Soil samples were collected with distance at 5, 20, 40, 80, 160, and 320 m from the Shen-Ha （Shenyang-Harbin） Highway, Northeast China, to investigate the effect of heavy metals of highway origin on soil nematode gu...Soil samples were collected with distance at 5, 20, 40, 80, 160, and 320 m from the Shen-Ha （Shenyang-Harbin） Highway, Northeast China, to investigate the effect of heavy metals of highway origin on soil nematode guilds. The contents of soil Pb, Cu, Zn, and the nematode community structure were analyzed. The results showed that the contents of total and available Pb, Ca, Zn varied significantly with the different distances from the highway. Pb was the main pollutant in the soils in the vicinity of Shen-Ha Highway. The zone from 20 to 40 m away from the highway was the most polluted area. The highest abundance of soil nematodes was found at 5 m while the lowest at 20 m away from the highway. Thirty six genera of nematodes belonging to 23 families were identified. Nematode guilds having different responses to soil heavy metals were classified into four types. Soil nematode guilds may act as a prominent indicator to heavy metal pollution of highway origin.展开更多
The Naf River estuary is one of the most productive ecological ecosystems in Bangladesh providing an important feeding area for fishes and other aquatic animals.However,detailed information on macrobenthic communities...The Naf River estuary is one of the most productive ecological ecosystems in Bangladesh providing an important feeding area for fishes and other aquatic animals.However,detailed information on macrobenthic communities is rarely available in this area.Our study focused on the seasonal and spatial variability of macrobenthic community structure with their biomass and functional guilds.In total,fortyseven taxa were identified under nine major groups and seven functional feeding guilds.Among macrobenthic taxa,Polychaeta was dominant in both seasons and all over the estuary contributing 60%of total benthos.The mean abundance of macrobenthos was higher during the pre-monsoon(2 972±1 994 inds./m^2)than the monsoon(1 572±361 inds./m^2)being maximum at mid-estuary region and minimum at upper and lower estuary regions.Of the diversity indices,density(P=0.01,P=0.003),the number of taxa(P=0.000 3,P=0.000 9)and Margalef′s Index(P=0.000 4,P=0.001)of macrobenthos were significantly different among stations and seasons.Shannon-Weiner index(P=0.009,P=0.12)and Pielou’s evenness index(P=0.03,P=0.14)had significant differences among stations but not among seasons.Cluster analysis suggested that distribution of macrofauna is strongly influenced by seasonality.Among the feeding types,carnivorous were found to be dominant at the upper and mid-estuarine regions,and herbivorous were at lower estuarine regions.Carnivorous species were dominant in both seasons.Omnivores have shown to be the most abundant feeding type in terms of biomass though herbivores were highest during monsoon.展开更多
Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other i...Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or understudied.Methods: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), China.Results: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy guilds.Conclusions: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems.展开更多
Niche theory predicts that closely related and ecologically similar species with overlapping distribution ranges can coexist through resource partitioning that limits interspecific competition.However,studies examinin...Niche theory predicts that closely related and ecologically similar species with overlapping distribution ranges can coexist through resource partitioning that limits interspecific competition.However,studies examining the mechanisms promoting coexistence of top predators at a large geographical scale are still scant.Here,we describe the foraging ecology of 3 sympatric owl species(Northern long-eared owl[Asio otus],Tawny owl[Strix aluco],Eurasian eagle owl[Bubo bubo])in the Mediterranean Basin.We review 160 studies reporting diet information(212,236 vertebrate preys)and investigate among-species differences in diet metrics(diversity,evenness,prey size,and proportion of mammals)and their variation along geographical and environmental gradients.Moreover,we test whether diet metrics differ in presence or absence of the other predators.All the 3 species mainly rely on small mammals,but they significantly differ in diet metrics.The smallest predator(i.e.,long-eared owl)shows a higher level of specialism on small mammals(highest proportion but lowest diversity of mammals in the diet)compared to the larger ones.In addition,mean prey size significantly increases with predator body size(long-eared owl<tawny owl<eagle owl).Finally,interspecific competition results in an increase of diet diversity and evenness in the long-eared owl,and species’diet also varies in response to environmental factors.The 3 species thus segregate along several dietary niche axes over a large spatial scale and according to both morphological characteristics(i.e.,body size)and environmental variables.Such dietary niche segregation may adaptively buffer interspecific competition costs,ultimately allowing coexistence.展开更多
Anthropogenic activities are triggering planetary-scale transformations at an unprecedented rate,leading to profound impacts on biodiversity and ecosystem stability(Williams et al.2020;Ellis et al.2021).Human encroach...Anthropogenic activities are triggering planetary-scale transformations at an unprecedented rate,leading to profound impacts on biodiversity and ecosystem stability(Williams et al.2020;Ellis et al.2021).Human encroachment and the reduction of natural habitats are projected to imperil approximately 1700 terrestrial vertebrate species by 2070(Powers and Jetz 2019).These changes not only directly impact the persistence of individual species but also reshape community structures and ecosystem functions by altering intra-and interspecific interactions(Sévêque et al.2020;O’Connor et al.2024).展开更多
Background:Habitat heterogeneity clearly distinguished in terms of availability of food and habitat resources and landscape features(natural or human-modified)play a crucial role in the avian species composition and p...Background:Habitat heterogeneity clearly distinguished in terms of availability of food and habitat resources and landscape features(natural or human-modified)play a crucial role in the avian species composition and population structure.To examine this,a study was carried out in Bhubaneswar,India,to understand the ecological niche distinction in birds based on habitat heterogeneity.Regular sampling was conducted in 30 sampling sites covering six different habitat types in a predominantly urban landscape of Bhubaneswar for understanding the ecological niche in birds.The birds were classified into 11 types of foraging guilds.Results:The insectivorous guild had the highest bird species richness(181 species)and the omnivorous guild had the lowest(11 species).The piscivorous guild and wetland habitat had the strongest linkage,followed by the insectivorous guild and agricultural land.The frugivorous guild was significantly correlated with forest habitats(r=0.386,p<0.01)and park and garden habitats(r=0.281,p<0.01).This urban area hosted a higher number of bird species in certain habitat types,viz.,agricultural lands(52%,115 species)and forest patches(50%,111 species).Conclusion:The present study highlights the importance of agricultural lands,forest patches,parks and gardens,and wetlands inside the cityscape for supporting avifauna.It is therefore suggested that such habitats should be conserved inside an urban area to protect native avifauna.Thus,the city development plan must invariably include strategies for conserving the forest patches inside the urban area.Measures must be taken to restrain the degradation of agricultural lands and reduce their utilization for non-agricultural purposes,which will help in further reducing the bird population decline in the urban landscape.展开更多
Land-use sprawl in the Himalayas has caused the conversion of natural habitat into human-modified habitats,thus degrading ecosystem health.Adaptation of birds to changing physical environment can be well understood by...Land-use sprawl in the Himalayas has caused the conversion of natural habitat into human-modified habitats,thus degrading ecosystem health.Adaptation of birds to changing physical environment can be well understood by analyzing their habitat preferences,and foraging dynamics explored to a limited extent in the Himalayan region,as yet.To achieve a comprehensive understanding of avian guild structure,we used multivariate statistical techniques to classify bird species according to their similarities in foraging patterns and habitat preferences.Observations based on habitat and diet affinities accounted for rich avian diversity with a total of 208 bird species(about 15%of country’s avifauna)recorded from six different sites during 1 year survey.Unweighted pair-group average cluster analysis performed on the families revealed ten feeding and fifteen habitat guilds among 63 bird families observed.Subtropical forests harbored more species followed by urban forests and agricultural landscapes.Insectivorous and omnivorous outnumbered other feeding guilds in the study area.Bird assemblages were richer in protected areas and semidisturbed landscapes and did not show significant variation between the seasons.Results of the study revealed that different functional groups of birds behaved differently,primarily induced by choice of food.The site heterogeneity favored avifaunal persistence by providing favorable foraging,roosting,and nesting opportunities to birds.Composition of avian guilds indicated level of intactness and ecological integrity of ecosystems studied.This outcome thus sets the background for long-term analysis of bird-habitat relationship and their foraging dynamics.The study has the relevance for decision-makers to integrate avian guild structure as an essential ingredient in formulating conservation strategies.展开更多
This paper attempts to investigate the decline of Chinese guilds in the early 1950s and to show how political change altered economic life in China. Although the socialist transformation of private ownership started i...This paper attempts to investigate the decline of Chinese guilds in the early 1950s and to show how political change altered economic life in China. Although the socialist transformation of private ownership started in 1954, the new government used state power to gradually weaken private ownership far before that time, building a foundation for the full-scale socialist transformation later. The reorganization of the Teahouse Guild in Chengdu reflected the general policies of the Communist Party that changed traditional social and economic organizations. The new guild almost became a representative of the government in the teahouse profession, which no longer maintained the nature of the traditional guilds. Actually, the guilds existed in name only after the reorganization of the early 1950s, and the teahouse guild disappeared after 1953. The death of the guild was a result of decline among social organizations and the growing strength of state power.展开更多
基金supported by the National NaturalScience Foundation of China (No. 30600087)the Scientific Research Startup Special Foundation on Excellent Ph.D Thesis and Presidential Award of Chinese Academyof Sciences (No. 2007356).
文摘Soil samples were collected with distance at 5, 20, 40, 80, 160, and 320 m from the Shen-Ha （Shenyang-Harbin） Highway, Northeast China, to investigate the effect of heavy metals of highway origin on soil nematode guilds. The contents of soil Pb, Cu, Zn, and the nematode community structure were analyzed. The results showed that the contents of total and available Pb, Ca, Zn varied significantly with the different distances from the highway. Pb was the main pollutant in the soils in the vicinity of Shen-Ha Highway. The zone from 20 to 40 m away from the highway was the most polluted area. The highest abundance of soil nematodes was found at 5 m while the lowest at 20 m away from the highway. Thirty six genera of nematodes belonging to 23 families were identified. Nematode guilds having different responses to soil heavy metals were classified into four types. Soil nematode guilds may act as a prominent indicator to heavy metal pollution of highway origin.
文摘The Naf River estuary is one of the most productive ecological ecosystems in Bangladesh providing an important feeding area for fishes and other aquatic animals.However,detailed information on macrobenthic communities is rarely available in this area.Our study focused on the seasonal and spatial variability of macrobenthic community structure with their biomass and functional guilds.In total,fortyseven taxa were identified under nine major groups and seven functional feeding guilds.Among macrobenthic taxa,Polychaeta was dominant in both seasons and all over the estuary contributing 60%of total benthos.The mean abundance of macrobenthos was higher during the pre-monsoon(2 972±1 994 inds./m^2)than the monsoon(1 572±361 inds./m^2)being maximum at mid-estuary region and minimum at upper and lower estuary regions.Of the diversity indices,density(P=0.01,P=0.003),the number of taxa(P=0.000 3,P=0.000 9)and Margalef′s Index(P=0.000 4,P=0.001)of macrobenthos were significantly different among stations and seasons.Shannon-Weiner index(P=0.009,P=0.12)and Pielou’s evenness index(P=0.03,P=0.14)had significant differences among stations but not among seasons.Cluster analysis suggested that distribution of macrofauna is strongly influenced by seasonality.Among the feeding types,carnivorous were found to be dominant at the upper and mid-estuarine regions,and herbivorous were at lower estuarine regions.Carnivorous species were dominant in both seasons.Omnivores have shown to be the most abundant feeding type in terms of biomass though herbivores were highest during monsoon.
基金supported by the National Natural Science Foundation of China (No. 31170397)the Fundamental Research Funds for the Central Universities
文摘Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or understudied.Methods: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), China.Results: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy guilds.Conclusions: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems.
文摘Niche theory predicts that closely related and ecologically similar species with overlapping distribution ranges can coexist through resource partitioning that limits interspecific competition.However,studies examining the mechanisms promoting coexistence of top predators at a large geographical scale are still scant.Here,we describe the foraging ecology of 3 sympatric owl species(Northern long-eared owl[Asio otus],Tawny owl[Strix aluco],Eurasian eagle owl[Bubo bubo])in the Mediterranean Basin.We review 160 studies reporting diet information(212,236 vertebrate preys)and investigate among-species differences in diet metrics(diversity,evenness,prey size,and proportion of mammals)and their variation along geographical and environmental gradients.Moreover,we test whether diet metrics differ in presence or absence of the other predators.All the 3 species mainly rely on small mammals,but they significantly differ in diet metrics.The smallest predator(i.e.,long-eared owl)shows a higher level of specialism on small mammals(highest proportion but lowest diversity of mammals in the diet)compared to the larger ones.In addition,mean prey size significantly increases with predator body size(long-eared owl<tawny owl<eagle owl).Finally,interspecific competition results in an increase of diet diversity and evenness in the long-eared owl,and species’diet also varies in response to environmental factors.The 3 species thus segregate along several dietary niche axes over a large spatial scale and according to both morphological characteristics(i.e.,body size)and environmental variables.Such dietary niche segregation may adaptively buffer interspecific competition costs,ultimately allowing coexistence.
基金supported by the National Natural Science Foundation of China(32271737 and 32071544)the Interdisciplinary Innovation Team of the Chinese Academy of Sciences(CAS)“Light of West China”Program(xbzg-zdsys-202207).
文摘Anthropogenic activities are triggering planetary-scale transformations at an unprecedented rate,leading to profound impacts on biodiversity and ecosystem stability(Williams et al.2020;Ellis et al.2021).Human encroachment and the reduction of natural habitats are projected to imperil approximately 1700 terrestrial vertebrate species by 2070(Powers and Jetz 2019).These changes not only directly impact the persistence of individual species but also reshape community structures and ecosystem functions by altering intra-and interspecific interactions(Sévêque et al.2020;O’Connor et al.2024).
文摘Background:Habitat heterogeneity clearly distinguished in terms of availability of food and habitat resources and landscape features(natural or human-modified)play a crucial role in the avian species composition and population structure.To examine this,a study was carried out in Bhubaneswar,India,to understand the ecological niche distinction in birds based on habitat heterogeneity.Regular sampling was conducted in 30 sampling sites covering six different habitat types in a predominantly urban landscape of Bhubaneswar for understanding the ecological niche in birds.The birds were classified into 11 types of foraging guilds.Results:The insectivorous guild had the highest bird species richness(181 species)and the omnivorous guild had the lowest(11 species).The piscivorous guild and wetland habitat had the strongest linkage,followed by the insectivorous guild and agricultural land.The frugivorous guild was significantly correlated with forest habitats(r=0.386,p<0.01)and park and garden habitats(r=0.281,p<0.01).This urban area hosted a higher number of bird species in certain habitat types,viz.,agricultural lands(52%,115 species)and forest patches(50%,111 species).Conclusion:The present study highlights the importance of agricultural lands,forest patches,parks and gardens,and wetlands inside the cityscape for supporting avifauna.It is therefore suggested that such habitats should be conserved inside an urban area to protect native avifauna.Thus,the city development plan must invariably include strategies for conserving the forest patches inside the urban area.Measures must be taken to restrain the degradation of agricultural lands and reduce their utilization for non-agricultural purposes,which will help in further reducing the bird population decline in the urban landscape.
文摘Land-use sprawl in the Himalayas has caused the conversion of natural habitat into human-modified habitats,thus degrading ecosystem health.Adaptation of birds to changing physical environment can be well understood by analyzing their habitat preferences,and foraging dynamics explored to a limited extent in the Himalayan region,as yet.To achieve a comprehensive understanding of avian guild structure,we used multivariate statistical techniques to classify bird species according to their similarities in foraging patterns and habitat preferences.Observations based on habitat and diet affinities accounted for rich avian diversity with a total of 208 bird species(about 15%of country’s avifauna)recorded from six different sites during 1 year survey.Unweighted pair-group average cluster analysis performed on the families revealed ten feeding and fifteen habitat guilds among 63 bird families observed.Subtropical forests harbored more species followed by urban forests and agricultural landscapes.Insectivorous and omnivorous outnumbered other feeding guilds in the study area.Bird assemblages were richer in protected areas and semidisturbed landscapes and did not show significant variation between the seasons.Results of the study revealed that different functional groups of birds behaved differently,primarily induced by choice of food.The site heterogeneity favored avifaunal persistence by providing favorable foraging,roosting,and nesting opportunities to birds.Composition of avian guilds indicated level of intactness and ecological integrity of ecosystems studied.This outcome thus sets the background for long-term analysis of bird-habitat relationship and their foraging dynamics.The study has the relevance for decision-makers to integrate avian guild structure as an essential ingredient in formulating conservation strategies.
文摘This paper attempts to investigate the decline of Chinese guilds in the early 1950s and to show how political change altered economic life in China. Although the socialist transformation of private ownership started in 1954, the new government used state power to gradually weaken private ownership far before that time, building a foundation for the full-scale socialist transformation later. The reorganization of the Teahouse Guild in Chengdu reflected the general policies of the Communist Party that changed traditional social and economic organizations. The new guild almost became a representative of the government in the teahouse profession, which no longer maintained the nature of the traditional guilds. Actually, the guilds existed in name only after the reorganization of the early 1950s, and the teahouse guild disappeared after 1953. The death of the guild was a result of decline among social organizations and the growing strength of state power.
