Global biodiversity protection requires the development of protected areas that include representative samples of different ecosystems and their associated biodiversity (Dudley 1992, Scott et al. 2001a). I compared long-term decline and protection of forests in three major biomes; boreal, temperate and tropical. I found that forests in the temperate biome are less abundant and less protected than forests in the boreal and tropical biomes. I conducted regional analyses for five continents on the degree of protection of temperate forests across naturally occurring geographic and elevational ranges. My results indicate that protected temperate forests do not represent the full geographic and elevational range of naturally occurring temperate forests. Bias in location, elevation and slope of protected areas are present at both the regional and global scale. Better protection of temperate forests is needed if the diversity and resources associated with these forests types across their geographic range is to be preserved.

This research seeks to advance our understanding of how to make better informed species conservation decisions on a global scale and advance our understanding of how species' spatial distributions (their geographic ranges) may be respond to climate change, so we can know which areas should be set aside to ensure their present and future conservation. To understand how species' geographic ranges may change, it's important to first assess how geographic ranges are defined and measured. The quantifiable measurement of a species' geographic range, (its geographic range size), is a key criterion the International Union for the Conservation of Nature uses to determine the conservation status and prioritization of species worldwide. Thus, part one of this thesis evaluates different measures for how geographic range size is commonly quantified in the conservation community, to determine whether some range size measures are more reliable than others.Further, to evaluate how species' geographic ranges may respond to climate change, I examine the climatic factors influencing observable longitudinal range size gradients in the North American tree species range maps from E.L. Little's Atlas of North American Trees.

The island of Sri Lanka’s exceptional biodiversity and enigmatic biogeography begs investigation, as the island is key in understanding the evolution of the Asian tropical flora. Since the Jurassic, Sri Lanka has been subjected to remarkable tectonic changes, thus its flora could have been influenced by that of a number of nearby landmasses, as well giving Sri Lanka the potential to have played a wider role in the assemblage of floras elsewhere. Firstly, as Sri Lanka originated as a fragment of the supercontinent Gondwana, part of its flora may contain Gondwanan relict lineages. There is also the potential for immigration from Laurasia after the Deccan Plate collided with it 45-50 Mya. Further, Sri Lanka may harbour floristic elements from nearby land masses such as Africa and Southeast Asia as a result of long distance dispersals, and in situ speciation has the potential to have played an important role in enhancing the endemic Sri Lankan flora. I tested the relative contributions of the above hypotheses for the possible origins of the Sri Lankan flora using three representative families, Begoniaceae, Sapotaceae and Zingiberaceae. These families represent both herbaceous and woody elements, and have high diversity across the tropics. Dated molecular phylogenies were constructed for each family. I used recent analytical developments in geographic range evolution modelling and ancestral area reconstruction, incorporating a parameter J to test for founder event speciation. A fine scale area coding was used in order to obtain a better picture of the biogeography of continental Asia. Amongst all the models compared, a dispersal-extinction cladogenesis model incorporating founder event speciation proved to be the best fit for the data for all three families. The dates of origin for Sri Lankan lineages considerably post-date the Gondwanan break up, instead suggesting a geologically more recent entry followed by diversification of endemics within the island. The majority of Sri Lankan lineages have an origin in the Sunda Shelf (53%). Persistence of warm temperate and perhumid climate conditions in southwestern Sri Lanka resembling those of Peninsular Malaysia and Sumatra could have facilitated suitable habitats for these massive dispersals from the Sunda Shelf region. Some trans-oceanic long distance dispersals from Africa (11%) are also evidenced, again these are too young to accept a hypothesis of dispersal during the Deccan Plate’s migration close to the African coast during the late Cretaceous, but occurred later during the Miocene. Further, some lineages of Laurasian origin (20%) are evidenced in the Zingiberaceae with ancestral areas of China and Indochina, which is congruent with a post collision invasion. Among the families tested, dispersals have occurred stochastically, one during the Eocene, six during the Oligocene, seven during the Miocene, two during the Pliocene and one during the Pleistocene. The highest number of dispersals occurred during the Miocene when a warm climate was prevailing during the Miocene thermal maximum. My results confirm that in situ speciation is an important contributor to the Sri Lankan flora. More rapid radiation of endemics has occurred during Pliocene-Pleistocene; two endemics in Begoniaceae, ten endemics in Sapotaceae and ten endemics in Zingiberaceae have evolved in situ during this period. Sri Lanka will have been subjected to expansion and contraction of climatic and vegetation zones within the island during glacial and interglacial periods, potentially resulting in allopatric speciation. As a conclusion, long distance dispersals have played a prominent role in the evolution of the Sri Lankan flora. The young ages challenge the vicariant paradigm for the origin and current disjunct distributions of the world’s tropical lineages and provide strong evidence for a youthful tropics at the species level. The thesis contains six chapters; first two are introductory chapters, then there are three analytical chapters, one for each family, and finally a summary chapter is provided. Each analytical chapter is written as a stand-alone scientific publication, thus there is some repetition of relevant content in each.

Made available in DSpace on 2014-07-29T12:05:40Z (GMT). No. of bitstreams: 1 Tese_FINALJoao_Nabout.pdf: 1455749 bytes, checksum: 9b7b11f9fe664d7c2e865eff445ff3d0 (MD5) Previous issue date: 2009-11-17 / Macroecology of the genus Uca (Crustacea, Decapoda): Patterns of diversity, distribution and responses to global change. The genus Uca, composed by 97 species, has a worldwide distribution on coastal marine regions, mainly in tropical environments. Many researches have used the genus Uca as a model of study, although the actual scientific knowledge about this group is dispersed. Moreover, few studies have investigated its global and evolutive patterns. In this sense, considering that the genus Uca has no taxonomic problems (there is a consensus about its distribution and species identification), presents wide geographical distribution and has phylogenetic topologies, this group can be used as an excellent model to test macroecological and evolutionary hypotheses, and to discuss the effects of climate change on coastal organisms. The aim of this study was to detect trends and biases in scientific literature about the genus Uca, as well as to assess macroecological patterns (at a global scale) and to evaluate the influence of climate change on the geographical range size and species richness. Moreover, we associated the information generated to improve conservation strategies for species of the genus Uca. Considering our goals, we generated four papers in this thesis. Among the most prominent results, we observed that, the number of papers about the genus Uca indexed in Thomson ISI database, did not increase between 1991 and 2007, which may indicate the lack of interest of the scientific community on this taxonomic group. Moreover, the majority of the scientific production about the genus Uca came from institutions in the USA. The studies about the genus Uca were mainly characterized as population papers (which analyzes population attributes such as density, distribution and ecological interactions). The results of species accumulation curve demonstrated that the total number of Uca species currently know (97 described species) is substantially lower than the number predicted by the asymptote of the Gompertz model (134 species predicted), suggesting that new species need to be described. However, a new species of Uca is not described since 1987. Models were generated to explain the date of species description based on the body size, geographical range size, human influence and the type of habitat of each species. These models were selected using the Akaike Information Criteria (AIC). The best model among the candidate ones (explaining 37% of the total variance) was composed by variables representing the geographical range size of species, their body size and the human influence on them. In other words, large-bodied species and those widely distributed, mainly in regions with elevated human influence, were described earlier. In another paper of this thesis, we evaluated the levels of phylogenetic heritability of species of the genus Uca on their geographical range size, shape and position. If a strong phylogenetic signal of geographic range sizes exists between close related species, we can predict the unknown geographic range of species through the known geographic range of its relatives, which is useful for conservation purposes. However, the absence of phylogenetic signal was evidenced for this trait. On the other hand, there was a strong phylogenetic pattern considering the position of the range (mainly along longitudinal axis), probably due to mechanisms of vicariant allopatric speciation and to the geographical structure of the cladogenesis of the group. In the last paper, the impact of global changes on geographic range size of genus Uca were modeled, producing a comprehension about a poleward shift and elaborating maps of species richness based in two scenarios of global change. The models generated presented good performance, and predictions are that the species will probably have reduced the geographical range size and some species will be extinct (considering two scenarios until 2050), mainly in the tropical regions. Moreover, the range of species with midpoints in both hemispheres changed towards to poles in the future scenarios of climatic changes. Finally, the results of this set of papers highlighted the urgency of detailed studies for some species of Uca, and in some coastal marine regions (e.g. Indo-West Pacific) to evaluate the actual status of the distribution of species of the genus Uca and the real species richness of this genus. This is essential to generate local strategies aiming to minimize impacts of global change on coastal organism / O gênero Uca é composto atualmente por 97 espécies, distribuídas mundialmente, ocupando ambientes costeiros marinhos, principalmente da região tropical. Diversos campos de pesquisa têm desenvolvidos trabalhos usando o gênero Uca como modelo, entretanto, atualmente o conhecimento científico sobre esse grupo apresenta-se disperso, além disso, estudos sobre padrões globais e evolutivos ainda são incipientes. Dessa forma, considerando que o gênero Uca é taxonomicamente resolvidos (i.e., consenso na distribuição e identificação das espécies), apresenta ampla distribuição geográfica e existem topologias filogenéticas, estes tornam-se excelentes modelos para testar hipóteses macroecólogicas, evolutivas e discutir efeitos de mudanças climáticas sobre organismos costeiros. O objetivo geral desse trabalho foi avaliar tendências e detectar vieses da literatura científica global de caranguejos do gênero Uca, bem como investigar padrões macroecológicos em escala global e a influência das mudanças climáticas na distribuição geográfica e riqueza de espécies desse grupo de caranguejo, além disso, associar as informações geradas para avançar em estratégias de conservação para essas espécies. Dessa forma, considerando o objetivo geral desse trabalho, foram gerados quatro artigos apresentados nessa tese. Dentre os resultados mais importantes, observamos que o número de artigos sobre Uca indexados na base Thomson ISI não aumentou ao longo dos anos (1991 até 2007), o que pode indicar que não houve aumento de interesse da comunidade científica com esse grupo de organismo, além disso, a maior parte da produção científica sobre Uca foi desenvolvidas por instituições dos Estados Unidos. Os estudos sobre Uca foram principalmente caracterizados como artigos de cunho populacional (i.e. analisaram atributos como densidade, distribuição e interações ecológicas). Apesar de um longo tempo não serem descritas novas espécies de Uca (última espécie foi descrita em 1987), os resultados da curva de acumulação de espécies demonstraram que o número total de espécies de Uca atualmente descrito é menor do que o número de espécies predito pela assíntota do modelo de Gompertz (preditos 134 espécies), sugerindo que existem novas espécies de Uca para serem descritas. Além disso, foram gerados modelos para explicar a data de descrição de espécies, baseado no tamanho da carapaça, tamanho da área de distribuição geográfica, influência humana nos locais de ocorrência das espécies e o tipo de habitat da espécie. Esses modelos foram confrontados e selecionados de acordo com o Critério de Informação de Akaike (AIC). O melhor modelo foi composto pelo tamanho da distribuição geográfica, tamanho do corpo e influência humana, explicando 37% da variação total dos dados, dessa forma, as espécies descritas primeiramente apresentaram maior tamanho corpóreo, maiores áreas de distribuição geográfica e ocorrem em regiões de elevada influência humana. Em outro artigo desenvolvido nessa tese, foi avaliado os níveis de herdabilidade filogenética do tamanho, forma e posição da distribuição geográfica de espécies de Uca. A existência do sinal filogenético para o tamanho da distribuição geográfica pode auxiliar em estratégias para conservação, pois é possível prever o tamanho da distribuição geográfica de uma espécie caso se conheça o tamanho da distribuição de uma espécie filogeneticamente próxima. Entretanto, para as espécies de Uca, foi observado ausência de sinal filogenético para esse caráter. Somente a posição da distribuição geográfica (ao longo do eixo longitudinal) apresentou um forte padrão filogenético, possivelmente devido ao processo de especiação alopátrica vicariante e a estrutura geográfica dos clados. Para o último artigo, foram modelados os impactos das mudanças climáticas globais sobre a distribuição geográfica das espécies de Uca, gerando uma compreensão do deslocamento das espécies em direção aos pólos e ainda produzindo um mapa de riqueza de espécies com base em cenário otimistas e pessimistas de mudanças climáticas globais. Os modelos gerados apresentaram bom desempenho, e grande parte das espécies de Uca apresentarão diminuição da distribuição geográfica acarretando perda de espécies (para cenários projetados para 2050), principalmente nas regiões tropicais, ainda assim, as espécies com pontos médios de ocorrência em ambos os hemisfério, tenderão a direcionar-se para os pólos nos cenários futuros de mudanças climáticas. Por fim, os resultados desse conjunto de artigos evidenciam a urgência de estudos ambientais para diversas espécies de Uca e de regiões costeiras (e.g. Indo-Oeste Pacífico) a fim de gerar um painel atualizado da distribuição e riqueza de espécies de Uca, que permitirão gerar estratégias locais para minimizar impactos das mudanças climáticas

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It has been more than two centuries since the latitudinal pattern of increase in taxonomic richness from poles to equator was first documented. After two centuries of research, and with more than two dozen hypotheses proposed, an understanding of the mechanisms underlying this pattern and their relative importance remains incomplete. Factors such as evolutionary history, area and latitude associated variables such as temperature, solar energy, climatic stability and seasonality are known to influence species richness by affecting geographic range size and location over ecological and evolutionary time. Understanding the forces that affect geographic range size is, therefore, integral to our understanding of latitudinal patterns in species richness. Using woody plants as a study system, my dissertation deciphers the latitudinal pattern, if any, in species richness within the evergreen forests of the Western Ghats. These wet evergreen forests form an evolutionarily distinct biogeographic zone, which has remained isolated from its counterparts. This has resulted in a high percentage of endemism among the evergreen woody plants and, therefore, the global geographic ranges of most of these plants are restricted within the boundaries of the Western Ghats. The first main objective of this dissertation is to understand the determinants of geographic range size in the evergreen woody plants of the Western Ghats. Further, the Western Ghats are characterized by a sharp climatic gradient in temperature and rainfall seasonality that is not correlated with mean annual temperature or annual rainfall. This allows a direct test of the hypotheses and predictions that are based on climatic seasonality, without the confounding effect of other climatic correlates of latitude. Therefore, the second main objective of this dissertation is to understand the mechanisms underlying latitudinal patterns in species richness of evergreen woody plants in the Western Ghats. Regional species richness is an outcome of two factors- local species richness of each location within the region and turnover in species composition among the locations, which in turn are a result of patterns in range size, range location and range overlap. To address these two objectives, I first test the effect of climatic niche of a species in determining geographic range size and then examine the effect of latitude associated climatic seasonality on range location and range overlap. Next, I link the observed pattern in range geometry to latitudinal patterns in species turnover and finally to latitudinal patterns in species richness. While the first part of my dissertation study deals with factors that generate spatial variation in species richness, the second part deals with the factors underlying spatial variation in species composition. Environmental heterogeneity and dispersal are considered the most important determinants of species turnover i.e. change in species composition. However, their relative importance in structuring in diverse plant communities within tropical regions across different scales is poorly understood. Hence, the third objective of this dissertation is to understand the processes that influence change in species composition of woody plants within the Western Ghats. Geographic range size and population size are important attributes of species rarity, which are directly linked to their extinction risk. Hence, data on distribution and population status of species can help us focus our efforts on those species that require conservation attention. This is achieved through carrying out species threat assessments based on attributes such as range and population size and then assigning then to a threat category. A majority of species endemic to the Western Ghats have not yet been assessed, largely due to lack of data on their population and distribution status. Therefore, the fourth and the final part of my dissertation explores the application of information on species range size and abundance in prioritizing species for conservation. To address these objectives, I sampled the wet evergreen forests of the Western Ghats along a series of locations distributed across its entire latitudinal gradient. Based on 156 plots, covering a latitudinal gradient of more than 1200 km and comprising of more than 20,000 occurrence locations belonging to more than 450 species of woody plants, I derived quantitative estimates of latitudinal gradients in range size, local and regional richness as well as species turnover. I used a combination of statistical and simulation approaches to discern the mechanisms underlying large-scale pattern in species ranges, richness and turnover. My dissertation is structured as follows.