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Response of Distribution Range Against Climate Change and Habitat Preference of Four National Protected Diploderma Species in Tibetan Plateau 被引量:1
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作者 Lin SHI Xiudong SHI +5 位作者 Yuning CAO Yayong WU Haijuan WEI youhua chen Ziyan LIAO Yin QI 《Asian Herpetological Research》 SCIE CSCD 2023年第4期319-330,共12页
Understanding the spatial distribution and habitat preference for rare and endangered species are essential for effective conservation practice.We examined the spatial distribution and habitat preference of four Diplo... Understanding the spatial distribution and habitat preference for rare and endangered species are essential for effective conservation practice.We examined the spatial distribution and habitat preference of four Diploderma species(Diploderma drukdaypo,D.laeviventre,D.batangense,and D.vela),which are endemic to the Qinghai-Tibet Plateau and are currently under state protection.We used the ensembles of small models(ESM)approach and predicted potential distribution ranges of the species in current and two future climate scenarios(SSP126 and SSP585).The degree of overlap between the predicted distribution ranges and existing natural reserves was further analyzed.Habitat preference was examined using a paired quadrat method.Our results predicted that D.drukdaypo has a current distribution range of 600 km^(2),which would decrease to 50 km^(2)and 55 km^(2)under the SSP126 and SSP585 respectively.For D.laeviventre,the current distribution range is 817 km^(2),with minimum changes in the two future climate scenarios(774 km^(2)and 902 km^(2)).For D.batangense,the current distribution range is 875 km^(2),which would expand to 1522 km^(2)and 3340 km^(2)in the two future climate scenarios.Similarly for D.vela,the current distribution range is 1369 km^(2),which would change to 1825 km^(2)and 2043 km^(2)respectively under the two future climate scenarios.The effect of protection of current nature reserves are likely low for those species;we found no overlap(D.drukdaypo,D.laeviventre)or little overlap(D.batangense 2.04%–3.56%,D.vela 15.52%–16.87%)between the currently designated protection area and distribution range under current and future climate scenarios.For habitat preference,stones appear to be the critical habitat element for those species although different species had different stone requirements.Taken together,we provided critical information on potential distribution ranges and habitat preference for four endangered Diploderma species,and confirmed the inadequacy of current nature reserves.The establishment of new or expansion of existing nature reserves is urgent for the conservation of those species. 展开更多
关键词 climate change distribution range habitat preference nature reserve REPTILE
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Current climate overrides past climate change in explaining multi-site beta diversity of Lauraceae species in China 被引量:1
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作者 Ziyan Liao youhua chen +10 位作者 Kaiwen Pan Mohammed A.Dakhil Kexin Lin Xianglin Tian Fengying Zhang Xiaogang Wu Bikram Pandey Bin Wang Niklaus E.Zimmermann Lin Zhang Michael P.Nobis 《Forest Ecosystems》 SCIE CSCD 2022年第2期186-199,共14页
Background:We aimed to characterise the geographical distribution of Sørensen-based multi-site dissimilarity(β_(sor))and its underlying true turnover(β_(sim))and nestedness(βsne)components for Chinese Lauracea... Background:We aimed to characterise the geographical distribution of Sørensen-based multi-site dissimilarity(β_(sor))and its underlying true turnover(β_(sim))and nestedness(βsne)components for Chinese Lauraceae and to analyse their relationships to current climate and past climate change.Methods:We used ensembles of small models(ESMs)to map the current distributions of 353 Lauraceae species in China and calculated β_(sor) and its β_(sim) and β_(sne) components.We tested the relationship between β_(sor),β_(sne) and β_(sim) with current climate and past climate change related predictors using a series of simultaneous autoregressive(SAR_(err))models.Results:Spatial distribution of β_(sor)of Lauraceae is positively correlated with latitude,showing an inverse rela-tionship to the latitudinalα-diversity(species richness)gradient.High β_(sor) occurs at the boundaries of the warm temperate and subtropical zones and at the Qinghai-Tibet Plateau due to high β_(sne).The optimized SAR_(err) model explainsβ_(sor) andβ_(sne) well,but notβ_(sim).Current mean annual temperature determinesβ_(sor) and β_(sne) of Lauraceae more than anomalies and velocities of temperature or precipitation since the Last Glacial Maximum.Conclusions:Current low temperatures and high climatic heterogeneity are the main factors explaining the high multi-siteβ-diversity of Lauraceae.In contrast to analyses of the β-diversity of entire species assemblages,studies of single plant families can provide complementary insights into the drivers of β-diversity of evolutionarily more narrowly defined entities. 展开更多
关键词 Biodiversity conservation Current climate Ensemble modelling Multi-siteβ-diversity NESTEDNESS Past climate change True turnover
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A New Species of Microhyla(Amphibia:Anura:Microhylidae)from Langbian Plateau,Central Vietnam 被引量:1
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作者 Van Chung HOANG Mai Anh LUONG +4 位作者 Quang Truong NGUYEN Nikolai L.ORLOV youhua chen Bin WANG Jianping JIANG 《Asian Herpetological Research》 SCIE CSCD 2020年第3期161-182,共22页
We describe a new species,Microh yla hongiaoensis sp.nov.,from Lam Dong Province,southern Vietnam based on morphological data and molecular evidences.The new species is sister to M.pulchella by molecular phylogenetics... We describe a new species,Microh yla hongiaoensis sp.nov.,from Lam Dong Province,southern Vietnam based on morphological data and molecular evidences.The new species is sister to M.pulchella by molecular phylogenetics and also most closely resembles M.pulchella in morphological characteristics,albeit differs from its congeners by a combination of the following morphological features:(1)size medium(SVL 13.6-14.7 mm in males and 18.3-18.6 mm in females);(2)fingers Ⅱ-Ⅳ with small disks,dorsal surface of disks,without median longitudinal groove;(3)webbing formula Ⅰ11/2 Ⅱ1-2 Ⅲ1-21/2Ⅳ21/4-1 Ⅴ;(4)toe disks with dorsal median longitudinal groove;(5)dorsal back without two small black spots;(6)one small black spot adjacent behind the eyes;(7)few small black scapular spots in the flanks-belly and inguinal region;(8)palm with two small metatarsal tubercles;(9)tibiotarsal reaching beyond snout.M.hongiaoensis sp.nov.occurs in evergreen montane tropical forests at an elevation of 1500 m a.s.l. 展开更多
关键词 new species Microhyla Bi Doup-Nui Ba national
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Global environment- and space-richness ranking relationships: The effects of interaction and high-order terms of explanatory variables
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作者 youhua chen 《Open Journal of Ecology》 2013年第6期389-394,共6页
In the present study, the interplay and higher-order terms of environmental and spatial variables are considered to evaluate the relations of environment and space-species richness rankings at global scale. Three taxo... In the present study, the interplay and higher-order terms of environmental and spatial variables are considered to evaluate the relations of environment and space-species richness rankings at global scale. Three taxonomic groups composed of mammals, birds and amphibians were analyzed for the study. Thek-means clustering method was introduced for richness rankings detection and analysis from published digital maps;and simple regression analysis and AIC criteria were used for identifying mostimportant correlated explanatory variables.When comparing each single variable, I found that latitude was the most important one influencing global vertebrate richness rankings. When onlyconsidering environmental variables, I foundthat precipitation was the only predictor of vertebrate richness rankings. However, when the interaction and high-order terms of different independent variables were considered, it was found that the interaction between latitude and temperature could better explain the global bird richness ranking, while the second-power effectof latitude was the best predictor for amphibianand mammalian richness rankings, as evidenced by the AIC model selection and comparison among the regression models. In conclusion, the inclusion of high-order and interaction terms of environmental and spatial variables could offer more insights into the understanding of global species diversity patterns. 展开更多
关键词 Global Species Distribution NONLINEARITY Richness RANKING Diversity Mapping Environment ENVELOPE
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On the historical biogeography of global Galliformes:ancestral range and diversification patterns
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作者 youhua chen 《Chinese Birds》 CSCD 2014年第1期15-20,共6页
Background: In this study, the ancestral distributional ranges and the tempo of diversification patterns of global Galliformes were investigated.Methods: Different diversification models characterizing possible tempo ... Background: In this study, the ancestral distributional ranges and the tempo of diversification patterns of global Galliformes were investigated.Methods: Different diversification models characterizing possible tempo patterns were fitted and compared onto the phylogenetic tree for the 197 Galliforme species, consisting of a constant-speciation and constant-extinction model(CONSTANT), a decreasing-speciation and constant-extinction model(SPVAR), a constant-speciation and increasing-extinction model(EXVAR) and a decreasing-speciation and increasing-extinction model(BOTHVAR).Ancestral range reconstruction was conducted using the dispersal-extinction-cladogenesis model.Results: A constant-diversification-rate(CONSTANT) model best quantified the historical speciation patterns of this avian assemblage through model selection. Clade age and species richness are significantly and positively correlated. The most recent common ancestor for Galliformes species was originally found in the disjunctive regions between Southeast Asia and North America. High-frequency dispersal events were identified across the whole evolutionary time.Conclusions: The constant diversification rate for global Galliforme species implied that there were no diversification rate-shifting trends for Galliformes species. The present study may contribute to the understanding of the ecology and diversity patterns of Galliformes from the perspective of historical biogeography, although some limitations existed. 展开更多
关键词 Game BIRDS Macro-evolution Rate SHIFTING ZOOGEOGRAPHY PHYLOGENETICS
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Geographical patterns and determinants of insect biodiversity in China
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作者 Huizhong Fan Tongyi Liu +5 位作者 youhua chen Ziyan Liao Jun chen Yibo Hu Gexia Qiao Fuwen Wei 《Science China(Life Sciences)》 SCIE CAS CSCD 2024年第6期1255-1265,共11页
Insects play important roles in the maintenance of ecosystem functioning and the provision of livelihoods for millions of people.However,compared with terrestrial vertebrates and angiosperms,such as the giant panda,cr... Insects play important roles in the maintenance of ecosystem functioning and the provision of livelihoods for millions of people.However,compared with terrestrial vertebrates and angiosperms,such as the giant panda,crested ibis,and the metasequoia,insect conservation has not attracted enough attention,and a basic understanding of the geographical biodiversity patterns for major components of insects in China is lacking.Herein,we investigated the geographical distribution of insect biodiversity across multiple dimensions(taxonomic,genetic,and phylogenetic diversity)based on the spatial distribution and molecular DNA sequencing data of insects.Our analysis included 18 orders,360 families,5,275 genera,and 14,115 species of insects.The results revealed that Southwestern and Southeastern China harbored higher insect biodiversity and numerous older lineages,representing a museum,whereas regions located in Northwestern China harbored lower insect biodiversity and younger lineages,serving as an evolutionary cradle.We also observed that mean annual temperature and precipitation had significantly positive effects,whereas altitude had significantly negative effects on insect biodiversity in most cases.Moreover,cultivated vegetation harbored the highest insect taxonomic and phylogenetic diversity,and needleleaf and broadleaf mixed forests harbored the highest insect genetic diversity.These results indicated that human activities may positively contribute to insect spatial diversity on a regional scale.Our study fills a knowledge gap in insect spatial diversity in China.These findings could help guide national-level conservation plans and the post-2020 biodiversity conservation framework. 展开更多
关键词 insect spatial patterns multiple dimensions driving factors vegetation types
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Topographic heterogeneity and temperature amplitude explain species richness patterns of birds in the Qinghai-Tibetan Plateau 被引量:2
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作者 Chunlan ZHANG Qing QUAN +4 位作者 Yongjie Wu youhua chen Peng HE Yanhua Qu Fumin LEI 《Current Zoology》 SCIE CAS CSCD 2017年第2期131-137,共7页
Large-scale patterns of species richness have gained much attention in recent years; however, the factors that drive high species richness are still controversial in local regions, especially in highly diversified mon... Large-scale patterns of species richness have gained much attention in recent years; however, the factors that drive high species richness are still controversial in local regions, especially in highly diversified montane regions. The Qinghai-Tibetan Plateau (QTP) and the surrounding mountains are biodiversity hot spots due to a high number of endemic montane species. Here, we explored the fac- tors underlying this high level of diversity by studying the relationship between species richness and environmental variables. The richness patterns of 758 resident bird species were summarized at the scale of 1°× 1° grid cell at different taxonomic levels (order, family, genus, and species) and in differ- ent taxonomic groups (Passeriformes, Galliformes, Falconiformes, and Columbiformes). These rich- ness patterns were subsequently analyzed against habitat heterogeneity (topographical heterogen- eity and land cover), temperature amplitude (annual temperature, annual precipitation, precipitation seasonality, and temperature seasonality) and a vegetation index (net primary productivity). Our re- sults showed that the highest richness was found in the southeastern part of the QTP, the eastern Himalayas. The lowest richness was observed in the central plateau of the QTP. Topographical het- erogeneity and temperature amplitude are the primary factors that explain overall patterns of species richness in the QTP, although the specific effect of each environmental variable varies between the different taxonomic groups depending on their own evolutionary histories and ecological require- ments. High species richness in the southeastern QTP is mostly due to highly diversified habitat types and temperature zones along elevation gradients, whereas the low species richness in the cen- tral plateau of the QTP may be due to environmental and energetic constraints, as the central plateau is harsh environment. 展开更多
关键词 BIRDS habitat heterogeneity Oinghai-Tibetan plateau species richness temperature amplitude topography.
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Inpatient bed allocation policy under uncertain capacity 被引量:1
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作者 Xing Liu youhua chen +3 位作者 Li Luo Ting Zhu Wenwu Shen TAIWO Enayon Sunday 《Journal of Management Science and Engineering》 2019年第4期228-251,共24页
This paper concerns the problem of inpatient bed allocation for two classes of patients(scheduled and non-scheduled)when there is uncertainty about daily available capacity.In the afternoon of each day,patients from t... This paper concerns the problem of inpatient bed allocation for two classes of patients(scheduled and non-scheduled)when there is uncertainty about daily available capacity.In the afternoon of each day,patients from the scheduled class,also called backlogged elective admissions,are selected from a waiting list,for the admission on the next day.The non-scheduled class,also called emergent admissions,are new requests that arise randomly each day with emergent needs.The capacity of available beds for a medical specialty to provide hospitalization services is uncertain when backlogged elective pa-tients are chosen.Admitting too many of elective patients may result in exceeding a day’s capacity,which can potentially necessitate"overflowing"or"postponing"some emergent requests that should be performed as soon as possible.Therefore,the problem faced by the medical specialty facility at the decision-making point of each day is how many of the backlogged elective patients can be admitted.We formulate this problem as a Markov decision process(MDP)and study the structural properties of the model to characterize the nature of the optimal policy.We propose easy-to-implement policies(the fixed quota policy and the best fixed quota policy),which perform well under fitted distributions.By reporting numerical analyses using real data from a Chinese public hospital,we finally compare the improvements that our proposed solutions could bring to the hospital with the existing practices under several different cost structures. 展开更多
关键词 Bed allocation Markov decision process Emergency reservation Healthcare management
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Conservation priority of global Galliformes species based on phylogenetic diversity
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作者 youhua chen 《Integrative Zoology》 SCIE CSCD 2014年第3期340-348,共9页
In this study,based on phylogenetic diversity(PD),I develop a conservation strategy for Galliformes species around the world.A cladogram of 197 Galliformes species derived from a previous study was used for calculat&#... In this study,based on phylogenetic diversity(PD),I develop a conservation strategy for Galliformes species around the world.A cladogram of 197 Galliformes species derived from a previous study was used for calculat­ing PD metrics.Branch length is an important aspect of the phylogenetic information a tree can convey,but 2 traditionally-used metrics,the number of phylogenetic groups to which a taxon belongs(I)and the proportion that each taxon contributes to the total diversity of the group(W),are fully node-based and do not take branch length into account.Therefore,to measure PD more appropriately,I combined a branch-related metric,pen­dant edge(P),in addition to I and W.A final combined rank for Galliformes species was obtained by summing the ranks of the 3 metrics.My results showed that the 5%top priority species for conserving evolutionary po­tential were Galloperdix lunulata,Haematortyx sanguiniceps,Margaroperdix madagarensis,Syrmaticus soem­merringii,Coturnix pectoralis,Polyplectron napoleonis,Alectoris melanocephala,Xenoperdix udzungwensis,Afropavo congensis and Syrmaticus reevesii.The current species priority ranking based on pylogenetic diversi­ty and the official International Union for Conservation of Nature(IUCN)ranking of Galliformes species was significantly correlated when considering the 5 categories of IUCN(critical endangered,endangered,vulnera­ble,near threatened and least concern).This indicated the feasibility of introducing the PD index into the net­work of IUCN regional Red List assessment.The 5%top priority countries selected using the complementarity principle possessing diversified Galliformes genetic resources were China,Indonesia,Mexico,India,Colombia,Australia,Brazil,Angola,Congo and Japan(in descending order).China,Indonesia,Mexico,Brazil,India and Colombia are consistently selected among the 4 top priority sets of richness,rarity,endemicity and PD.This re­sult indicated that the priority result from PD is highly congruent with conventional measures.Along with oth­er conventional ecological attributes,the alternative conservation scenario based on PD is reasonable and can be adopted in systematic conservation planning. 展开更多
关键词 complementarity conservation priority evolutionary history IUCN Red List
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Global potential distribution of an invasive species,the yellow crazy ant(Anoplolepis gracilipes)under climate change
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作者 youhua chen 《Integrative Zoology》 SCIE CSCD 2008年第3期166-175,共10页
Changes to the Earth’s climate may affect the distribution of countless species. Understanding the potentialdistribution of known invasive species under an altered climate is vital to predicting impacts and developin... Changes to the Earth’s climate may affect the distribution of countless species. Understanding the potentialdistribution of known invasive species under an altered climate is vital to predicting impacts and developingmanagement policy. The present study employs ecological niche modeling to construct the global potential distributionrange of the yellow crazy ant (Anoplolepis gracilipes) using past, current and future climate scenarios.Three modeling algorithms, GARP, BioClim and Environmental Distance, were used in a comparative analysis.Output from the models suggest firstly that this insect originated from south Asia, expanded into Europe and theninto Afrotropical regions, after which it formed its current distribution. Second, the invasive risk of A. gracilipesunder future climatic change scenarios will become greater because of an extension of suitable environmentalconditions in higher latitudes. Third, when compared to the GARP model, BioClim and Environmental Distancemodels were better at modeling a species’ ancestral distribution. These findings are discussed in light of thepredictive accuracy of these models. 展开更多
关键词 Anoplolepis gracilipes BIOCLIM ecological niche modeling Environmental Distance GARP
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Biotic element analysis of reptiles of China: A test of vicariance model
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作者 youhua chen 《Current Zoology》 SCIE CAS CSCD 2013年第4期449-457,共9页
In this contribution, I identify possible biotic elements of reptiles of China using biotic element analysis. I test whether the vicariance model could significantly shape reptilian current distribution patterns. My r... In this contribution, I identify possible biotic elements of reptiles of China using biotic element analysis. I test whether the vicariance model could significantly shape reptilian current distribution patterns. My results show that dispersal is prevailing for reptiles in China. There are four major biotic elements in reptilian distribution, which are East Xizang, Yunnan- Guizhou Plateau, Taiwan and Hainan, respectively. The test of distributional areas is significantly more clustered than expected by chance, while in another test that closely related species are homogeneously distributed across biotic elements cannot be rejected. Therefore I argued that vicariance might be one of the key processes in patterning reptilian distribution in China. In addition, I develop an improved biotic element analysis in biogeographic studies, by performing biotic element analysis in an iterative man- ner in order to diagnose more geographically restricted elements until no noise components found. The importance of antecedent selection of distributional data for the subsequent analysis is also discussed. Besides, my study indicates that biodiversity hotspots are not fully overlapped with areas of endemism for reptilians in East Asia 展开更多
关键词 Biotic element analysis reptilian fauna BIOGEOGRAPHY null model
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Does the diversification rate of endemic birds of China's Mainland follow abrupt,gradual shifting or constant patterns?
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作者 youhua chen 《Integrative Zoology》 SCIE CSCD 2017年第2期165-171,共7页
In this brief report,time-varying(including both gradual and abrupt change)and time-constant diversification models are fitted on a phylogeny of endemic birds of China's Mainland to test the diversification patter... In this brief report,time-varying(including both gradual and abrupt change)and time-constant diversification models are fitted on a phylogeny of endemic birds of China's Mainland to test the diversification patterns of endemic birds in the region.The results show that phylogeny of endemic birds is best quantified by a constant-rate diversification model through model comparison.Limitations of the study are discussed.In particular,ignorance of non-endemic taxa and the limited sampling of endemic taxa could influence the conclusions of the study. 展开更多
关键词 adaptive evolution avian endemism diversification analysis MACROEVOLUTION
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Open life science research,open software and the open century
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作者 youhua chen 《Journal of Coastal Life Medicine》 2015年第5期414-415,共2页
At the age of knowledge explosion and mass scientific information,I highlighted the importance of conducting open science in life and medical researches through the extensive usage of open software and documents.The p... At the age of knowledge explosion and mass scientific information,I highlighted the importance of conducting open science in life and medical researches through the extensive usage of open software and documents.The proposal of conducting open science is to reduce the limited repeatability of researches in life science.I outlined the essential steps for conducting open life science and the necessary standards for creating,reusing and reproducing open materials.Different Creative Commons licenses were presented and compared of their usage scope and restriction.As a conclusion,I argued that open materials should be widely adopted in doing life and medical researches. 展开更多
关键词 Open science Open software CREATIVE Commons licenses Online database
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An island biogeography model for beta diversity and endemism: The roles of speciation, extinction and dispersal
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作者 youhua chen 《International Journal of Biomathematics》 2015年第1期137-148,共12页
A community composition island biogeography model was developed to explain and predict two community patterns (beta diversity and endemism) with the consideration of speciation, extinction and dispersal processes. R... A community composition island biogeography model was developed to explain and predict two community patterns (beta diversity and endemism) with the consideration of speciation, extinction and dispersal processes. Results showed that rate of speciation is positively and linearly associated with beta diversity and endemism, that is, increasing species rates typically could increase the percentage of both endemism and beta diversity. The influences of immigration and extinction rates on beta diversity and endemism are nonlinear, but with numerical simulation, I could observe that increasing extinction rates would lead to decreasing percentage of endemism and beta diversity. The role of immigration rate is very similar to that of speciation rate, having a positive relationship with beta diversity and endemism. Finally, I found that beta diversity is closely related to the percentage of endemism. The slope of this positive relationship is determined jointly by different combinations of speciation, extinction and immigration rates. 展开更多
关键词 Island biogeography model composition patterns ENDEMISM TURNOVER
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