased up to a fragmentation level of 55-65% and declined above this limit. The beta diversity of trees increased with fragmentation while that of mammals decreased. The results suggest that, although fragmentation reduces species richness of both trees and mammals, it affects their species compositions in different ways. Trees undergo subtractive heterogenization due to random species losses while mammals experience subtractive homogenisation mainly due to the combined effects of fragmentation-led habitat loss and intensified hunting. Finally, this study concludes that, above 75% fragmentation or below 26% habitat quantity, both taxonomic groups endure biodiversity loss. The threshold results here corroborate similar habitat quantity thresholds (20-30%) observed elsewhere in different ecosystems. However, they differ with the widespread notion that above 30% habitat quantity, the effect of fragmentation is non-existent. The results here emphasize that taxonomic groups respond differently, the diversity and population size of mammals reduced only after the habitat threshold, whereas, those of trees showed linear decrease with fragmentation most likely due to fragmentation-led habitat loss. Lastly, I examined the effects of disturbance by humans and elephants on habitat structure and bird diversity by conducting a space for time substitution comparison in the mopane woodlands of Zambia. To examine the woodland structure, I modelled the structural attributes of habitat (stem diameter, stand density, and basal area) using mixed models with the proportion of affected stems by humans and elephants as explanatory variables. I found that elephant disturbance was associated with higher stem diameters, low stand densities, but no change in basal area. Human disturbance, on the other hand, was related to reductions in stand density and basal area, but no change in the stem diameter. Further, I tested species and functional diversity of birds against the covariates of habitat structure and disturbance. I found that bird communities reduced in species richness in both, human as well as elephant disturbed areas. However, the functional diversity did not change with elephant disturbance. I concluded that human disturbance reduces woody biomass (basal area is correlated with woody biomass) of mopane woodlands and functional diversity of birds whilst elephants do not. In this thesis, I conclude that human driven land use change in the miombo woodlands erodes alpha diversity of all taxonomic groups. However, increases in beta diversity of mammals with charcoal land use and trees in agricultural land use may maintain their diversities at the meta-community level.

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No. of bitstreams: 2 Tese - Priscila Lemes de Azevedo Silva - 2014.pdf: 8738399 bytes, checksum: ebb4f9ec58380c199dc16142d8009cac (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-03-18 / Global processes such as: habitat loss, overexploitation, invasive species and climate change are driving many species to extinction. In the face of these threats, the development of systematic planning which indicates the most important biodiversity conservation areas has become widely accepted. The establishment of protected areas is the main strategy for the protection of biodiversity and maintenance of ecosystem processes due to its feasibility and economic cost. However, species distribution can be altered by global climate change and, possibly, the current network of protected areas may not be sufficient for species representation in future scenarios. The impact of climate change on biodiversity can be anticipated by spatial prioritization for conservation through the development of dynamic conservation plans. However, it is clear that some species have a more important ecological role than others (due to their biological and life history characteristics) which includes the unique challenge of taking an integrated view of biodiversity in conservation planning into account. The Atlantic Forest is a lush biome which holds 7.7% of the world's known species of amphibians and high concentration of endemic species. However, the Atlantic Forest is also one of the most threatened tropical biomes of the world, mainly due to the loss and fragmentation of natural habitats. This thesis provides proposals for conservation efforts, considering the possible effects of climate change and also the wider aspects of biodiversity. For this, I used the available amphibian data from the Red List of Threatened Species of the International Union for Conservation of Nature, available climate models, information on protected areas by the World Database on Protected Areas, and attributes of species and the phylogenetic tree consistent with specific literature. Chapter 1 highlights a discussion on the impact of climate change and priorities for biodiversity conservation and the importance of including the functional and phylogenetic diversity in conservation efforts. Chapter 2 brings a discussion about available data for conservation studies, as well as the advantages and disadvantages of using maps of extent of occurrence in systematic planning for conservation. Chapter 3 shows the effectiveness of protected areas in maintaining species richness under climate change from consensual projections of species distribution models for amphibians inhabiting of the Atlantic Forest. In this chapter, we identified that protected areas may gain or lose species due to climate change according to the location of the current network of protected areas. Chapter 4 presents an alternative approach to complement the existence of protected areas and incorporates possible changes in species distribution. The prioritization is based mainly on the distribution of species in both present and future scenarios. This chapter outlines a conservation plan that minimizes the effects of climate change on species dispersion. Besides these effects on species dispersion, this solution also minimizes the uncertainty associated with distribution models and prioritizing areas of low uncertainty. Chapter 5 explains the spatial prioritization of conservation, including different aspects of biodiversity, such as: phylogenetic & functional diversity measures and their influence on evolutionary history and underlying ecological processes. The main objective is to identify and compare the places that contain the most information on the taxonomic, phylogenetic and functional diversity, while also indicating the conservation priorities for each biogeographical region of the Atlantic Forest. In conclusion, we present our new and original ideas for conservation and discuss the future prospects and predictions in this area. / Processos globais como a perda de habitat, a superexploração, a invasão de espécies exóticas e as mudanças climáticas estão conduzindo muitas espécies à extinção. Nesse contexto, o desenvolvimento de um planejamento sistemático que indique as áreas mais importantes para a conservação da biodiversidade tem sido amplamente aceito. O estabelecimento de áreas protegidas é a principal estratégia para proteção da biodiversidade e a manutenção dos processos ecossistêmicos devido à viabilidade e ao custo econômico. Todavia, a distribuição das espécies pode ser alterada pelas mudanças climáticas global e, possivelmente, a atual rede de áreas protegidas pode não ser suficiente para representar as espécies no futuro. A priorização espacial para a conservação pode antecipar os impactos das mudanças climáticas sobre a biodiversidade, além de mitigar tais impactos por meio do desenvolvimento de planos dinâmicos de conservação. No entanto, é evidente que algumas espécies têm um papel ecológico mais importante que outras devido às suas características biológicas e à história de vida, portanto, um novo desafio é adotar uma visão integrada da biodiversidade no planejamento da conservação. A Mata Atlântica é um exuberante bioma que detém 7,7% das espécies de anfíbios conhecidas do mundo e grande concentração de espécies endêmicas. Contudo, a Mata Atlântica é também um dos biomas tropicais mais ameaçados do mundo, sobretudo devido à perda e fragmentação dos hábitats naturais. Esta tese fornece propostas para os esforços de conservação, considerando os possíveis efeitos das mudanças climáticas e também os amplos aspectos da biodiversidade. Para tanto, utilizei os dados de anfíbios disponíveis na Lista Vermelha de Espécies Ameaçadas da União Internacional para a Conservação da Natureza para toda a Mata Atlântica,modelos climáticos disponíveis e informações sobre áreas protegidas oferecidas pelo World Database on Protected Areas. Os atributos das espécies e a árvore filogenética estão de acordo coma literatura específica. O capítulo 1 apresenta uma discussão sobre os impactos das mudanças climáticas e as prioridades para a conservação da biodiversidade. Ainda, é discutida a importância de incluir a diversidade funcional e filogenética nos esforços de conservação. O capítulo 2 apresenta os tipos de dados disponíveis para estudos de conservação, além das vantagens e das desvantagens do uso de mapas de extensão de ocorrência no planejamento sistemático para a conservação. O capítulo 3 apresenta a avaliação da eficiência das áreas protegidas em manter a riqueza de espécies no contexto de mudanças climáticas a partir de projeções consensuais dos modelos de distribuição das espécies para anfíbios da Mata Atlântica. Essa avaliação identifica se uma área protegida poderá ganhar ou perder espécies devido às mudanças climáticas considerando a localização da rede atual das áreas protegidas. O capítulo 4 apresenta uma abordagem alternativa para complementar a atual rede de áreas protegidas e incorpora as possíveis mudanças na distribuição das espécies. A priorização baseia-se, principalmente, na distribuição das espécies tanto no presente quanto no futuro e busca minimizar os efeitos dessa mudança na distribuição das espécies a partir de uma medida de dispersão no contexto de mudanças climáticas. Além da medida de dispersão, a solução também minimiza a incerteza associada aos modelos de distribuição, priorizando locais de baixa incerteza. O capítulo 5 apresenta a priorização espacial da conservação, incluindo diferentes aspectos da biodiversidade tal como a diversidade filogenética e funcional cujas medidas inferem tanto a história evolutiva quanto os processos ecológicos subjacentes. O principal objetivo é identificar e comparar os locais que conservam a maior informação sobre a diversidade taxonômica, filogenética e funcional quanto possível. Além disso, são indicadas as prioridades para a conservação para cada região biogeográfica da Mata Atlântica. Finalmente, em sua conclusão, são apresentadas as principais novidades da tese e discutidos os rumos para futuros trabalhos.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2018-05-18T11:35:54Z No. of bitstreams: 1 marcelavenellipyles.pdf: 949685 bytes, checksum: 7bf12c1e314a606c615e187c4d2bb940 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-09-03T16:03:30Z (GMT) No. of bitstreams: 1 marcelavenellipyles.pdf: 949685 bytes, checksum: 7bf12c1e314a606c615e187c4d2bb940 (MD5) / Made available in DSpace on 2018-09-03T16:03:30Z (GMT). No. of bitstreams: 1 marcelavenellipyles.pdf: 949685 bytes, checksum: 7bf12c1e314a606c615e187c4d2bb940 (MD5) Previous issue date: 2018-02-21 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A urbanização está transformando rapidamente nosso mundo e ameaçando a manutenção das funções do ecossistema, como biodiversidade e produção primária. Este estudo teve como objetivo compreender como diferentes histórias de uso da terra afetam a composição funcional e a diversidade das florestas urbanas e quão funcionalmente vulneráveis são essas florestas a futuros distúrbios. Utilizamos dados de nove florestas urbanas com diferentes históricos de uso da terra (HUT), agrupadas em três categorias de intensidade com três florestas em cada: desnudamento do solo (alta intensidade de HUT), cultivo (intensidade média de HUT) e sem histórico de uso da terra (baixa intensidade de HUT) e de três florestas maduras não urbanas (controle), para fins de comparação, todas situadas na Floresta Atlântica Brasileira. Abordamos duas questões: (i) em que medida as florestas urbanas com diferentes históricos de uso da terra diferem na composição e diversidade funcional e (ii) qual é a consequência do histórico de uso da terra na resistência e resiliência funcional das florestas urbanas? A primeira pergunta foi respondida através da categorização de espécies em grupos funcionais e pelos índices de riqueza funcional e dispersão; e a segunda através de uma análise de resistência, baseada em redundância funcional, e uma análise de resiliência, baseada na diversidade de resposta de espécies. Como prevemos, as florestas urbanas mostraram alterações na composição funcional, independente do histórico de uso. No entanto, efeitos negativos sobre a quantidade e diversidade funcional foram apenas encontrados em florestas com uso prévio da terra mais intenso (desnudamento do solo e cultivo). Apenas as florestas urbanas com histórico de uso da terra tiveram reduções significativas na redundância funcional e na diversidade de respostas das espécies. Surpreendentemente, as florestas urbanas sem histórico de uso da terra são capazes de manter altos níveis de diversidade e segurança funcional, semelhantes aos encontrados nas florestas não urbanas. Concluímos que, embora as florestas urbanas ainda possam servir como reservatórios de diversidade funcional e apresentar alguma segurança no fornecimento de suas funções diante de futuros distúrbios, a intensidade o uso prévio da terra é determinante para a redução, homogeneização e vulnerabilidade funcional dessas florestas. / Urbanisation is rapidly transforming our world and threatening the maintenance of ecosystem functions as biodiversity and primary production. This study aimed to understand how different land-use histories affect functional composition and diversity of urban forests and how functionally vulnerable are these forests to future disturbances. We used data from nine urban forests with different land-use histories (LUH) grouped in three intensity categories with three forests in each: soil denudation (high intensity LUH), cropland (medium intensity LUH) and without land use history (low intensity LUH) and from three non-urban mature forests (control), for comparison purposes, all situated in the Brazilian Atlantic forest. We addressed two questions: (i) to what extent do urban forests with different land-use histories differ in functional composition and diversity metrics?; and (ii) how functionally vulnerable are these forests to future disturbances? The first was answered from the species categorization into functional groups and by the functional richness and dispersion indices; and the second through a resistance analysis based on functional redundancy and a resilience analysis based on species response diversity. As we predict, urban forests showed differences in functional composition, regardless of the land use history. However, negative effects on the amount and diversity of functions were only related to the more intense previous land use (cropland and denudation LUH). Only urban forests with some land use history had significant reductions in functional redundancy and species response diversity. Surprisingly, urban forests without land use history are able to maintain high levels of functional diversity and safety, similar to those found in nonurban forests. We conclude that, although urban forests can still serve as reservoirs of functional diversity and may present some safety in the provision of their functions in the face of future disturbances, the intensity of land use history is determinant for the functional reduction, homogenization and vulnerability of these urban forests.