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Gerald M. Schneeweiss - One of the best experts on this subject based on the ideXlab platform.
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endemic diversity and distribution of the iranian vascular flora across phytogeographical regions biodiversity hotspots and areas of Endemism
Scientific Reports, 2019Co-Authors: Jalil Noroozi, Zahra Asgarpour, Amir Talebi, Moslem Doostmohammadi, Sara Manafzadeh, Gerald M. SchneeweissAbstract:Endemism is one of the most important concepts in biogeography and is of high relevance for conservation biology. Nevertheless, our understanding of patterns of Endemism is still limited in many regions of high biodiversity. This is also the case for Iran, which is rich in biodiversity and Endemism, but there is no up-to-date account of diversity and distribution of its endemic species. In this study, a comprehensive list of all endemic vascular plant species of Iran, their taxonomic composition and their geographical distribution are presented. To this end, a total of 2,597 (sub)endemic vascular plant species of Iran were documented and their distribution in three phytogeographical regions, two biodiversity hotspots and five areas of Endemism were analysed. The Irano-Turanian phytogeographical region harbours 88% of the Iranian endemics, the majority of which are restricted to the Irano-Anatolian biodiversity hotspot (84%). Nearly three quarters of the endemic species are restricted to mountain ranges. The rate of Endemism increases along an elevational gradient, causing the alpine zone to harbour a disproportionally high number of endemics. With increasing pastoralism, urbanization, road construction and ongoing climate change, the risk of biodiversity loss in the Iranian mountains is very high, and these habitats need to be more effectively protected.
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Table_2_Patterns of Endemism in Turkey, the Meeting Point of Three Global Biodiversity Hotspots, Based on Three Diverse Families of Vascular Plants.docx
2019Co-Authors: Jalil Noroozi, Golshan Zare, Mahbubeh Sherafati, Mohammad Mahmoodi, Dietmar Moser, Zahra Asgarpour, Gerald M. SchneeweissAbstract:Centers of Endemism and areas of Endemism are important biogeographic concepts with high relevance for conservation and evolutionary biology. Turkey is located at the intersection of three global biodiversity hotspots (Mediterranean, Caucasian, Irano-Anatolian) and harbors remarkable levels of plant diversity and Endemism. Nevertheless, hotspots of vascular plant endemics have never been identified using formal quantitative approaches in this diverse region. Here, using data on 1,102 endemic taxa of three species-rich families (Asteraceae, Lamiaceae, Boraginaceae) we identified (i) centers of Endemism based on three well-established indices (endemic richness, range-restricted endemic richness and weighted endemic richness) and (ii) areas of Endemism using Endemicity Analysis. A total of 14 grid cells belonging to centers of Endemism are identified as hotspots by at least one of the indices. Areas of Endemism were identified in south-western Turkey (West-Taurus), southern and central Anatolia (Anatolian Diagonal), in north-eastern Turkey (Pontic-Ala), and in south-eastern Turkey (Hakkari). All hotspots of plant Endemism in Turkey included high mountains, which are severely threatened by anthropogenic activities. Although the identified centers of Endemism cover only 16% of surface area of Turkey they harbor 59% of the endemic taxa, emphasizing their conservation priority. As the majority of the endemic taxa of Turkey are local endemics and narrowly distributed, protection of the identified hotspots would allow a high proportion of likely threatened species to be protected.
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Patterns of Endemism in Turkey, the Meeting Point of Three Global Biodiversity Hotspots, Based on Three Diverse Families of Vascular Plants
Frontiers Media S.A., 2019Co-Authors: Jalil Noroozi, Golshan Zare, Mahbubeh Sherafati, Mohammad Mahmoodi, Dietmar Moser, Zahra Asgarpour, Gerald M. SchneeweissAbstract:Centers of Endemism and areas of Endemism are important biogeographic concepts with high relevance for conservation and evolutionary biology. Turkey is located at the intersection of three global biodiversity hotspots (Mediterranean, Caucasian, Irano-Anatolian) and harbors remarkable levels of plant diversity and Endemism. Nevertheless, hotspots of vascular plant endemics have never been identified using formal quantitative approaches in this diverse region. Here, using data on 1,102 endemic taxa of three species-rich families (Asteraceae, Lamiaceae, Boraginaceae) we identified (i) centers of Endemism based on three well-established indices (endemic richness, range-restricted endemic richness and weighted endemic richness) and (ii) areas of Endemism using Endemicity Analysis. A total of 14 grid cells belonging to centers of Endemism are identified as hotspots by at least one of the indices. Areas of Endemism were identified in south-western Turkey (West-Taurus), southern and central Anatolia (Anatolian Diagonal), in north-eastern Turkey (Pontic-Ala), and in south-eastern Turkey (Hakkari). All hotspots of plant Endemism in Turkey included high mountains, which are severely threatened by anthropogenic activities. Although the identified centers of Endemism cover only 16% of surface area of Turkey they harbor 59% of the endemic taxa, emphasizing their conservation priority. As the majority of the endemic taxa of Turkey are local endemics and narrowly distributed, protection of the identified hotspots would allow a high proportion of likely threatened species to be protected
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hotspots within a global biodiversity hotspot areas of Endemism are associated with high mountain ranges
Scientific Reports, 2018Co-Authors: Jalil Noroozi, H P Linder, Amir Talebi, Moslem Doostmohammadi, Sabine B Rumpf, Gerald M. SchneeweissAbstract:Conservation biology aims at identifying areas of rich biodiversity. Currently recognized global biodiversity hotspots are spatially too coarse for conservation management and identification of hotspots at a finer scale is needed. This might be achieved by identification of areas of Endemism. Here, we identify areas of Endemism in Iran, a major component of the Irano-Anatolian biodiversity hotspot, and address their ecological correlates. Using the extremely diverse sunflower family (Asteraceae) as our model system, five consensus areas of Endemism were identified using the approach of endemicity analysis. Both endemic richness and degree of endemicity were positively related to topographic complexity and elevational range. The proportion of endemic taxa at a certain elevation (percent Endemism) was not congruent with the proportion of total surface area at this elevation, but was higher in mountain ranges. While the distribution of endemic richness (i.e., number of endemic taxa) along an elevational gradient was hump-shaped peaking at mid-elevations, the percentage of Endemism gradually increased with elevation. Patterns of endemic richness as well as areas of Endemism identify mountain ranges as main centres of Endemism, which is likely due to high environmental heterogeneity and strong geographic isolation among and within mountain ranges. The herein identified areas can form the basis for defining areas with conservation priority in this global biodiversity hotspot.
Jalil Noroozi - One of the best experts on this subject based on the ideXlab platform.
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endemic diversity and distribution of the iranian vascular flora across phytogeographical regions biodiversity hotspots and areas of Endemism
Scientific Reports, 2019Co-Authors: Jalil Noroozi, Zahra Asgarpour, Amir Talebi, Moslem Doostmohammadi, Sara Manafzadeh, Gerald M. SchneeweissAbstract:Endemism is one of the most important concepts in biogeography and is of high relevance for conservation biology. Nevertheless, our understanding of patterns of Endemism is still limited in many regions of high biodiversity. This is also the case for Iran, which is rich in biodiversity and Endemism, but there is no up-to-date account of diversity and distribution of its endemic species. In this study, a comprehensive list of all endemic vascular plant species of Iran, their taxonomic composition and their geographical distribution are presented. To this end, a total of 2,597 (sub)endemic vascular plant species of Iran were documented and their distribution in three phytogeographical regions, two biodiversity hotspots and five areas of Endemism were analysed. The Irano-Turanian phytogeographical region harbours 88% of the Iranian endemics, the majority of which are restricted to the Irano-Anatolian biodiversity hotspot (84%). Nearly three quarters of the endemic species are restricted to mountain ranges. The rate of Endemism increases along an elevational gradient, causing the alpine zone to harbour a disproportionally high number of endemics. With increasing pastoralism, urbanization, road construction and ongoing climate change, the risk of biodiversity loss in the Iranian mountains is very high, and these habitats need to be more effectively protected.
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Table_2_Patterns of Endemism in Turkey, the Meeting Point of Three Global Biodiversity Hotspots, Based on Three Diverse Families of Vascular Plants.docx
2019Co-Authors: Jalil Noroozi, Golshan Zare, Mahbubeh Sherafati, Mohammad Mahmoodi, Dietmar Moser, Zahra Asgarpour, Gerald M. SchneeweissAbstract:Centers of Endemism and areas of Endemism are important biogeographic concepts with high relevance for conservation and evolutionary biology. Turkey is located at the intersection of three global biodiversity hotspots (Mediterranean, Caucasian, Irano-Anatolian) and harbors remarkable levels of plant diversity and Endemism. Nevertheless, hotspots of vascular plant endemics have never been identified using formal quantitative approaches in this diverse region. Here, using data on 1,102 endemic taxa of three species-rich families (Asteraceae, Lamiaceae, Boraginaceae) we identified (i) centers of Endemism based on three well-established indices (endemic richness, range-restricted endemic richness and weighted endemic richness) and (ii) areas of Endemism using Endemicity Analysis. A total of 14 grid cells belonging to centers of Endemism are identified as hotspots by at least one of the indices. Areas of Endemism were identified in south-western Turkey (West-Taurus), southern and central Anatolia (Anatolian Diagonal), in north-eastern Turkey (Pontic-Ala), and in south-eastern Turkey (Hakkari). All hotspots of plant Endemism in Turkey included high mountains, which are severely threatened by anthropogenic activities. Although the identified centers of Endemism cover only 16% of surface area of Turkey they harbor 59% of the endemic taxa, emphasizing their conservation priority. As the majority of the endemic taxa of Turkey are local endemics and narrowly distributed, protection of the identified hotspots would allow a high proportion of likely threatened species to be protected.
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Patterns of Endemism in Turkey, the Meeting Point of Three Global Biodiversity Hotspots, Based on Three Diverse Families of Vascular Plants
Frontiers Media S.A., 2019Co-Authors: Jalil Noroozi, Golshan Zare, Mahbubeh Sherafati, Mohammad Mahmoodi, Dietmar Moser, Zahra Asgarpour, Gerald M. SchneeweissAbstract:Centers of Endemism and areas of Endemism are important biogeographic concepts with high relevance for conservation and evolutionary biology. Turkey is located at the intersection of three global biodiversity hotspots (Mediterranean, Caucasian, Irano-Anatolian) and harbors remarkable levels of plant diversity and Endemism. Nevertheless, hotspots of vascular plant endemics have never been identified using formal quantitative approaches in this diverse region. Here, using data on 1,102 endemic taxa of three species-rich families (Asteraceae, Lamiaceae, Boraginaceae) we identified (i) centers of Endemism based on three well-established indices (endemic richness, range-restricted endemic richness and weighted endemic richness) and (ii) areas of Endemism using Endemicity Analysis. A total of 14 grid cells belonging to centers of Endemism are identified as hotspots by at least one of the indices. Areas of Endemism were identified in south-western Turkey (West-Taurus), southern and central Anatolia (Anatolian Diagonal), in north-eastern Turkey (Pontic-Ala), and in south-eastern Turkey (Hakkari). All hotspots of plant Endemism in Turkey included high mountains, which are severely threatened by anthropogenic activities. Although the identified centers of Endemism cover only 16% of surface area of Turkey they harbor 59% of the endemic taxa, emphasizing their conservation priority. As the majority of the endemic taxa of Turkey are local endemics and narrowly distributed, protection of the identified hotspots would allow a high proportion of likely threatened species to be protected
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hotspots within a global biodiversity hotspot areas of Endemism are associated with high mountain ranges
Scientific Reports, 2018Co-Authors: Jalil Noroozi, H P Linder, Amir Talebi, Moslem Doostmohammadi, Sabine B Rumpf, Gerald M. SchneeweissAbstract:Conservation biology aims at identifying areas of rich biodiversity. Currently recognized global biodiversity hotspots are spatially too coarse for conservation management and identification of hotspots at a finer scale is needed. This might be achieved by identification of areas of Endemism. Here, we identify areas of Endemism in Iran, a major component of the Irano-Anatolian biodiversity hotspot, and address their ecological correlates. Using the extremely diverse sunflower family (Asteraceae) as our model system, five consensus areas of Endemism were identified using the approach of endemicity analysis. Both endemic richness and degree of endemicity were positively related to topographic complexity and elevational range. The proportion of endemic taxa at a certain elevation (percent Endemism) was not congruent with the proportion of total surface area at this elevation, but was higher in mountain ranges. While the distribution of endemic richness (i.e., number of endemic taxa) along an elevational gradient was hump-shaped peaking at mid-elevations, the percentage of Endemism gradually increased with elevation. Patterns of endemic richness as well as areas of Endemism identify mountain ranges as main centres of Endemism, which is likely due to high environmental heterogeneity and strong geographic isolation among and within mountain ranges. The herein identified areas can form the basis for defining areas with conservation priority in this global biodiversity hotspot.
Shawn W Laffan - One of the best experts on this subject based on the ideXlab platform.
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continental scale spatial phylogenetics of australian angiosperms provides insights into ecology evolution and conservation
Journal of Biogeography, 2016Co-Authors: Nunzio Knerr, Andrew H Thornhill, Brent D Mishler, Carlos E Gonzalezorozco, Craig M Costion, Darren M Crayn, Shawn W LaffanAbstract:Aim Biodiversity studies typically use species, or more recently phylogenetic diversity (PD), as their analysis unit and produce a single map of observed diversity. However, observed biodiversity is not necessarily an indicator of significant biodiversity and therefore should not be used alone. By applying a small number of additional metrics to PD, with associated statistical tests, we can determine whether more or less of the phylogeny occurs in an area, whether branch lengths in an area are longer or shorter, and whether more long or short-branched Endemism occurs in an area, than expected under a null model. Location Australian continent. Methods We used a phylogeny sampling 90% of Australia's angiosperm genera, and 3.4 million georeferenced plant specimens downloaded from Australia's Virtual Herbarium (AVH), to calculate PD, relative phylogenetic diversity (RPD) and relative phylogenetic Endemism (RPE). Categorical analysis of neo- and palaeo-Endemism (CANAPE) and randomization tests were performed to determine statistical significance. Results We identify several combinations of significant PD and Endemism across the continent that are not seen using observed diversity patterns alone. Joint interpretation of these combinations complements the previous interpretations of Australia's plant evolutionary history. Of conservation concern, only 42% of the significant Endemism cells found here overlap with existing nature reserves. Main conclusions These spatial phylogenetic methods are feasible to apply to a whole flora at the continental scale. Observed richness or PD is inadequate to fully understand the patterns of biodiversity. The combination of statistical tests applied here can be used to better explain biodiversity patterns and the evolutionary and ecological processes that have created them. The spatial phylogenetic methods used in this paper can be also be used to identify conservation priorities at any geographical scale or taxonomic level.
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phylogenetic measures of biodiversity and neo and paleo Endemism in australian acacia
Nature Communications, 2014Co-Authors: Nunzio Knerr, Shawn W Laffan, Andrew H Thornhill, Brent D Mishler, Carlos E Gonzalezorozco, Joseph T. MillerAbstract:Understanding spatial patterns of biodiversity is critical for conservation planning, particularly given rapid habitat loss and human-induced climatic change. Diversity and Endemism are typically assessed by comparing species ranges across regions. However, investigation of patterns of species diversity alone misses out on the full richness of patterns that can be inferred using a phylogenetic approach. Here, using Australian Acacia as an example, we show that the application of phylogenetic methods, particularly two new measures, relative phylogenetic diversity and relative phylogenetic Endemism, greatly enhances our knowledge of biodiversity across both space and time. We found that areas of high species richness and species Endemism are not necessarily areas of high phylogenetic diversity or phylogenetic Endemism. We propose a new method called categorical analysis of neo- and paleo-Endemism (CANAPE) that allows, for the first time, a clear, quantitative distinction between centres of neo- and paleo-Endemism, useful to the conservation decision-making process.
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phylogenetic Endemism a new approach for identifying geographical concentrations of evolutionary history
Molecular Ecology, 2009Co-Authors: Dan F. Rosauer, Michael D Crisp, Shawn W Laffan, Stephen C Donnellan, Lynette Gai CookAbstract:We present a new, broadly applicable measure of the spatial restriction of phylogenetic diversity, termed phylogenetic Endemism (PE). PE combines the widely used phylogenetic diversity and weighted Endemism measures to identify areas where substantial components of phylogenetic diversity are restricted. Such areas are likely to be of considerable importance for conservation. PE has a number of desirable properties not combined in previous approaches. It assesses Endemism consistently, independent of taxonomic status or level, and independent of previously defined political or biological regions. The results can be directly compared between areas because they are based on equivalent spatial units. PE builds on previous phylogenetic analyses of Endemism, but provides a more general solution for mapping Endemism of lineages. We illustrate the broad applicability of PE using examples of Australian organisms having contrasting life histories: pea-flowered shrubs of the genus Daviesia (Fabaceae) and the Australian species of the Australo-Papuan tree frog radiation within the family Hylidae.
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assessing Endemism at multiple spatial scales with an example from the australian vascular flora
Journal of Biogeography, 2003Co-Authors: Shawn W Laffan, Michael D CrispAbstract: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.
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Endemism in the australian flora
Journal of Biogeography, 2001Co-Authors: Michael D Crisp, H P Linder, Shawn W Laffan, A MonroAbstract:Aim To detect centres of vascular plant Endemism at a continental scale by analysis of specimen-based distributional data and to relate any pattern to environmental factors and history. Location Australia. Methods Presence of 8468 seed plant species-level taxa throughout continental Australia and Tasmania was mapped on a 1∞ grid to visualize the pattern of species richness. This sample comprises half the known flora. Three indices of Endemism were calculated but we preferred one that is unrelated to species richness, so that these two concepts could be distinguished in practice. Centres of Endemism were detected by simple mapping and by spatial autocorrelation analysis (SAC). Linear regression was used to examine the relationship of the patterns of species richness and Endemism to latitude, topography and climate. Results Both species richness and Endemism vary greatly across the continent but in most cases the same centres were high in both richness and Endemism. Twelve distinct centres were identified. The major centres of both diversity and Endemism are south-west western Australia, the Border Ranges between New South Wales and Queensland, the Wet Tropics near Cairns, Tasmania and the Iron-McIlwraith Range of eastern Cape York Peninsula. The last centre appears to be more significant than recognized by past authors. Whether this is a true Australian centre of Endemism, or is largely an outlier of the flora of Papua New Guinea, is explored. Another centre, in the Adelaide‐Kangaroo Island region, has been overlooked altogether by previous authors. Regression analysis did not find a simple climatic explanation of the observed patterns. There was a suggestion that topographic variation within the 1∞ cells may be positively correlated with Endemism, which is consistent with mountainous regions functioning as refugia. One clear result is that all the major centres of Endemism are near-coastal. A likely explanation is that Pleistocene expansions of the central desert have been a powerful limitation on the viability of refugia for narrowly endemic species. All the centres of Endemism lie outside the estimated limits of the expanded arid zone at the last glacial maximum (18,000 yr BP). In particular, the ‘Central Australian Mountain Ranges centre of plant diversity and Endemism’ of Boden & Given (1995) is detected as a strong centre of species richness, but not at all as a centre of Endemism. This is despite good sampling of this region. Main conclusions Endemism can be distinguished from species richness by using an appropriate index and mapping of such indices can detect centres of Endemism. This study demonstrates the value of specimen based distributional data, such as is held in state herbaria and museums.
H P Linder - One of the best experts on this subject based on the ideXlab platform.
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hotspots within a global biodiversity hotspot areas of Endemism are associated with high mountain ranges
Scientific Reports, 2018Co-Authors: Jalil Noroozi, H P Linder, Amir Talebi, Moslem Doostmohammadi, Sabine B Rumpf, Gerald M. SchneeweissAbstract:Conservation biology aims at identifying areas of rich biodiversity. Currently recognized global biodiversity hotspots are spatially too coarse for conservation management and identification of hotspots at a finer scale is needed. This might be achieved by identification of areas of Endemism. Here, we identify areas of Endemism in Iran, a major component of the Irano-Anatolian biodiversity hotspot, and address their ecological correlates. Using the extremely diverse sunflower family (Asteraceae) as our model system, five consensus areas of Endemism were identified using the approach of endemicity analysis. Both endemic richness and degree of endemicity were positively related to topographic complexity and elevational range. The proportion of endemic taxa at a certain elevation (percent Endemism) was not congruent with the proportion of total surface area at this elevation, but was higher in mountain ranges. While the distribution of endemic richness (i.e., number of endemic taxa) along an elevational gradient was hump-shaped peaking at mid-elevations, the percentage of Endemism gradually increased with elevation. Patterns of endemic richness as well as areas of Endemism identify mountain ranges as main centres of Endemism, which is likely due to high environmental heterogeneity and strong geographic isolation among and within mountain ranges. The herein identified areas can form the basis for defining areas with conservation priority in this global biodiversity hotspot.
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on areas of Endemism with an example from the african restionaceae
Systematic Biology, 2001Co-Authors: H P LinderAbstract:Areas of Endemism are central to cladistic biogeography. The concept has been much de- bated in the past, and from this has emerged the generally accepted definition as an area to which at least two species are endemic. Protocols for locating areas of Endemism have been neglected, and to date no attempt has been made to develop optimality criteria against which to evaluate competing hypotheses of areas of Endemism. Here various protocols for finding areas of Endemism are evaluated-protocols based on both phenetic and parsimony analyses, on both unweighted data and data weighted by various criteria. The optimality criteria used to compare the performance of the methods include the number of species included in the areas of Endemism, the number of areas delim- ited, and the degree of distributional congruency of the species restricted to each area of Endemism. These methods are applied to the African Restionaceae in the Cape Floristic Region. Parsimony meth- ods using weighted data are shown to perform best on the combination of all three optimality criteria. By varying the weighting parameters, the size of the areas of Endemism can be varied. This provides a very useful tool for locating areas of Endemism that satisfy prespecified scale criteria. (Area of en- demism; biogeography; Cape Floristic Region; centers of Endemism; parsimony analysis of Endemism; Restionaceae.) Areas of Endemism are central to the study of historical biogeography (Henderson, 1991). In the search for explanations of earth history based on biological patterns, ar- eas of Endemism are the entities compared. Nelson and Platnick (1981:56) stated, "The most elementary questions of historical bio- geography concern areas of Endemism and their relationships." By analogy to phyloge- netic systematics, where species or higher taxa are grouped, in cladistic biogeography the units grouped are areas of Endemism. Humphries and Parenti (1999) maintained the same position almost 20 years later, when they described the basic question addressed in cladistic biogeography by asking, "Are areas of Endemism interrelated among them- selves in a way analogous to the interrela- tionships of the species of a certain group of organisms?" Areas of Endemism are proba- bly less important in the branch of histori- cal biogeography that seeks a geographical history of a particular taxon (Hovenkamp, 1997), because the distributions of individ- ual species can be used instead of areas of Endemism. Even so, using areas of en- demism, rather than distributions of individ-
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Endemism in the australian flora
Journal of Biogeography, 2001Co-Authors: Michael D Crisp, H P Linder, Shawn W Laffan, A MonroAbstract:Aim To detect centres of vascular plant Endemism at a continental scale by analysis of specimen-based distributional data and to relate any pattern to environmental factors and history. Location Australia. Methods Presence of 8468 seed plant species-level taxa throughout continental Australia and Tasmania was mapped on a 1∞ grid to visualize the pattern of species richness. This sample comprises half the known flora. Three indices of Endemism were calculated but we preferred one that is unrelated to species richness, so that these two concepts could be distinguished in practice. Centres of Endemism were detected by simple mapping and by spatial autocorrelation analysis (SAC). Linear regression was used to examine the relationship of the patterns of species richness and Endemism to latitude, topography and climate. Results Both species richness and Endemism vary greatly across the continent but in most cases the same centres were high in both richness and Endemism. Twelve distinct centres were identified. The major centres of both diversity and Endemism are south-west western Australia, the Border Ranges between New South Wales and Queensland, the Wet Tropics near Cairns, Tasmania and the Iron-McIlwraith Range of eastern Cape York Peninsula. The last centre appears to be more significant than recognized by past authors. Whether this is a true Australian centre of Endemism, or is largely an outlier of the flora of Papua New Guinea, is explored. Another centre, in the Adelaide‐Kangaroo Island region, has been overlooked altogether by previous authors. Regression analysis did not find a simple climatic explanation of the observed patterns. There was a suggestion that topographic variation within the 1∞ cells may be positively correlated with Endemism, which is consistent with mountainous regions functioning as refugia. One clear result is that all the major centres of Endemism are near-coastal. A likely explanation is that Pleistocene expansions of the central desert have been a powerful limitation on the viability of refugia for narrowly endemic species. All the centres of Endemism lie outside the estimated limits of the expanded arid zone at the last glacial maximum (18,000 yr BP). In particular, the ‘Central Australian Mountain Ranges centre of plant diversity and Endemism’ of Boden & Given (1995) is detected as a strong centre of species richness, but not at all as a centre of Endemism. This is despite good sampling of this region. Main conclusions Endemism can be distinguished from species richness by using an appropriate index and mapping of such indices can detect centres of Endemism. This study demonstrates the value of specimen based distributional data, such as is held in state herbaria and museums.
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plant diversity and Endemism in sub saharan tropical africa
Journal of Biogeography, 2001Co-Authors: H P LinderAbstract:Aim This paper has as its central aim the location of centres of species richness and Endemism in the sub-Saharan African flora. Previous postulation of these centres has been based on an intuitive interpretation of distributional data; this paper provides a test of these centres. A second aim is to establish whether the two indices, richness and Endemism, locate the same centres. Thirdly the relationship between species richness and Endemism, and latitude and rainfall are explored. Location The study area includes much of sub-Saharan Africa, but excludes the species-poor southern margin of the Sahara and the Namib–Kalahari regions. Methods Analyses were based on 1818 species, scored on a 2.5 × 2.5 degree grid. Species richness was inferred from a simple grid-diversity count; Endemism was determined by three measures: the number of species restricted to two grids, the sum of the inverse of the ranges of the component species of each grid, and the proportion of the species in each grid that have restricted ranges. Results The African flora shows a remarkably profound patterning, both in species richness and Endemism. The two measures locate largely the same centres, although the rank order among them differs. These centres are: the Cape Floristic Region, East Coast, Congo-Zambezi watershed, Kivu, Upper and Lower Guinea. Richness is strongly related to maximum rainfall, but there are no obvious correlations between modern climate and Endemism. Species richness and Endemism north of the equator is much more concentrated into centres than south of the equator. Main conclusions There are strongly developed refugia in sub-Saharan Africa. North of the equator, these refugia are sharply delimited and rather small, separated by large areas of very low Endemism. South of the equator Endemism tends to be more generally distributed. Variation in species richness in sub-Saharan Africa can be explained largely by modern rainfall, while Endemism may be related to palaeoclimatic fluctuations. Both species richness and Endemism show a strong skewing towards the south, indicating that the fluctuations in the Sahara might have influenced the modern distribution of plants in Africa.
Michael D Crisp - One of the best experts on this subject based on the ideXlab platform.
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phylogenetic Endemism a new approach for identifying geographical concentrations of evolutionary history
Molecular Ecology, 2009Co-Authors: Dan F. Rosauer, Michael D Crisp, Shawn W Laffan, Stephen C Donnellan, Lynette Gai CookAbstract:We present a new, broadly applicable measure of the spatial restriction of phylogenetic diversity, termed phylogenetic Endemism (PE). PE combines the widely used phylogenetic diversity and weighted Endemism measures to identify areas where substantial components of phylogenetic diversity are restricted. Such areas are likely to be of considerable importance for conservation. PE has a number of desirable properties not combined in previous approaches. It assesses Endemism consistently, independent of taxonomic status or level, and independent of previously defined political or biological regions. The results can be directly compared between areas because they are based on equivalent spatial units. PE builds on previous phylogenetic analyses of Endemism, but provides a more general solution for mapping Endemism of lineages. We illustrate the broad applicability of PE using examples of Australian organisms having contrasting life histories: pea-flowered shrubs of the genus Daviesia (Fabaceae) and the Australian species of the Australo-Papuan tree frog radiation within the family Hylidae.
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assessing Endemism at multiple spatial scales with an example from the australian vascular flora
Journal of Biogeography, 2003Co-Authors: Shawn W Laffan, Michael D CrispAbstract: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.
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Endemism in the australian flora
Journal of Biogeography, 2001Co-Authors: Michael D Crisp, H P Linder, Shawn W Laffan, A MonroAbstract:Aim To detect centres of vascular plant Endemism at a continental scale by analysis of specimen-based distributional data and to relate any pattern to environmental factors and history. Location Australia. Methods Presence of 8468 seed plant species-level taxa throughout continental Australia and Tasmania was mapped on a 1∞ grid to visualize the pattern of species richness. This sample comprises half the known flora. Three indices of Endemism were calculated but we preferred one that is unrelated to species richness, so that these two concepts could be distinguished in practice. Centres of Endemism were detected by simple mapping and by spatial autocorrelation analysis (SAC). Linear regression was used to examine the relationship of the patterns of species richness and Endemism to latitude, topography and climate. Results Both species richness and Endemism vary greatly across the continent but in most cases the same centres were high in both richness and Endemism. Twelve distinct centres were identified. The major centres of both diversity and Endemism are south-west western Australia, the Border Ranges between New South Wales and Queensland, the Wet Tropics near Cairns, Tasmania and the Iron-McIlwraith Range of eastern Cape York Peninsula. The last centre appears to be more significant than recognized by past authors. Whether this is a true Australian centre of Endemism, or is largely an outlier of the flora of Papua New Guinea, is explored. Another centre, in the Adelaide‐Kangaroo Island region, has been overlooked altogether by previous authors. Regression analysis did not find a simple climatic explanation of the observed patterns. There was a suggestion that topographic variation within the 1∞ cells may be positively correlated with Endemism, which is consistent with mountainous regions functioning as refugia. One clear result is that all the major centres of Endemism are near-coastal. A likely explanation is that Pleistocene expansions of the central desert have been a powerful limitation on the viability of refugia for narrowly endemic species. All the centres of Endemism lie outside the estimated limits of the expanded arid zone at the last glacial maximum (18,000 yr BP). In particular, the ‘Central Australian Mountain Ranges centre of plant diversity and Endemism’ of Boden & Given (1995) is detected as a strong centre of species richness, but not at all as a centre of Endemism. This is despite good sampling of this region. Main conclusions Endemism can be distinguished from species richness by using an appropriate index and mapping of such indices can detect centres of Endemism. This study demonstrates the value of specimen based distributional data, such as is held in state herbaria and museums.