Beta diversity,the variation of community composition among sites,bridges alpha and gamma diversity and can reveal the mechanisms of community assembly through applying distance-decay models and/or partitioning beta d...Beta diversity,the variation of community composition among sites,bridges alpha and gamma diversity and can reveal the mechanisms of community assembly through applying distance-decay models and/or partitioning beta diversity into turnover and nestedness components from functional and phylogenetic perspectives.Mountains as the most natural experiment system provide good opportunities for exploring beta diversity patterns and the underlying ecological processes.Here,we simultaneously consider distance-decay models and multiple di-mensions of beta diversity to examine spatial variations of bird communities,and to evaluate the relative importance of niche-based and neutral community assembly mechanisms along a 3600-m elevational gradient in the central Himalayas,China.Our results showed that species turnover dominates taxonomic,functional,and phylogenetic beta diversity.We observed strongest evidence of spatial distance decays in taxonomic similarities of birds,followed by its phylogenetic and functional analogues.Turnover component was highest in taxonomic beta diversity,while nestedness component was highest in functional beta diversity.Further,all correlations of assemblage similarity with climatic distance were higher than that with spatial distances.Standardized values of overall taxonomic,functional,and phylogenetic beta diversity and their turnover components increase with increasing elevational distance,while the standardized values of taxonomic and phylogenetic nestedness decreased with increasing elevational distance.Our results highlighted the niche-based deterministic processes in shaping elevational bird diversity patterns that were determined by the relative roles of decreasing trend of environmental filtering and increasing trend of limiting similarity along elevation distances.展开更多
Mixed-species flocks of birds are distributed world-wide and can be especially dominant in temperate forests during the non-breeding season and in tropical rainforests year-round.We review from a community ecology per...Mixed-species flocks of birds are distributed world-wide and can be especially dominant in temperate forests during the non-breeding season and in tropical rainforests year-round.We review from a community ecology perspective what is known about the structure and organization of flocks,emphasizing that flocking species tend to be those particularly vulnerable to predation,and flocks tend to be led by species that are able to act as sources of information about predators for other species.Studies on how flocks respond to fragmentation and land-use intensification continue to accumulate,but the question of whether the flock phenomenon makes species more vulnerable to anthropogenic change remains unclear.We review the literature on flocks in East Asia and demonstrate there is a good foundation of knowledge on which to build.We then outline potentially fruitful future directions,focusing on studies that can investigate how dependent species are on each other in flocks,and how such interdependencies might affect avian habitat selection in the different types of human-modified environments of this region.展开更多
Brood parasites such as the common cuckoo Cuculus canorus exploit the parental abilities of their hosts,hosts avoid brood parasitism and predation by showing specific behavior such as loss of feathers,emission of fear...Brood parasites such as the common cuckoo Cuculus canorus exploit the parental abilities of their hosts,hosts avoid brood parasitism and predation by showing specific behavior such as loss of feathers,emission of fear screams and contact calls,displaying wriggle behavior to avoid hosts or potential prey,pecking at hosts and prey,and expressing tonic immobility(showing behavior like feigning death or rapid escape from predators and brood parasites).These aspects of escape behavior are consistent for individuals but also among sites,seasons,and years.Escape behavior expressed in response to a broad range of cuckoo hosts and prey are consistently used against capture by humans,but also hosts and brood parasites and predators and their prey.An interspecific comparative phylogenetic analysis of escape behavior by hosts and their brood parasites and prey and their predators revealed evidence of consistent behavior when encountering potential parasites or predators.We hypothesize that personality axes such as those ranging from fearfulness to being bold,and from neophobic to curiosity response in brood parasites constitute important components of defense against brood parasitism that reduces the overall risk of parasitism.展开更多
Reservoir islands formed by dam construction have the same history,clear boundaries,and large numbers that provide a natural platform for testing theories in ecology and biogeography.In this paper,we review studies of...Reservoir islands formed by dam construction have the same history,clear boundaries,and large numbers that provide a natural platform for testing theories in ecology and biogeography.In this paper,we review studies of multiple zoological taxa on reservoir islands of a large lake in eastern China(Thousand Island Lake).This lake,created in 1959,has 1078 artificial land-bridge islands of varying areas and isolation.Our review summarizes the decades-long studies in island biogeography and habitat fragmentation from this island system,grouped into three topics:species richness(“how many species are there”),community structure(“who are they”),and species interaction(“how they interact with each other”).Our findings support the predictions of the Equilibrium Theory of Island Biogeography and extend this theory to predict community structure of island faunas by moving beyond assumptions of species equivalency.In addition,the extensive studies on ecological networks,including mutualistic,antagonistic,and parasitic interactions,reveal the negative impacts of habitat loss on the maintenance of such networks,even as increasing forest edge enhances the robustness of pollination networks.At the end of this review,we proposed several future research directions based on current studies that are simultaneously at the frontier of ecology and biogeography.展开更多
Although egg color polymorphism has evolved as an effective defensive adaptation to brood parasitism,spatial variations in egg color polymorphism remain poorly characterized.Here,we investigated egg polymorphism in 64...Although egg color polymorphism has evolved as an effective defensive adaptation to brood parasitism,spatial variations in egg color polymorphism remain poorly characterized.Here,we investigated egg polymorphism in 647 host species(68 families and 231 gen era)parasitized by 41 species of Old Word cuckoos(1 family and 11 gen era)across Asia,Europe,Africa,and Australia.The diversity of parasitic cuckoos differs among continents,reflecting the continent-specific intensities of parasitic selection pressure on hosts.Therefore,host egg polymorphism is expected to evolve more frequently on continents with higher cuckoo diversity.We identified egg polymorphism in 24.1%of all host species and 47.6%of all host families.The common cuckoo Cuculus canorus utilized 184 hosts(28.4%of all host species).Hosts of the common cuckoo and of Chrysococcyx species were more likely to have polymorphic eggs than hosts parasitized by other cuckoos.Both the number of host species and the host families targeted by the cuckoo species were positively correlated with the frequency of host egg polymorphism.Most host species and most hosts exhibiting egg color polymorphism were located in Asia and Africa.Host egg polymorphism was observed less frequently in Australia and Europe.Our results also suggested that egg polymorphism tends to occur more frequently in hosts that are utilized by several cuckoo species or by generalist cuckoo species.We suggest that selecti on pressure on hosts from a given contin ent in creases proportionally to the number of cuckoo species,and that this selection pressure may,in turn,favor the evolution of host egg polymorphism.展开更多
Biodiversity has been subjected to increasing anthropogenic pressures.It is critical to understand the different processes that govern community assembly and species coexistence under biogeographic processes and anthr...Biodiversity has been subjected to increasing anthropogenic pressures.It is critical to understand the different processes that govern community assembly and species coexistence under biogeographic processes and anthropogenic events.Pheasants(Aves:Phasianidae)are highly threatened birds and China supports the richest pheasant species worldwide.Unravelling the spatial patterns and underlying factors associated with multidimensional biodiversity of species richness(SR),functional diversity(FD),and phylogenetic diversity(PD)of pheasants in China is helpful to understand not only the processes that govern pheasant community assembly and species coexistence,but also pheasant biodiversity conservation.We used a total of 45 pheasant species in China and analyzed the SR,FD,PD,and functional and phylogenetic structures by integrating species distribution maps,functional traits and phylogenies based on 50 km×50 km grid cells.We further used simultaneous autoregressive(SAR)models to explore the factors that determined these patterns.The southern Qinghai-Tibetan Plateau(QTP),Hengduan Mountains,southwestern Mountains,the east of the Qilian Mountains,the Qinling,southern China displayed higher SR,FD,and PD,which were determined by elevation,habitat heterogeneity,temperature seasonality,and vegetation cover.Elevation primarily determined the functional and phylogenetic structures of the pheasant communities.Assemblages in the highlands were marked by functional and phylogenetic clustering,particularly in the QTP,whereas the lowlands in eastern China comprised community overdispersion.Clustered pheasant assemblages were composed of young lineages.Patterns of functional and phylogenetic structures and richness-controlled functional and phylogenetic diversity differed between regions,suggesting that phylogenetic structures are not a good proxy for identifying functional structures.We revealed the significant role of elevation in pheasant community assemblages in China.Highlands interacted with community clustering,whereas lowlands interacted with overdispersion,supporting the environmental filtering hypothesis.Biogeographical drivers other than anthropogenic factor determined biodiversity of pheasants at the present scale of China.This study provides complementary background resources for multi-dimensional pheasant biodiversity and provides insights into avian biodiversity patterns in China.展开更多
Background: Although assessing temporal dynamics of populations is crucial for understanding metacommunities, empirical studies have primarily analyzed only static snapshots of communities. Here, we present a holistic...Background: Although assessing temporal dynamics of populations is crucial for understanding metacommunities, empirical studies have primarily analyzed only static snapshots of communities. Here, we present a holistic view of how species traits and habitat characteristics relate to metacommunity dynamics and use it to test for differences in the spatiotemporal distribution of seasonal bird assemblages. Methods: We surveyed forest birds in breeding and winter seasons within 36 islands for 9 years. We then grouped birds into four landbird assemblages, selected on the basis of published differences in biology or ecology: winter residents, migratory winter visitors, breeding summer residents, and migratory summer visitors. We estimated dynamic species colonization and extirpation through the 9-year period, and evaluated the associations among island attributes, species attributes and community composition. Results: Overall, winter and summer residents showed strong associations between composition and habitat structure of the islands. In addition, winter and summer residents on large islands had lower extirpation and turnover than winter and summer visitors. Visitor assemblages showed no significant habitat associations, and in winter had high extirpation rates and small body sizes. By contrast, local extirpation of summer visitors was correlated with local species richness, indicating a likely effect of competition on extirpation. Conclusions: Our results demonstrated repeated patterns among species composition, bird traits, habitat/island characteristics and observed metacommunity dynamics. Winter and summer residents best matched species sorting and patch dynamics, respectively, due to differences in resource availability and requirements of overwinter survival versus breeding. Summer visitors were consistent with species sorting and winter visitors were randomly distributed, likely because of interactions with resident competitors. Our results highlight that coexisting seasonal migrant and resident assemblages differ in their spatial dynamics, with consequences for relevant conservation and management strategies.展开更多
Habitat fragmentation is a major cause of biodiversity loss.Fragmentation can alter thermal conditions on the remaining patches,especially at habitat edges,but few studies have examined variations in thermal tolerance...Habitat fragmentation is a major cause of biodiversity loss.Fragmentation can alter thermal conditions on the remaining patches,especially at habitat edges,but few studies have examined variations in thermal tolerance of species in fragmented habitats.Ants are sensitive to both habitat fragmentation and temperature changes,and are an ideal taxon for studying these impacts.Here,we focused on the dimorphic ant species Pheidole nodus in a fragmented habitat island system(Thousand island lake)in China.We assessed critical thermal maximum(CTmax),minimum(CTmin),and range(CTrange)temperatures for both minor(workers)and major workers(soldiers)of 2307 individuals from 117 edge and interior colonies across 9 islands during relatively hot and cold seasons.Using mixed-effect linear models,we explored the effects of island area,habitat type(edge vs.interior),season,and caste(worker vs.soldier)on CTmax,CTmin,and CTrange.We found temperatures were 1-3°C higher in edge than interior sites in relatively hot season.Yet,only CTmax and CTrange in edge populations were higher than those of interior sites on smaller islands.CTmax was higher in relatively hot season and CTmin was lower in relatively cold season,indicating seasonal plasticity in thermal tolerance.Workers consistently had higher CTmax and lower CTmin than soldiers.These findings underscore the importance of seasonality,worker caste,and interactive effect between island area and habitat type in shaping thermal tolerance of a dominant dimorphic ant species on fragmented habitat islands.Our study provides a roadmap for integrating thermal biology into studies of how fragmentation impacts biodiversity.展开更多
Impact statement Habitat loss has been a primary threat to biodiversity.However,species do not function in isolation but often associate with each other and form complex networks.Thus,revealing how the network complex...Impact statement Habitat loss has been a primary threat to biodiversity.However,species do not function in isolation but often associate with each other and form complex networks.Thus,revealing how the network complexity and stability scale with habitat area will give us more insights into the effects of habitat loss on ecosystems.In this study,we explored the relationships between the island area and the network complexity and stability of soil microbes.We found that the complexity and stability of soil microbial co‐occurrence networks scale positively with island area,indicating that habitat loss will potentially simplify and destabilize soil microbial networks.展开更多
基金supported by the Key R&D Program of Tibet Auton-omous Region(XZ202301ZY0019G)Project for the Local Development of Science and Technology by the Central Government(XZ202301YD0007C)the National Natural Science Foundation of China(No.31400361).
文摘Beta diversity,the variation of community composition among sites,bridges alpha and gamma diversity and can reveal the mechanisms of community assembly through applying distance-decay models and/or partitioning beta diversity into turnover and nestedness components from functional and phylogenetic perspectives.Mountains as the most natural experiment system provide good opportunities for exploring beta diversity patterns and the underlying ecological processes.Here,we simultaneously consider distance-decay models and multiple di-mensions of beta diversity to examine spatial variations of bird communities,and to evaluate the relative importance of niche-based and neutral community assembly mechanisms along a 3600-m elevational gradient in the central Himalayas,China.Our results showed that species turnover dominates taxonomic,functional,and phylogenetic beta diversity.We observed strongest evidence of spatial distance decays in taxonomic similarities of birds,followed by its phylogenetic and functional analogues.Turnover component was highest in taxonomic beta diversity,while nestedness component was highest in functional beta diversity.Further,all correlations of assemblage similarity with climatic distance were higher than that with spatial distances.Standardized values of overall taxonomic,functional,and phylogenetic beta diversity and their turnover components increase with increasing elevational distance,while the standardized values of taxonomic and phylogenetic nestedness decreased with increasing elevational distance.Our results highlighted the niche-based deterministic processes in shaping elevational bird diversity patterns that were determined by the relative roles of decreasing trend of environmental filtering and increasing trend of limiting similarity along elevation distances.
基金the 1000 Plan Recruitment Program of Global Experts of the People’s Republic of Chinathe Special Talent Recruitment Program of Guangxi University for support
文摘Mixed-species flocks of birds are distributed world-wide and can be especially dominant in temperate forests during the non-breeding season and in tropical rainforests year-round.We review from a community ecology perspective what is known about the structure and organization of flocks,emphasizing that flocking species tend to be those particularly vulnerable to predation,and flocks tend to be led by species that are able to act as sources of information about predators for other species.Studies on how flocks respond to fragmentation and land-use intensification continue to accumulate,but the question of whether the flock phenomenon makes species more vulnerable to anthropogenic change remains unclear.We review the literature on flocks in East Asia and demonstrate there is a good foundation of knowledge on which to build.We then outline potentially fruitful future directions,focusing on studies that can investigate how dependent species are on each other in flocks,and how such interdependencies might affect avian habitat selection in the different types of human-modified environments of this region.
文摘Brood parasites such as the common cuckoo Cuculus canorus exploit the parental abilities of their hosts,hosts avoid brood parasitism and predation by showing specific behavior such as loss of feathers,emission of fear screams and contact calls,displaying wriggle behavior to avoid hosts or potential prey,pecking at hosts and prey,and expressing tonic immobility(showing behavior like feigning death or rapid escape from predators and brood parasites).These aspects of escape behavior are consistent for individuals but also among sites,seasons,and years.Escape behavior expressed in response to a broad range of cuckoo hosts and prey are consistently used against capture by humans,but also hosts and brood parasites and predators and their prey.An interspecific comparative phylogenetic analysis of escape behavior by hosts and their brood parasites and prey and their predators revealed evidence of consistent behavior when encountering potential parasites or predators.We hypothesize that personality axes such as those ranging from fearfulness to being bold,and from neophobic to curiosity response in brood parasites constitute important components of defense against brood parasitism that reduces the overall risk of parasitism.
基金supported by National Natural Science Foundation of China(32030066,32071545,32371590,32301330,32001124,32101268,32101278)。
文摘Reservoir islands formed by dam construction have the same history,clear boundaries,and large numbers that provide a natural platform for testing theories in ecology and biogeography.In this paper,we review studies of multiple zoological taxa on reservoir islands of a large lake in eastern China(Thousand Island Lake).This lake,created in 1959,has 1078 artificial land-bridge islands of varying areas and isolation.Our review summarizes the decades-long studies in island biogeography and habitat fragmentation from this island system,grouped into three topics:species richness(“how many species are there”),community structure(“who are they”),and species interaction(“how they interact with each other”).Our findings support the predictions of the Equilibrium Theory of Island Biogeography and extend this theory to predict community structure of island faunas by moving beyond assumptions of species equivalency.In addition,the extensive studies on ecological networks,including mutualistic,antagonistic,and parasitic interactions,reveal the negative impacts of habitat loss on the maintenance of such networks,even as increasing forest edge enhances the robustness of pollination networks.At the end of this review,we proposed several future research directions based on current studies that are simultaneously at the frontier of ecology and biogeography.
基金We thank Laikun Ma,Tongping Su,and Juan Huo for their assistances.
文摘Although egg color polymorphism has evolved as an effective defensive adaptation to brood parasitism,spatial variations in egg color polymorphism remain poorly characterized.Here,we investigated egg polymorphism in 647 host species(68 families and 231 gen era)parasitized by 41 species of Old Word cuckoos(1 family and 11 gen era)across Asia,Europe,Africa,and Australia.The diversity of parasitic cuckoos differs among continents,reflecting the continent-specific intensities of parasitic selection pressure on hosts.Therefore,host egg polymorphism is expected to evolve more frequently on continents with higher cuckoo diversity.We identified egg polymorphism in 24.1%of all host species and 47.6%of all host families.The common cuckoo Cuculus canorus utilized 184 hosts(28.4%of all host species).Hosts of the common cuckoo and of Chrysococcyx species were more likely to have polymorphic eggs than hosts parasitized by other cuckoos.Both the number of host species and the host families targeted by the cuckoo species were positively correlated with the frequency of host egg polymorphism.Most host species and most hosts exhibiting egg color polymorphism were located in Asia and Africa.Host egg polymorphism was observed less frequently in Australia and Europe.Our results also suggested that egg polymorphism tends to occur more frequently in hosts that are utilized by several cuckoo species or by generalist cuckoo species.We suggest that selecti on pressure on hosts from a given contin ent in creases proportionally to the number of cuckoo species,and that this selection pressure may,in turn,favor the evolution of host egg polymorphism.
基金supported by grants from the National Natural Science Foundation of China(No.31872240)the National Key R&D Plan Project(No.2016YFC0503206)。
文摘Biodiversity has been subjected to increasing anthropogenic pressures.It is critical to understand the different processes that govern community assembly and species coexistence under biogeographic processes and anthropogenic events.Pheasants(Aves:Phasianidae)are highly threatened birds and China supports the richest pheasant species worldwide.Unravelling the spatial patterns and underlying factors associated with multidimensional biodiversity of species richness(SR),functional diversity(FD),and phylogenetic diversity(PD)of pheasants in China is helpful to understand not only the processes that govern pheasant community assembly and species coexistence,but also pheasant biodiversity conservation.We used a total of 45 pheasant species in China and analyzed the SR,FD,PD,and functional and phylogenetic structures by integrating species distribution maps,functional traits and phylogenies based on 50 km×50 km grid cells.We further used simultaneous autoregressive(SAR)models to explore the factors that determined these patterns.The southern Qinghai-Tibetan Plateau(QTP),Hengduan Mountains,southwestern Mountains,the east of the Qilian Mountains,the Qinling,southern China displayed higher SR,FD,and PD,which were determined by elevation,habitat heterogeneity,temperature seasonality,and vegetation cover.Elevation primarily determined the functional and phylogenetic structures of the pheasant communities.Assemblages in the highlands were marked by functional and phylogenetic clustering,particularly in the QTP,whereas the lowlands in eastern China comprised community overdispersion.Clustered pheasant assemblages were composed of young lineages.Patterns of functional and phylogenetic structures and richness-controlled functional and phylogenetic diversity differed between regions,suggesting that phylogenetic structures are not a good proxy for identifying functional structures.We revealed the significant role of elevation in pheasant community assemblages in China.Highlands interacted with community clustering,whereas lowlands interacted with overdispersion,supporting the environmental filtering hypothesis.Biogeographical drivers other than anthropogenic factor determined biodiversity of pheasants at the present scale of China.This study provides complementary background resources for multi-dimensional pheasant biodiversity and provides insights into avian biodiversity patterns in China.
基金supported by National Natural Science Foundation of China(Grants 31210103908 and 31572250 to PD,Grant 31500453 to XS,Grants 31471981 and 31770462 to YW)Jiangsu Postdoctoral Research Foundation(2018K169C)supported by Agricultural Experiment Station to the University of California at Davis
文摘Background: Although assessing temporal dynamics of populations is crucial for understanding metacommunities, empirical studies have primarily analyzed only static snapshots of communities. Here, we present a holistic view of how species traits and habitat characteristics relate to metacommunity dynamics and use it to test for differences in the spatiotemporal distribution of seasonal bird assemblages. Methods: We surveyed forest birds in breeding and winter seasons within 36 islands for 9 years. We then grouped birds into four landbird assemblages, selected on the basis of published differences in biology or ecology: winter residents, migratory winter visitors, breeding summer residents, and migratory summer visitors. We estimated dynamic species colonization and extirpation through the 9-year period, and evaluated the associations among island attributes, species attributes and community composition. Results: Overall, winter and summer residents showed strong associations between composition and habitat structure of the islands. In addition, winter and summer residents on large islands had lower extirpation and turnover than winter and summer visitors. Visitor assemblages showed no significant habitat associations, and in winter had high extirpation rates and small body sizes. By contrast, local extirpation of summer visitors was correlated with local species richness, indicating a likely effect of competition on extirpation. Conclusions: Our results demonstrated repeated patterns among species composition, bird traits, habitat/island characteristics and observed metacommunity dynamics. Winter and summer residents best matched species sorting and patch dynamics, respectively, due to differences in resource availability and requirements of overwinter survival versus breeding. Summer visitors were consistent with species sorting and winter visitors were randomly distributed, likely because of interactions with resident competitors. Our results highlight that coexisting seasonal migrant and resident assemblages differ in their spatial dynamics, with consequences for relevant conservation and management strategies.
基金supported by the National Nature Science Foundation of China(#32101278 and#32261160374)China Postdoctoral Science Foun-dation(#2023M731111).
文摘Habitat fragmentation is a major cause of biodiversity loss.Fragmentation can alter thermal conditions on the remaining patches,especially at habitat edges,but few studies have examined variations in thermal tolerance of species in fragmented habitats.Ants are sensitive to both habitat fragmentation and temperature changes,and are an ideal taxon for studying these impacts.Here,we focused on the dimorphic ant species Pheidole nodus in a fragmented habitat island system(Thousand island lake)in China.We assessed critical thermal maximum(CTmax),minimum(CTmin),and range(CTrange)temperatures for both minor(workers)and major workers(soldiers)of 2307 individuals from 117 edge and interior colonies across 9 islands during relatively hot and cold seasons.Using mixed-effect linear models,we explored the effects of island area,habitat type(edge vs.interior),season,and caste(worker vs.soldier)on CTmax,CTmin,and CTrange.We found temperatures were 1-3°C higher in edge than interior sites in relatively hot season.Yet,only CTmax and CTrange in edge populations were higher than those of interior sites on smaller islands.CTmax was higher in relatively hot season and CTmin was lower in relatively cold season,indicating seasonal plasticity in thermal tolerance.Workers consistently had higher CTmax and lower CTmin than soldiers.These findings underscore the importance of seasonality,worker caste,and interactive effect between island area and habitat type in shaping thermal tolerance of a dominant dimorphic ant species on fragmented habitat islands.Our study provides a roadmap for integrating thermal biology into studies of how fragmentation impacts biodiversity.
基金This research was supported by the National Natural Science Foundation of China(31971553,32222051,and 31361123001)the National Science Foundation of the United States of America(DEB-1342754 and DEB-1856318)+1 种基金the Shanghai Rising-Star ProgramP.W.was supported by the research fund of the post-doctor who came to Shenzhen(szbo202306).
文摘Impact statement Habitat loss has been a primary threat to biodiversity.However,species do not function in isolation but often associate with each other and form complex networks.Thus,revealing how the network complexity and stability scale with habitat area will give us more insights into the effects of habitat loss on ecosystems.In this study,we explored the relationships between the island area and the network complexity and stability of soil microbes.We found that the complexity and stability of soil microbial co‐occurrence networks scale positively with island area,indicating that habitat loss will potentially simplify and destabilize soil microbial networks.
