首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 359 毫秒
1.
This study identifies 'centers of endemism' for typhlocybine leafhoppers in China, revealing diversity patterns and congruence of patterns between total species rich- ness and endemism. Distribution patterns of 774 Typhlocybinae (607 described and 167 undescribed species) were mapped on a 1.5° × 1.5° latitude/longitude grid. Total species richness, endemic species richness and weighted endemism richness were calculated for each grid cell. Grid cells within the top 5% highest values of weighted endemism richness were considered as 'centers of endemism'. Diversity patterns by latitude and altitude were obtained through calculating the gradient richness. A congruence of diversity patterns between total species richness and endemism was confirmed using correlation analysis. To investigate the bioclimatic factors (19 variables) contributing to the congruence be- tween total species richness and endemism, we compared the factor's difference between non-endemic and endemic species using the Kruskal-Wallis test. Eleven centers of en- demism, roughly delineated by mountain ranges, were identified in central and southern China, including the south Yunnan, Hengduan Mountains, Qinling Mountains, Hainan Is- land, Taiwan Island and six mountain areas located in western Sichuan, northwest Fujian, southeast Guizhou, southeast Hunan, central and western Guangdong, and north Zhejiang. Total species richness and endemic species richness decreased with increased latitude and had a consistent unimodal response to altitude. The proportions of endemism decreased with increased latitude and increased with rising altitude. Diversity patterns between total species richness and endemism were highly consistent, and 'Precipitation of Coldest Pe- riod' and 'Temperature of Coldest Period' may contribute to the congruence of pattern. Migration ability may play a role in the relationship of endemism and species richness; climate, environment factors and important geologic isolation events can also play crucial effect  相似文献   

2.
Aim This study aimed to identify the ‘centres of endemism’ of the Chinese spermatophyte flora in order to indirectly detect the locations of past glacial refugia. The role of these areas as places for plant survival (‘plant museums’) and/or areas for plant evolution and speciation (‘plant cradles’) was also assessed. Location China. Methods Distribution patterns of 555 plant endemic taxa, taken as a representative sample of the Chinese endemic flora, were mapped on a 1° × 1° latitude/longitude grid. For each grid cell, species richness (total count of species) and weighted richness (down‐weighting each species by the inverse of its range) were calculated. Grid cells within the top 5% of highest values of weighted richness were considered centres of endemism. Based on available information, all plant taxa included in this study were classified into palaeoendemics and neoendemics, and their distributional patterns were represented separately. Results Twenty areas of endemism were identified in central and southern China, roughly corresponding to mountain ranges, including the Hengduan and Daxue Mountains, the Yungui Plateau, central China Mountains, the Nanling Mountains, eastern China Mountains, and Hainan and Taiwan. Although almost all centres of endemism contained both palaeoendemic and neoendemic taxa, considerable differences in their respective numbers were recorded, with the majority of neoendemics on the eastern fringe of the Tibetan Plateau (Hengduan Mountains sensu lato) but more palaeoendemics towards the east. Main conclusions Owing to their varied topography, the mountainous regions of central and southern China have provided long‐term stable habitats, which allowed palaeoendemics to persist and facilitated the process of speciation. Contrasting patterns between the palaeoendemics and neoendemics within refugia might be attributable to the geological and tectonic history of specific areas. The eastern fringe of the Tibetan Plateau clearly constitutes the ‘evolutionary front’ of China, probably as a result of the uninterrupted uplift of the plateau since the late Neogene. In contrast, the tectonic stability of central and southern China during the Tertiary may have facilitated the persistence of relict plant lineages.  相似文献   

3.
Abstract.  1. Based on the geographic distribution database of museum specimens and published literature, the diversity and distribution of aphids in the Qinghai–Tibetan Plateau–Himalayas was studied using the GIS method.
2. A total of 646 aphid species/subspecies belonging to 195 genera in Adelgidae, Phylloxeridae, and 16 subfamilies of Aphididae were recorded from this region; among which Aphidinae shared the highest species proportion (343 species, 53.1%), followed by Greenidinae (63, 9.7%), Eriosomatinae (54, 8.3%), and Lachninae (48, 7.4%). A total of 326 species and 20 genera are endemic to this region.
3. The aphid fauna has diverse faunal components and shows affinity with other zoogeographic realms. It is also rich in alpine species.
4. The aphid fauna exhibits an asymmetric distribution pattern with few species found on the high surface of the plateau. Four distribution centres were mapped. These were (i) the associated mountainous areas of the Qinghai–Tibetan Plateau and the western Qinling Mountains and southern Gansu Province, (ii) the Hengduan Mountains Region, (iii) the eastern Himalayas, and (iv) the western Himalayas.
5. The aphid fauna of the region may have multiple origins, and has been influenced by geological and ecological factors, such as glaciers and diversified vegetation. Possible reasons for the species diversity and distribution patterns are discussed. The implications and priorities for conservation based, on these distribution patterns, are also discussed.  相似文献   

4.
Aim In this study we evaluate patterns of endemism for benthic polychaete species along the southeastern Pacific coast of Chile. Our goals were (1) to describe latitudinal gradients of endemism and identify areas of high endemism, (2) to evaluate the effect of biogeographical limits on endemism patterns, and (3) to evaluate indirectly the role played by evolutionary dynamics on patterns of endemism. Location South‐eastern Pacific coast of Chile, ranging from Arica (18° S) to Cape Horn (56° S). Methods We used a list of 178 species of endemic, shallow benthic polychaetes to evaluate patterns of endemism. Parsimony analysis of endemicity (PAE) and the endemism index (EI) were used to evaluate hierarchical relationships of endemism between different latitudinal bands, and to identify areas with high degrees of endemism and differences in endemism. We evaluated the effect of biogeographical limits on endemic polychaete fauna by testing for the existence of geometric constraints (mid‐domain effect). The role of evolutionary dynamics on latitudinal patterns of endemism was evaluated with nestedness analysis (NA) using the temperature index. Results The PAE analysis indicated two large, separate areas of endemism: (1) the northern area between 18° S and 38° S, and (2) the southern area between 39° S and 56° S. The endemism index showed a maximum value (32 species) around 39°–41° S. Species‐richness curves of each 3° band of latitude showed a clear mid‐domain effect (69%), but the two maximum points of species richness at mid‐latitudes (36° S to 38° S and 39° S to 41° S) did not correspond to the mid‐domain peak in species richness, presenting a greater number of species than expected by the mid‐domain effect. The nestedness analysis showed that the number of genera reaches a maximum of 70 at mid‐latitudes (36°–41° S), decreasing towards both the northern and southern areas. The spatial distribution of the entire data set of endemic species showed a nested pattern (T° = 24.5°, P < 0.0001). Main conclusions Our results strongly support the existence of a latitudinal gradient of endemism for benthic polychaete species along the Chilean coast. The shape of this gradient is clearly non‐linear, with a marked peak of endemism occurring at mid‐latitudes (36°–41° S, endemism hotspot), which also corresponds to a peak in species richness. Furthermore, this hotspot is the midpoint separating two distinct areas of endemism to the north and south. We suggest that the observed pattern of endemism for benthic polychaete taxa of the Chilean coast can be explained by a combination of geometric constraints and historical mechanisms, such as the processes that affected the Chilean coast during the Neogene (e.g. ENSO, oxygen minimum zone, glaciations).  相似文献   

5.
Aims  To delimit areas of endemism in the Patagonian steppe using endemicity analysis (EA), which evaluates areas of endemism by means of an endemicity index, and to compare the resulting endemic areas with those proposed for the Patagonian steppe by previous authors.
Location  The Patagonian steppe, a region of South America found approximately below parallel 36° S to the east of the Andes Mountains.
Methods  Distributional data for 159 species of insects collected in the Patagonian steppe, and consisting of 1317 georeferenced samples were used to identify areas of endemism. A data grid of presence and absence (with cells of 1° × 1°) was constructed. Initially, two different types of EA were performed, seeking areas defined by 'four or more' species. A first analysis was performed without taking into consideration those quadrats where no species had been recorded (empty quadrats), which in many cases meant a discontinuous distribution. The second analysis was performed assuming a continuous distribution for each species. A third analysis, assuming continuous distributions, was performed using 'three or more' as the number of species necessary for an area to be identified as an endemic area.
Results  In the first two analyses, EA recognized the same five areas of endemism: western Patagonia, south-western Payunia, northern Suabandean, southern Subandean and Austral Patagonia. The results of the third analysis allowed the identification of three more areas of endemism: northern Payunia, Chubutian and Santacrucian.
Main conclusions  We identified five areas of endemism for the Patagonian steppe, some of which have been defined in previous contributions. These areas are: Western Patagonia, Payunia and Subandean Patagonia (which can be divided into septentrional and meridional), Central Patagonia (Chubutence and Santacrucense) and Austral Patagonia.  相似文献   

6.
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   

7.
Input data, analytical methods and biogeography of Elegia (Restionaceae)   总被引:1,自引:0,他引:1  
Aim The aim of this paper is to determine the optimal methods for delimiting areas of endemism for Elegia L. (Restionaceae), an endemic genus of the Cape Floristic Region. We assess two methods of scoring the data (presence–absence in regular grids, or in irregular eco‐geographical regions) and three methods for locating biogeographical centres or areas of endemism, and evaluate one method for locating biotic elements. Location The Cape Floristic Region (CFR), South Africa. Methods The distribution of all 48 species of Elegia was mapped as presence–absence data on a quarter‐degree grid and on broad habitat units (eco‐geographical areas). Three methods to delimit areas of endemism were applied: parsimony analysis of endemism (PAE), phenetic cluster analysis, and NDM (‘end em ism’). In addition, we used presence–absence clustering (‘Prabclus’) to delimit biotic elements. The performances of these methods in elucidating the geographical patterns in Elegia were compared, for both types of input data, by evaluating their efficacy in maximizing the proportion of endemics and the number of areas of endemism. Results Eco‐geographical areas perform better than quarter‐degree grids. The eco‐geographical areas are potentially more likely to track the distribution of species. The phenetic approach performed best in terms of its ability to delimit areas of endemism in the study area. The species richness and the richness of range‐restricted species are each highest in the south‐western part of the CFR, decreasing to the north and east. The phytogeographical centres identified in the present study are the northern mountains, the southern mountains (inclusive of the Riviersonderend Mountains and the Cape Peninsula), the Langeberg range, the south coast, the Cape flats, and the west coast. Main conclusions This study demonstrates that (1) eco‐geographical areas should be preferred over a grid overlay in the study of biogeographical patterns, (2) phenetic clustering is the most suitable analytical method for finding areas of endemism, and (3) delimiting biotic elements does not contribute to an understanding of the biogeographical pattern in Elegia. The areas of endemism in Elegia are largely similar to those described in other studies, but there are many detailed differences.  相似文献   

8.
The distribution of cacti species that inhabit the Sierra Madre Oriental (SMO) was analysed. Grid-cells were analysed using parsimony analysis of endemicity (PAE) and endemism indices. Areas characterized by their diagnostic species were determined, aiming to propose areas for the conservation of threatened cacti. Distributional data were obtained from 1936 herbarium specimens, electronic information, and from field collections. Eight areas of endemism and three main clades were obtained from the grid-cell analysis. Areas obtained from the endemism indices are very similar to those obtained with the PAE, but differ in the association of grid-cells. PAE showed endemism patterns indicating that southern and central sections of the SMO province are the areas richest in geographically-restricted species. The results obtained with different endemism indices detected more or less the same areas, although the importance level is different. The corrected weighted endemism index can be considered as a reliable measure of endemism because it is unrelated to species richness. A regionalization of the SMO in three subprovinces is suggested, supported by characteristic cacti taxa and the existence of natural barriers.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 373–389.  相似文献   

9.
Aim The genus Kniphofia contains 71 species with an African–Malagasy distribution, including one species from Yemen. The genus has a general Afromontane distribution. Here we explore whether Kniphofia is a floristic indicator of the Afromontane centre of endemism and diversity. The South Africa Centre of diversity and endemism was explored in greater detail to understand biogeographical patterns. Location Africa, Afromontane Region, southern Africa, Madagascar and Yemen. Methods Diversity and endemism for the genus were examined at the continental scale using a chorological approach. Biogeographical patterns and endemism in the South Africa Centre were examined in greater detail using chorology, phenetics, parsimony analysis of endemicity (PAE) and mapping of range‐restricted taxa. Results Six centres of diversity were recovered, five of which are also centres of endemism. Eight subcentres of diversity are proposed, of which only two are considered subcentres of endemism. The South Africa Centre is the most species‐rich region and the largest centre of endemism for Kniphofia. The phenetic analysis of the South Africa Centre at the full degree square scale recovered three biogeographical areas that correspond with the subcentres obtained from the chorological analysis. The PAE (at the full degree square scale) and the mapping of range‐restricted taxa recovered two and six areas of endemism (AOEs), respectively. These latter two approaches produced results of limited value, possibly as a result of inadequate collecting of Kniphofia species. Only two AOEs were identified by PAE and these are embedded within two of the six AOEs recovered by the mapping of range‐restricted taxa. All the above AOEs are within the three subcentres found by chorological and phenetic analysis (at the full degree square scale) for the South Africa Centre. Main conclusions The centres for Kniphofia broadly correspond to the Afromontane regional mountain systems, but with some notable differences. We regard Kniphofia as a floristic indicator of the Afromontane Region sensu lato. In southern Africa, the phenetic approach at the full‐degree scale retrieved areas that correlate well with those obtained by the chorological approach.  相似文献   

10.
Aim  To develop an approach for assessing the spatial scale of centres of endemism among species level data.
Location Australia.
Methods  Endemism is inherently scale dependent. Therefore, the Corrected Weighted Endemism (CWE) index used by Crisp et al. [ J. Biogeogr. (2001)28:183] is extended to account for species samples in local neighbourhoods as a Spatial CWE index. This then allows an analysis of how the degree of endemism of a location (cell) changes with spatial scale. The quality of the Spatial CWE index results are assessed using three spatial randomizations at the species level with and without preserving species richness and distributional patterns. We show that CWE is equivalent to beta diversity and predict that it should show high rates of change around centres of endemism.
Results  Similar patterns to those found by Crisp et al. using a data set of vascular flora from Australia are retrieved, but the extent to which they are scale dependent is more easily identified. For example, the Central Australian centre discounted by Crisp et al. is identified when a three-cell radius neighbourhood is used. However, the level of endemism in this centre is no greater than in the margins of many of the coastal centres of endemism. Most of the identified centres of endemism are better than random at all scales and are increasingly so as the spatial scale increases. As predicted, the highest rate of change in Spatial CWE (beta diversity) is most often between zero- and one-cell radius neighbours in most centres of endemism.
Main conclusions  The explicit incorporation of geographical space in analyses allows for a greater understanding of the scale-dependence of phenomena, in this case endemism and beta diversity.  相似文献   

11.
Aim We present a biogeographical analysis of the areas of endemism and areas of diversification in the Muscidae. This analysis searched for geographical patterns in the Muscidae to reconstruct elements of the evolutionary biogeographical history of this insect family. Location Andean and Neotropical regions. Method We constructed a geographic database of 728 species from the literature and museum specimens. Areas of endemism were established by parsimony analysis of endemicity (PAE) based on grids of two different sizes: 5° (550 × 550 km) and 2° (220 × 220 km). Areas of diversification were delimited by track analysis that also included phylogenetic information. This process was independently applied to 11 genera. For each genus, we plotted generalized tracks generated by sister species on a map. When these generalized tracks supported inter‐generic nodes they were manually contoured and inferred to be areas of diversification for the Muscidae. Results Thirteen endemic areas were found using the 5° grid, and eight endemic areas resulted from the 2° grid. Ten areas were in agreement with previous studies, and 11 were new. Amazonian and Atlantic areas of diversification agreed with previous areas for the genus Polietina, and new areas of diversification were found in Panama and in central Chile. Main conclusions Six spatial patterns in the Muscidae were identified: (1) areas of endemism in both Pampa and Puna provinces were established with species whose distributions had not previously been analysed; (2) a new area of endemism was established in extreme southern South America, in Tierra del Fuego; (3) two new areas of diversification, which include Panama and central Chile, were identified; (4) a spatial association was identified between the separation of Chiloe Island from the continent and the diversification in Andean species; (5) a north–south track axis and latitudinal node intervals were identified, interpreted as spatial responses to glaciation or glacial retreat in the Andes; and (6) a spatial coincidence of areas of endemism, of diversification and high species richness in the Muscidae was discovered. The analysis of a complete database and the recognition of areas of diversification are extremely important in elucidating novel biogeographical patterns, which will in turn contribute to a better understanding of the geographical patterns of evolution in the Muscidae.  相似文献   

12.
Nested areas of endemism analysis   总被引:1,自引:0,他引:1  
Aim  To develop and evaluate a nested clade approach to aid in the determination of areas of endemism (AoE) in biogeographical studies.
Methods  We adapted the nested clade analysis (NCA) to studies of areas of endemism. For this purpose we adapted several of the programs currently in use. Two data sets were examined using this approach – one involving Sciobius in southern Africa and the other involving terrestrial mammals in Mexico.
Results  Nested clade analysis as applied to areas of endemism produced results similar to those of previous analyses of Sciobus in southern Africa. An analysis of terrestrial mammals in Mexico supports the designation of some biogeographical provinces as areas of endemism while suggesting that other provinces may comprise composite distributions that should be subdivided.
Main conclusions  The nested clade analysis approach utilized primarily in genetic analysis of phylogeographical patterns in population biology studies can be adapted to understanding AoE in the realm of biogeography. This approach offers a statistical paradigm to evaluate AoE suggested by parsimony analysis of endemicity (PAE) trees.  相似文献   

13.
The recognition of areas of endemism (AEs) is important for conservation biology and biogeographical regionalization. Our objective was to quantitatively identify AEs and distributional congruence patterns of native rodents at the tropical/temperate transition in the central Andes. We analysed 6200 geo‐referenced distributional records of 80 species in north‐western Argentina using NDM/VNDM software. We found 20 AEs defined by 22 endemic species (27% of the total rodent fauna) and 34 patterns of distributional congruence in non‐endemic rodents. Geographical range congruence follows two main patterns running parallel along the Andes. One is related to the humid eastern slopes of the Andes (Argentinean Yungas forest) and the other to the high Andes (Argentinean Puna plateau). Endemism was mainly restricted to the southernmost part of the Yungas forest and adjacent dryer valleys (Monte desert). Species diversity was highest in the northern sector of the Argentinean Yungas forest, where several species reach their southern distributional range. This incongruence among hotspots of diversity and endemism has also been also noted in diversity studies at continental and global scales. Our results provide a starting point for conservation planning in the southernmost Central Andes, which combines the taper of tropical diversity and range‐restricted species endemic to the tropical–temperate transition. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112 , 163–179.  相似文献   

14.
The Espinhaço Range, a mountain chain located in the Brazilian states of Minas Gerais and Bahia, contains one of the richest floras in Brazil, with a high frequency of endemic species. Since 2005 it is designated as UNESCO biosphere reserve and is situated at the joint border of two global hotspots for biodiversity conservation. Endemic species with congruent occurrence patterns were identified in order to establish areas of higher endemism within the Espinhaço Range. Taxonomic reviews were analyzed in order to identify endemic taxa and a dataset was elaborated containing 1765 records from 178 endemic species of vascular plants, representing 17 families and including the geographic coordinates for each record. Two maps were produced showing species richness and collection effort in 15′ quadrats. The congruent occurrences were identified and a third map was provided, delimiting 10 candidate areas of endemism for a “parsimony analysis of endemicity” (PAE). One most parsimonious cladogram is then retrieved, evidencing three major clades corresponding to the northern, central and southern portions of the Espinhaço, in addition to four subclades included into the central clade. We finally identified six major areas of endemism. Furthermore, there is a strong correlation between species richness and collector effort, revealing which areas are in need of further field inventories.  相似文献   

15.
The distributions of 51 non-human primate species are used for Parsimony Analysis of Endemicity (PAE) to determine the relationships among 14 interfluvial regions in the Amazon basin, South America. Two most parsimonious cladograms were found. The strict consensus tree of these cladograms suggests an early separation between Lower Amazonia (eastern) and Upper Amazonia (western). The major clusters of interfluvial regions identified in the PAE cladogram are congruent with the areas of endemism delimited for birds. When interfluvial regions are converted into avian areas of endemism, the PAE cladogram is congruent with one of the two general areas cladograms suggested for Amazonia based on phylogenies of several clades of forest birds. Our analysis suggests that PAE can be used as a tool to objectively identify areas of endemism at an intra-continental scale as well as to make historical inferences. However, the value of a PAE cladogram in this latter application should be always evaluated by congruence with area cladograms built upon cladistic biogeography procedures.  相似文献   

16.
We investigate the relative importance of stochastic and environmental/topographic effects on the occurrence of avian centres of endemism, evaluating their potential historical importance for broad‐scale patterns in species richness across Sub‐Saharan Africa. Because species‐rich areas are more likely to be centres of endemism by chance alone, we test two null models: Model 1 calculates expected patterns of endemism using a random draw from the occurrence records of the continental assemblage, whereas Model 2 additionally implements the potential role of geometric constraints. Since Model 1 yields better quantitative predictions we use it to identify centres of endemism controlled for richness. Altitudinal range and low seasonality emerge as core environmental predictors for these areas, which contain unusually high species richness compared to other parts of sub‐Saharan Africa, even when controlled for environmental differences. This result supports the idea that centres of endemism may represent areas of special evolutionary history, probably as centres of diversification.  相似文献   

17.
Abstract. The distribution of plant taxa endemic to the Yucatán Peninsula was studied using Parsimony Analysis of Endemicity (PAE). The known distribution of 162 endemic plant taxa was plotted and the DOMAIN method together with environmental data were used to model the potential distribution for each taxon. The Peninsula was divided into a grid of quarter‐degree cells for the purpose of identifying distribution patterns. A total of 294 cells were analysed using known collection records and potential distribution of endemic taxa data. Two data matrices were constructed, a matrix of known distribution and a matrix of both the known and potential distribution. The two matrices were included in the PAE to identify areas of endemism. The areas determined with the known distribution were restricted and almost half of them remained unresolved, whereas with the potential distribution, approximately 90% of the cells were assigned to any one of the endemicity areas. Four endemism areas were identified: the Yucatán dry zone, Yucatán, El Petén and Belize. The areas of Yucatán and El Petén could be explained by current and Pleistocene climatic conditions and their congruence with other biological groups. Analysis of the potential distribution identified areas with patterns that share current environmental characteristics and a palaeoclimate history. Potential distribution modelling can eliminate uncertainties in biogeographical analysis caused by lack of data distribution and sample variation and produce information about the relationships between areas and taxa as well as the environmental affinities of taxa.  相似文献   

18.
The karst landform in southern China is renowned for its high levels of species diversity and endemism. Globally, karst ecosystems are under threat from unsustainable anthropogenic disturbance and climate changes and are among the most threatened ecosystems worldwide. In this study, we used the typical karst endemic genus in southern China, Primulina Hance, as a model to identify areas within the karst landform with high diversity and to investigate congruence between phylogenetic and species‐based measures of diversity. Using phylogenetic information and species distribution data, we measured geographical patterns of diversity with four metrics: species richness (SR), corrected weighted endemism (CWE), phylogenetic diversity (PD), and phylogenetic endemism (PE). Our results revealed a high spatial congruence among SR, PD, and PE, with hotspot areas identified in the Nanling Mountains (i.e., north Guangdong and northeast Guangxi) and southeast Yungui Plateau (i.e., north and southwest Guangxi), whereas the hotspots of CWE are comparatively uniform throughout the geographic extent. The categorical analysis of neo‐ and paleoendemism identified a pattern of mixed neo‐ and paleoendemism in numerous grid cells, suggesting that karst areas in southern China have acted as both “museums” and “cradles” of plant evolution. Conservation gap analysis of hotspots revealed that the majority of prioritized hotspots (>90%) of the genus are outside of protected areas, therefore indicating the limited effectiveness of national nature reserves for the karst flora. Overall, our results suggest that the karst flora merits more conservation attention and SR can be an effective surrogate to capture PD in conservation planning.  相似文献   

19.
Parsimony Analysis of Endemicity (PAE) has been compared with other methods regarding its performance to identify areas of endemism. It is frequently compared with the Analysis of Endemicity (AE), which seems to perform better than PAE to identify these areas. Here I compare PAE and AE considering the sympatric taxa diagnosed as endemic, being as strictly close as possible to sympatry, and using previously published data of Sciobius (Coleoptera: Curculionidae). AE identified more candidate areas of endemism than PAE, but the number of highly restricted endemic taxa to these areas was insufficient to support them as areas of endemism. Considering strictly sympatry (homopatry), PAE performed better than AE; however, both methods may identify areas with some grade of sympatry, but the recognition of which areas constitute real areas of endemism in the strict sense depends on the interpretation of the researcher.  相似文献   

20.
There is an increasing need for protected areas to conserve biodiversity efficiently. The Anura of sub-equatorial Africa have received little attention, but we quantitatively analyse a database containing presence-only data for anurans of sub-equatorial Africa to determine patterns of distribution and species richness, and discuss the roles of present and past environmental conditions in shaping these patterns. We consider the distribution of areas rich in endemic, range-restricted and Red Data Book (RDB) species to identify areas of significance to conservation. The Eastern Highlands of Zimbabwe and adjacent area in Mozambique, southeastern Malawi and the northern coast of KwaZulu/Natal are particularly species rich, whereas the southwestern Cape of South Africa and northwestern Zambia exhibit high degrees of endemism. Four major biogeographical sub-regions are identified, which can be further subdivided into provinces. All statistically significant, current environmental factors together account for 52.6% of species richness. Annual maximum rainfall, soil type variation, minimum temperature and range of elevation were all positively correlated with species richness. Thus, both habitat influences and history appear to have influenced patterns of anuran richness in the region. Generally, areas of high species richness coincide with those high in range-restricted, endemic and RDB species. In South Africa, the northeastern coast and southwestern Cape are hypothesised to have been both refugia and centres of speciation. Results suggest that the current reserve system in sub-equatorial Africa is inadequate for the conservation of the full complement of anuran species in the region.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号