Nestedness is an important part of the theoretical framework of island biogeography and community ecology.However,most previous studies focused on taxonomic dimension and overlooked functional and phylogenetic nestedn...Nestedness is an important part of the theoretical framework of island biogeography and community ecology.However,most previous studies focused on taxonomic dimension and overlooked functional and phylogenetic nestedness.Here,we simultaneously investigated taxonomic,functional,and phylogenetic nestedness of terrestrial mammals on 39 land-bridge islands in the Zhoushan Archipelago,China.As mammals’response to the environment may depend on their body size,we performed analyses for three mammal assemblages separately:overall species,large and medium-sized species,and small species.The taxonomic nestedness was quantified by organizing the species incidence matrix,while the functional and phylogenetic nestedness were estimated by combining the similarity of their ecological traits and phylogeny.Island characteristics(island area,three isolation indices,land use intensity,and habitat diversity)and species traits(body size,litter size,habitat specificity,geographic range size,and minimum area requirement)were used as predictors of nestedness.Overall and small species were significantly nested in 3 facets of nestedness,and results supported the selective extinction,selective colonization,and habitat nestedness hypotheses.Large and medium-sized species were functionally and phylogenetically nested when matrices were ordered by increasing distance to mainland,supporting the selective colonization hypothesis.Overall,differences in nestedness and its underlying mechanisms were detected not only in 3 facets of nestedness but also in the 3 mammal assemblages.Therefore,frameworks that incorporate taxonomic,phylogenetic,and functional nestedness can contribute to a more comprehensive understanding of nestedness processes.Additionally,it also improves our ability to understand the divergent responses of mammal assemblages to the insular environment.展开更多
Nestedness is one of the important patterns in island biogeography,community ecology and conservation biology.However,most previous nestedness studies focus on the taxonomic dimension while neglecting the functional a...Nestedness is one of the important patterns in island biogeography,community ecology and conservation biology.However,most previous nestedness studies focus on the taxonomic dimension while neglecting the functional and phylogenetic processes in generating nestedness.Moreover,few studies have examined the seasonal change of the nestedness and underlying processes.Here,we examined the seasonal nestedness of bird assemblages in taxonomic,functional,and phylogenetic dimensions,and determined the underlying processes of nestedness patterns in the Zhoushan Archipelago,China.We surveyed the occurrence, abundance,and habitats of birds on 40 islands.We calculated taxonomic,functional,and phylogenetic nestedness using WNODF and treeNODF.We determined the processes underlying nestedness by relating nestedness ranks to island characteristics and species traits.The WNODF analyses showed that bird assemblages in winter and summer were both significantly nested.The habitat-by-site matrix was also significantly nested.The nestedness of bird assemblages was significantly correlated with island area,habitat diversity,habitat specificity,minimum area requirement,habitat specificity and hand-wing index(HWI) of birds in both seasons.While the distance to the nearest mainland(DTM) exerted the influence on nestedness in summer,the distance to the nearest larger island(DTNL)affected nestedness only in winter.However,the nestedness of bird assemblages was not caused by passive sampling or human disturbance.The results of treeNODF analyses illustrated that bird assemblages were functionally and phylogenetically nested in summer and winter,but the exact mechanisms were somewhat different in these two seasons.Overall,our results supported the habitat nestedness hypothesis,selective extinction hypothesis,and selective colonization hypothesis in both seasons.From a conservation viewpoint,we should protect islands with large area and diverse habitats,islands close to the mainland,and species with large area requirement and high habitat specificity to prevent local extinction.展开更多
基金supported by the National Natural Science Foundation of China(32271734 and 31971545).
文摘Nestedness is an important part of the theoretical framework of island biogeography and community ecology.However,most previous studies focused on taxonomic dimension and overlooked functional and phylogenetic nestedness.Here,we simultaneously investigated taxonomic,functional,and phylogenetic nestedness of terrestrial mammals on 39 land-bridge islands in the Zhoushan Archipelago,China.As mammals’response to the environment may depend on their body size,we performed analyses for three mammal assemblages separately:overall species,large and medium-sized species,and small species.The taxonomic nestedness was quantified by organizing the species incidence matrix,while the functional and phylogenetic nestedness were estimated by combining the similarity of their ecological traits and phylogeny.Island characteristics(island area,three isolation indices,land use intensity,and habitat diversity)and species traits(body size,litter size,habitat specificity,geographic range size,and minimum area requirement)were used as predictors of nestedness.Overall and small species were significantly nested in 3 facets of nestedness,and results supported the selective extinction,selective colonization,and habitat nestedness hypotheses.Large and medium-sized species were functionally and phylogenetically nested when matrices were ordered by increasing distance to mainland,supporting the selective colonization hypothesis.Overall,differences in nestedness and its underlying mechanisms were detected not only in 3 facets of nestedness but also in the 3 mammal assemblages.Therefore,frameworks that incorporate taxonomic,phylogenetic,and functional nestedness can contribute to a more comprehensive understanding of nestedness processes.Additionally,it also improves our ability to understand the divergent responses of mammal assemblages to the insular environment.
基金supported by the National Natural Science Foundation of China (32271734)。
文摘Nestedness is one of the important patterns in island biogeography,community ecology and conservation biology.However,most previous nestedness studies focus on the taxonomic dimension while neglecting the functional and phylogenetic processes in generating nestedness.Moreover,few studies have examined the seasonal change of the nestedness and underlying processes.Here,we examined the seasonal nestedness of bird assemblages in taxonomic,functional,and phylogenetic dimensions,and determined the underlying processes of nestedness patterns in the Zhoushan Archipelago,China.We surveyed the occurrence, abundance,and habitats of birds on 40 islands.We calculated taxonomic,functional,and phylogenetic nestedness using WNODF and treeNODF.We determined the processes underlying nestedness by relating nestedness ranks to island characteristics and species traits.The WNODF analyses showed that bird assemblages in winter and summer were both significantly nested.The habitat-by-site matrix was also significantly nested.The nestedness of bird assemblages was significantly correlated with island area,habitat diversity,habitat specificity,minimum area requirement,habitat specificity and hand-wing index(HWI) of birds in both seasons.While the distance to the nearest mainland(DTM) exerted the influence on nestedness in summer,the distance to the nearest larger island(DTNL)affected nestedness only in winter.However,the nestedness of bird assemblages was not caused by passive sampling or human disturbance.The results of treeNODF analyses illustrated that bird assemblages were functionally and phylogenetically nested in summer and winter,but the exact mechanisms were somewhat different in these two seasons.Overall,our results supported the habitat nestedness hypothesis,selective extinction hypothesis,and selective colonization hypothesis in both seasons.From a conservation viewpoint,we should protect islands with large area and diverse habitats,islands close to the mainland,and species with large area requirement and high habitat specificity to prevent local extinction.
