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Setting aside biodiversity hotspots would be especially compelling if they contained not just enormous numbers of species but also excessive evolutionary history. A recent study seemed to provide evidence for this incentive for hotspot conservation. Sechrest et al . (2002 ) reported that hotspots contain more endemic phylogenetic diversity (PD) than expected based on the numbers of primate and carnivore species they contain. We extend their analysis and revise some of their claims. For primates and threatened carnivores, we show that the original analysis was driven by a single hotspot (Madagascar) that contains an ancient endemic clade. The remaining hotspots harbour less rather than significantly more endemic PD than expected. Thus, while one hotspot contains an enormous excess of evolutionary history, the remaining hotspots do not. Our analysis reveals that the overriding influence of a single hotspot can create the misleading impression that hotspots generally contain excessive evolutionary history. Justification for the hotspot initiative should be based on robust evidence. We join others in endorsing an increased role for detailed phylogenetic analysis in conservation planning.  相似文献   

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Aim To assemble a continental‐scale data set of all available anuran records and investigate trends in endemism and species richness for the Anura. Location Continental Australia. Methods 97,338 records were assembled, covering 75% of the continent. A neighbourhood analysis was applied to recorded locations for each species to measure richness and endemism for each half‐degree grid square (c. 50 km) in the continent. This analysis was performed for all anurans, and also for each of the three main anuran families found in Australia. A Monte Carlo simulation was used to test a null hypothesis that observed centres of endemism could result simply from an unstructured overlapping of species ranges of different sizes. Results Eleven main centres of anuran endemism were identified, the most important being the Wet Tropics and the south‐west near Bunbury‐Augusta and near Walpole. With the exception of south‐western Australia, all of the identified significant endemic centres are in the northern half of the continent. The regions identified as significant for endemism differed from those identified for species richness and are more localized. Species richness is greatest in the Wet Tropics and the Border Ranges. High species richness also occurs in several areas not previously identified along the east and northern coasts. Main conclusions Weighted endemism provides a new approach for determining significant areas for anuran conservation in Australia and areas can be identified that could be targeted for beneficial conservation gains. Patterns in endemism were found to vary markedly between the three main anuran families, and south‐eastern Australia was found to be far less significant than indicated by previous studies. The need for further survey work in inland Australia is highlighted and several priority areas suggested. Our results for species richness remain broadly consistent with trends previously observed for the Australian Anura.  相似文献   

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Orchid diversity provides a unique opportunity to further our understanding of biotic and abiotic factors linked to patterns of richness, endemism, and phylogenetic endemism in many regions. However, orchid diversity is consistently threatened by illegal trade and habitat transformation. Here, we identified areas critical for orchid conservation in the biogeographic province of Megamexico. For this purpose, we evaluated orchid endemism, phylogenetic diversity, and phylogenetic endemism within Megamexico and characterized orchid life forms. Our results indicate that the majority of the regions with the highest estimates of endemism and phylogenetic endemism are in southern Mexico and northern Central America, mostly located on the Pacific side of Megamexico. Among the most important orchid lineages, several belong to epiphytic lineages such as Pleurothallidinae, Laeliinae and Oncidiinae. We also found that species from diverse and distantly related lineages converge in montane forests where suitable substrates for epiphytes abound. Furthermore, the southernmost areas of phylogenetic diversity and endemism of Megamexico are in unprotected areas. Thus, we conclude that the most critical areas for orchid conservation in Megamexico are located in southern Mexico and northern Central America. We recommend that these areas should be given priority by the Mexican system of natural protected areas as complementary conservation areas.  相似文献   

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Mexico is considered an exceptional biogeographic area with a varied endemic flora, however spatial phylogenetic measures of biodiversity have not yet been estimated to understand how its flora assembled to form the current vegetation. Patterns of species richness, endemism, phylogenetic diversity, phylogenetic endemism and centers of neo‐ and paleo‐endemism were determined to examine differences and congruence among these measures, and their implications for conservation. Of 24 360 vascular plant species 10 235 (42%) are endemic. Areas of endemism and phylogenetic endemism were associated with dry forests in zones of topographic complexity in mountain systems, in deserts, and in isolated xeric vegetation. Every single locality where seasonally tropical dry forests have been reported in Mexico was identified as an area of endemism. Significant phylogenetic diversity was the most restricted and occurred in the Trans‐Mexican Volcanic Belt and in the Sierra de Chiapas. Notably, the highest degree of phylogenetic clustering comprising neo‐, paleo‐, and super‐endemism was identified in southernmost Mexico. Most vascular plant lineages diverged in the Miocene (5–20 mya) when arid environments expanded across the world. The location of Mexico between two very large landmasses and the fact that more than fifty percent of its surface is arid favored the establishment of tropical lineages adapted to extreme seasonality and aridity. These lineages were able to migrate from both North and South America across Central America presumably during the Miocene and to diversify, illustrating the signature of the flora of Mexico of areas of endemism with a mixture of neo‐ and paleo‐endemism.  相似文献   

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The phylogenetic diversity of extant lemurs represents one of the most important but least studied aspects of the conservation biology of primates. The phylogenetic diversity of a species is inversely proportional to the relative number and closeness of its phylogenetic relatives. Phylogenetic diversity can then be used to determine conservation priorities for specific biogeographic regions. Although Malagasy strepsirhines represent the highest phylogenetic diversity among primates at the global level, there are few phylogenetic data on species-specific and regional conservation plans for lemurs in Madagascar. Therefore, in this paper the following questions are addressed for extant lemurs: 1) how does the measure of taxonomic uniqueness used by Mittermeier et al. (1992 Lemurs of Madagascar; Gland, Switzerland: IUCN) equate with an index of phylogenetic diversity, 2) what are the regional conservation priorities based on analyses of phylogenetic diversity in extant lemurs, and 3) what conservation recommendations can be made based on analyses of phylogenetic diversity in lemurs? Taxonomic endemicity standardized weight (TESW) indices of phylogenetic diversity were used to determine the evolutionary component of biodiversity and to prioritize regions for conserving lemur taxa. TESW refers to the standardization of phylogenetic diversity indices for widespread taxa and endemicity of species. The phylogenetic data came from recent genetic studies of Malagasy strepsirhines at the species level. Lemur species were assigned as being either present or absent in six biogeographic regions. TESW indices were combined with data on lemur complementarity and protected areas to assign conservation priorities at the regional level. Although there were no overall differences between taxonomic ranks and phylogenetic rankings, there were significant differences for the top-ranked taxa. The phylogenetic component of lemur diversity is greatest for Daubentonia madagascariensis, Allocebus trichotis, Lepilemur septentrionalis, Indri indri, and Mirza coquereli. Regional conservation priorities are highest for lemurs that range into northeast humid forests and western dry forests. Expansion of existing protected areas in these regions may provide the most rapid method for preserving lemurs. In the long term, new protected areas must be created because there are lemur species that: 1) are not found in existing protected areas, 2) exist only in one or two protected areas, and 3) are still being discovered outside the current network of protected areas. Data on the population dynamics and feeding ecology of phylogenetically important species are needed to ensure that protected areas adequately conserve lemur populations in Madagascar.  相似文献   

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A key challenge in ecological research is to integrate data from different scales to evaluate the ecological and evolutionary mechanisms that influence current patterns of biological diversity. We build on recent attempts to incorporate phylogenetic information into traditional diversity analyses and on existing research on beta diversity and phylogenetic community ecology. Phylogenetic beta diversity (phylobetadiversity) measures the phylogenetic distance among communities and as such allows us to connect local processes, such as biotic interactions and environmental filtering, with more regional processes including trait evolution and speciation. When combined with traditional measures of beta diversity, environmental gradient analyses or ecological niche modelling, phylobetadiversity can provide significant and novel insights into the mechanisms underlying current patterns of biological diversity.  相似文献   

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It is often claimed that conserving evolutionary history is more efficient than species‐based approaches for capturing the attributes of biodiversity that benefit people. This claim underpins academic analyses and recommendations about the distribution and prioritization of species and areas for conservation, but evolutionary history is rarely considered in practical conservation activities. One impediment to implementation is that arguments related to the human‐centric benefits of evolutionary history are often vague and the underlying mechanisms poorly explored. Herein we identify the arguments linking the prioritization of evolutionary history with benefits to people, and for each we explicate the purported mechanism, and evaluate its theoretical and empirical support. We find that, even after 25 years of academic research, the strength of evidence linking evolutionary history to human benefits is still fragile. Most – but not all – arguments rely on the assumption that evolutionary history is a useful surrogate for phenotypic diversity. This surrogacy relationship in turn underlies additional arguments, particularly that, by capturing more phenotypic diversity, evolutionary history will preserve greater ecosystem functioning, capture more of the natural variety that humans prefer, and allow the maintenance of future benefits to humans. A surrogate relationship between evolutionary history and phenotypic diversity appears reasonable given theoretical and empirical results, but the strength of this relationship varies greatly. To the extent that evolutionary history captures unmeasured phenotypic diversity, maximizing the representation of evolutionary history should capture variation in species characteristics that are otherwise unknown, supporting some of the existing arguments. However, there is great variation in the strength and availability of evidence for benefits associated with protecting phenotypic diversity. There are many studies finding positive biodiversity–ecosystem functioning relationships, but little work exists on the maintenance of future benefits or the degree to which humans prefer sets of species with high phenotypic diversity or evolutionary history. Although several arguments link the protection of evolutionary history directly with the reduction of extinction rates, and with the production of relatively greater future biodiversity via increased adaptation or diversification, there are few direct tests. Several of these putative benefits have mismatches between the relevant spatial scales for conservation actions and the spatial scales at which benefits to humans are realized. It will be important for future work to fill in some of these gaps through direct tests of the arguments we define here.  相似文献   

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Aim This study aimed to detect distribution patterns and identify diversity hotspots for Chinese endemic woody seed plant species (CEWSPS). Location China. Methods Presence of 6885 CEWSPS throughout China was mapped by taking the Chinese administrative county as the basic spatial analysis unit. The diversity was measured with five indices: endemic richness (ER), weighted endemism (WE), phylogenetic diversity (PD), phylogenetic endemism (PE) and biogeographically weighted evolutionary distinctiveness (BED). Three levels of area (i.e. 1, 5 and 10% of China’s total land area) were used to identify hotspots, but the 5% level was preferred when both the total area of the hotspots identified and the diversity of CEWSPS reached by the hotspots were considered. Results Distribution patterns of CEWSPS calculated with the five indices are consistent with each other over the national extent. However, the hotspots do not show a high degree of consistency among the results derived from the five indices. Those identified with ER and PD are very similar, and so are those with WE and BED. In total, 20 hotspots covering 7.9% of China’s total land area were identified, among which 11 were identified with all the five indices, including the Hengduan Mountains, Xishuangbanna Region, Hainan Island, and eight mountainous areas located in east Chongqing and west Hubei, in east Yunnan and west Guangxi, in north Guangxi, south‐east Guizhou and south‐west Hunan, in north Guangdong and south Hunan, in south‐east Tibet, and in south‐east Hubei and north‐west Jiangxi. Taiwan Island was also identified as a major hotspot with WE, PE and BED. Main conclusions Hotspots of CEWSPS were identified with five indices considering both distributional and phylogenetic information. They cover most of the key areas of biodiversity defined by previous researchers using other approaches. This further verifies the importance of these areas for China’s biodiversity conservation.  相似文献   

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Using complementary metrics to evaluate phylogenetic diversity can facilitate the delimitation of floristic units and conservation priority areas. In this study, we describe the spatial patterns of phylogenetic alpha and beta diversity, phylogenetic endemism, and evolutionary distinctiveness of the hyperdiverse Ecuador Amazon forests and define priority areas for conservation. We established a network of 62 one‐hectare plots in terra firme forests of Ecuadorian Amazon. In these plots, we tagged, collected, and identified every single adult tree with dbh ≥10 cm. These data were combined with a regional community phylogenetic tree to calculate different phylogenetic diversity (PD) metrics in order to create spatial models. We used Loess regression to estimate the spatial variation of taxonomic and phylogenetic beta diversity as well as phylogenetic endemism and evolutionary distinctiveness. We found evidence for the definition of three floristic districts in the Ecuadorian Amazon, supported by both taxonomic and phylogenetic diversity data. Areas with high levels of phylogenetic endemism and evolutionary distinctiveness in Ecuadorian Amazon forests are unprotected. Furthermore, these areas are severely threatened by proposed plans of oil and mining extraction at large scales and should be prioritized in conservation planning for this region.  相似文献   

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Traditional attempts to delineate floristic regions are typically based on the qualitative analysis of species distribution, often ignoring the phylogenetic relationships among their taxa. Ethiopia and Eritrea are in the Horn of Africa, known as one of the world's biodiversity hotspots. We quantitatively classified the flora of Ethiopia and Eritrea into meaningful geographical units by analyzing the taxonomic and phylogenetic β‐diversity at genera, total species, and endemic species levels at a scale of 0.5° × 0.5° grid cells. Hierarchical clustering was used to quantitatively delimitate the flora and analysis of similarities was used to test the significant difference between the derived groups in taxonomic composition and phylogenetic relatedness. In total, two floristic subprovinces, five floristic districts, and 13 floristic subdistricts, as well as three centers of species endemism associated with three floristic subdistricts were identified. Our results also showed that the species diversity, endemism, and turnover of the highlands in Ethiopia and Eritrea were much higher than the lowlands, indicating that the floristic differences are closely related to the topography of the East African Rift. In this study, we provided a scientific framework for the composition and relationships of the floristic units in the Horn of Africa, and similarly provided a scientific basis for better conservation of the diversity in this region.  相似文献   

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Panbiogeography represents an evolutionary approach to biogeography, using rational cost-efficient methods to reduce initial complexity to locality data, and depict general distribution patterns. However, few quantitative, and automated panbiogeographic methods exist. In this study, we propose a new algorithm, within a quantitative, geometrical framework, to perform panbiogeographical analyses as an alternative to more traditional methods. The algorithm first calculates a minimum spanning tree, an individual track for each species in a panbiogeographic context. Then the spatial congruence among segments of the minimum spanning trees is calculated using five congruence parameters, producing a general distribution pattern. In addition, the algorithm removes the ambiguity, and subjectivity often present in a manual panbiogeographic analysis. Results from two empirical examples using 61 species of the genus Bomarea (2340 records), and 1031 genera of both plants and animals (100118 records) distributed across the Northern Andes, demonstrated that a geometrical approach to panbiogeography is a feasible quantitative method to determine general distribution patterns for taxa, reducing complexity, and the time needed for managing large data sets.  相似文献   

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How fast does biodiversity respond to climate change? The relationship of past and current climate with phylogenetic assemblage structure helps us to understand this question. Studies of angiosperm tree diversity in North America have already suggested effects of current water–energy balance and tropical niche conservatism. However, the role of glacial–interglacial climate variability remains to be determined, and little is known about any of these relationships for gymnosperms. Moreover, phylogenetic endemism, the concentration of unique lineages in restricted ranges, may also be related to glacial–interglacial climate variability and needs more attention. We used a refined phylogeny of both angiosperms and gymnosperms to map phylogenetic diversity, clustering and endemism of North American trees in 100‐km grid cells, and climate change velocity since Last Glacial Maximum together with postglacial accessibility to recolonization to quantify glacial–interglacial climate variability. We found: (1) Current climate is the dominant factor explaining the overall patterns, with more clustered angiosperm assemblages toward lower temperature, consistent with tropical niche conservatism. (2) Long‐term climate stability is associated with higher angiosperm endemism, while higher postglacial accessibility is linked to to more phylogenetic clustering and endemism in gymnosperms. (3) Factors linked to glacial–interglacial climate change have stronger effects on gymnosperms than on angiosperms. These results suggest that paleoclimate legacies supplement current climate in shaping phylogenetic patterns in North American trees, and especially so for gymnosperms.  相似文献   

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Nothostele is a rare genus endemic to central Brazil. The taxonomy of the genus is controversial and almost every taxonomist has had a different point of view regarding its generic and subtribal classification. After the first collection 138 years ago, N. acianthiformis has been collected again and we report here a phylogenetic analysis of the genus based on nuclear ribosomal internal transcribed spacer and plastid matK and trnLtrnF sequence data. Our results show that Nothostele belongs to subtribe Spiranthinae and is sister to Eltroplectris within the Stenorrhynchos clade. A reanalysis of gynostemium morphology shows that the presence of a hamulus was misinterpreted in Nothostele and that the placement of the genus in Cranichidinae based on morphology of the pollinarium is unwarranted. Furthermore, the flattened, sessile, prostrate leaves of N. acianthiformis, which are described here for the first time, occur in some Spiranthinae but are atypical in Cranichidinae. Specimens from Brasília in the Brazilian central plateau are a distinct new species, which is described here as N. brasiliaënsis. Currently, the genus comprises two disjunct species restricted to the cerrado and rocky field vegetation of central Brazil. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 165 , 348–363.  相似文献   

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