This paper discussed the keystone species concept and introduced the typical characteristics of keystone species and their identification in communities or ecosystems. Based on the research of the keystone species, th...This paper discussed the keystone species concept and introduced the typical characteristics of keystone species and their identification in communities or ecosystems. Based on the research of the keystone species, the concept of species importance (SI) was first advanced in this paper. The species importance can be simply understood as the important value of species in the ecosystem, which consists of three indexes: species structural important value (SIV), functional important value (FIV) and dynamical important value (DIV). With the indexes, the evaluation was also made on species importance of arbor trees in the Three-Hardwood forests (Fraxinus mandshurica, Juglans mandshurica, and Phellodendron amurense) ecosystem.展开更多
Metabolic interactions between microbiomes and algal hosts within the phycosphere of marine macroalgae are drawing increasing attention due to their roles in food webs,global nutrient cycles,industries,and their poten...Metabolic interactions between microbiomes and algal hosts within the phycosphere of marine macroalgae are drawing increasing attention due to their roles in food webs,global nutrient cycles,industries,and their potential as food resources.However,these relations remain poorly understood.In this study,43 marine macroalgae,including red,brown,and green algae,were collected from the coastal areas of Korea.We identified the bacterial communities within the loosely and tightly attached environments(LAEs and TAEs,respectively)of the phycosphere,along with those in the surrounding seawater,using 16S rRNA gene sequencing.β-Diversity analysis revealed significant differences between the bacterial communi-ties among the three,with minimal variation related to sampling location or algal color.Indicator value analysis identified Pseudoalteromonas(in the LAE and TAE),Psychromonas(in the LAE),Marinomonas(in the LAE),and Litorimonas(in the TAE)as the dominant taxa in the phycosphere,in contrast to seawater.Network analysis suggested positive correla-tions among taxa within the same environments and negative correlations between those in the LAE and TAE,highlighting their distinct ecological conditions.Analysis using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States and Kyoto Encyclopedia of Genes and Genomes pathways revealed functional variations between the phycosphere-and seawater-residing microbes.The microbial taxa-function relationships were assessed through Spearman’s rank-order correlation.Additionally,bacterial species belonging to the core taxa were isolated and their genomes sequenced.Their metabolic traits were analyzed via bioinformatics,recognizing key metabolic features essential for symbiotic inter-actions with algal hosts and survival within the phycosphere.The findings of this study advance our understanding of the marine algal phycosphere microbiome by detailing the metabolic characteristics of potential keystone species.展开更多
Precipitation significantly influences the composition and structure of grassland ecosystems,particularly in arid desert steppes.Stipa breviflora,as a keystone species,plays a crucial role in maintaining the stability...Precipitation significantly influences the composition and structure of grassland ecosystems,particularly in arid desert steppes.Stipa breviflora,as a keystone species,plays a crucial role in maintaining the stability of the desert steppe.However,the response of s.breviflora's succession strategy to changes in precipitation within the community remains uncertain.Since 2016,this research was conducted in a desert steppe in Inner Mongolia,China,involving control precipitation(PCK),and increases of 50%(P50)and 100%(P100)in natural precipitation.We measured biomass,height and canopy cover,calculated the importance value(IV)by species,and assessed the photosynthetic parameters and leaf elemental content of S.breviflora in 2021 and 2022.Results showed that the increase of precipitation significantly reduced the IV of S.breviflora.The net photosynthetic rate,transpiration rate,stomatal conductance,aboveground biomass carbon content and aboveground biomass nitrogen of S.breviflora leaves grew considerably in experimental plots receiving more precipitation,while S13C value of leaves decreased significantly.Linear regression analysis and structural equation model showed that although the increase of precipitation improved the adaptability of S.breviflora functional traits and increased its IV,a higher transpiration rate significantly contributed to the decrease in its IV.Consequently,our research reveals the succession strategy of S.breviflora and provides a theoretical basis for studying the response mechanisms of desert steppe plant communities to climate change.展开更多
As a new type of heritage,Agricultural Heritage Systems(AHS),represented by Globally Important Agricultural Heritage Systems(GIAHS)designated by Food and Agriculture Organization of the United Nations(FAO)and National...As a new type of heritage,Agricultural Heritage Systems(AHS),represented by Globally Important Agricultural Heritage Systems(GIAHS)designated by Food and Agriculture Organization of the United Nations(FAO)and Nationally Important Agricultural Heritage Systems(NIAHS)designated by some countries’Ministry of Agriculture,are typical Social-Ecological Systems(SES),which usually are rich in biodiversity,traditional knowledge,resource utilization technology and outstanding cultural landscapes.Cultural Keystone Species(CKS)are defined as the culturally salient species that shape the cultural identity of a people in a major way.CKS can be used as a prominent tool for the synergistic conservation of SES biology and culture,and to promote the overall enhancement of system functions.This paper summarizes a review of the definition of the CKS and its application in SES conservation.According to the characteristics and protection needs of AHS,this paper defined the CKS in AHS as:“Composites of biological resources and cultural practices,which have a significant impact on the stability of local society and culture systems,contribute to the achievement of AHS’conservation goals.”Based on this definition,we analyzed the significance of the identification of CKS in AHS.First of all,CKS help to quickly identify the key elements of AHS.Secondly,CKS can promote community participation in the conservation and development of AHS.In addition,the identification of CKS has a significant role in food and livelihood security,biodiversity conservation,traditional knowledge and technology transmission,social organization maintenance,and cultural landscape maintenance in AHS,which helps to achieve the conservation goals of GIAHS and/or NIAHS.展开更多
Rapid development and urbanization in recent years have contributed to a reduction in freshwater discharge and intensified saltwater intrusion in the Pearl River Delta. This comprises a significant threat to potable w...Rapid development and urbanization in recent years have contributed to a reduction in freshwater discharge and intensified saltwater intrusion in the Pearl River Delta. This comprises a significant threat to potable water supplies and overall estuary ecosystem health. In this study, the environmental flows of the Modaomen Estuary, one of the estuaries of the Pear/River Delta in China, were determined based on the salinity demand of keystone species and the linear relationship between river discharge and estuarine salinity. The estimated minimum and optimal annual environmental flows in the Modaomen Estuary were 116.8 ~ I09m3 and 273.8 ~ 109m3, respectively, representing 59.3% and 139.0% of the natural runoff. Water quality assessments in recent years indicate that the environmental flows have not been satisfied most of the time, particularly the optimal environmental flow, despite implementation of various water regulations since 2005. Therefore, water regulations and wetland network recov- eries based on rational environmental flows should be implemented to alleviate saltwater intrusion and for the creation of an ideal estuarine habitat.展开更多
In mutualistic interactions,all parties are usually considered to benefit;yet there may be asymmetries in mutualisms where some partners/individuals benefit more than others.Such is thought to be the case in mixedspec...In mutualistic interactions,all parties are usually considered to benefit;yet there may be asymmetries in mutualisms where some partners/individuals benefit more than others.Such is thought to be the case in mixedspecies flocks of birds,where following species are thought to benefit more than leading species,and leading species may not be able to escape the association if they are subordinate to other species.We measured dominance and affiliation patterns of a mixed-species flock system of southern China in an aviary where these variables could be measured in a standardized way.In eight wild-caught flocks,the leading species,David’s Fulvetta(Alcippe davidi),was usually among the more subordinate flock members(ranking 9 of 13 species,with the the most dominant species ranked number one,and dominance measured by normalized David’s scores).Dominance was strongly influenced by body mass,and not by bill length or the number of individuals.Female fulvettas in particular tended to be among the most subordinate individuals in the flock.There was evidence of a negative relationship between a species pair’s affiliation,measured as the percentage of all observations in which these two species were found perching together,and their difference in ranking in the dominance hierarchy,particularly when some ground species,which are not likely to remain in flocks long term,were removed from the analysis.Species pairs that had more pronounced differences in their dominance rankings were less likely to be affiliated,which is consistent with the idea that subordinate species may avoid dominants.David’s Fulvetta is a strong information provider,so other species are likely benefitted in this relationship.Our data suggest one reason that fulvettas stay in flocks is that they may be subordinate and therefore have little control over who associates with them.展开更多
Background:Mixed-species flocks(MSFs)have been well sampled in the South Asia,but there has been as yet surprisingly little work on MSFs of Nepal,despite a diverse and well-studied avifauna.We surveyed MSFs in two for...Background:Mixed-species flocks(MSFs)have been well sampled in the South Asia,but there has been as yet surprisingly little work on MSFs of Nepal,despite a diverse and well-studied avifauna.We surveyed MSFs in two forest types in and around the Important Bird Area of Chitwan National Park in Nepal,between 150 and 800 m a.s.l.,to provide a first description of the composition of MSFs in this area.We also aimed to understand which species should be considered‘nuclear species',important to forming MSFs or leading them forward.Results:In total,we collected records on 222 MSFs that included 100 species,and 6097 individuals.The MSFs were similar to worldwide patterns in being dominated by leaf-gleaning,non-terrestrial insectivores.However,the MSFs were more dominated by canopy species than usual,and did not have a clear gregarious,understory leading species.Rather drongos(Family Dicruridae)and minivets(Family Campephagidae,Genus Pericrocotus)acted as leaders,and a cluster analysis of composition showed one group of large body size MSFs particularly characterized by the presence of the Greater Racket-tailed Drongo(Dicrurus paradiseus).Conclusions:Drongos are known to provide both costs and benefits to other flock participants:they are aggressive birds that can steal food,and manipulate other species with their vocalizations,but at the same time they are‘sentinel species'that produce information about predation risk other species can use.This study demonstrates that drongos can be considered nuclear species for some types of MSFs,despite the potential costs of their presence.MSFs led by sentinel species thus may form in Asia,as well as in the Neotropics.展开更多
The present work has compiled a total of 389 brachyuran crab species belonging to 188 genera and 38 families to be present in mangrove forests across 122 countries/territories in 10 sub-regions of two global hemispher...The present work has compiled a total of 389 brachyuran crab species belonging to 188 genera and 38 families to be present in mangrove forests across 122 countries/territories in 10 sub-regions of two global hemispheres viz.,Indo-West Pacific(IWP)and Atlantic East Pacific(AEP).The mangrove crabs are highly diverse in the IWP as compared to AEP.They exceed 100 species in nine countries of the IWP viz.,Indonesia,India,Japan,Thailand,Australia,Singapore,Philippines,Malaysia,and China.The least number of mangrove crab species(>10)are found to be present in 38 countries under the AEP.Four countries/territories do not have any record of mangrove crabs.Sesarmidae is the predominant family of mangrove crabs,followed by Ocypodidae and Portunidae.The present work also has brought out 818 synonyms,which otherwise interfere with the preparation of a checklist for an exact number of crab species.It is a matter of necessity to conserve the crabs,which are keystone species of the mangrove ecosystems.展开更多
Worldwide,tropical montane cloud forest is one of the most important and biodiverse ecosystems;however,it is also one of those most threatened by anthropic activities.These activities lead to a fragmented,deforested l...Worldwide,tropical montane cloud forest is one of the most important and biodiverse ecosystems;however,it is also one of those most threatened by anthropic activities.These activities lead to a fragmented,deforested landscape with narrow riparian forest strips immersed in an agricultural matrix dominated by pastures.Here,we characterize the interaction network between frugivorous birds and zoochorous plants in riparian strips of cloud forest in deforested landscapes of Central Veracruz,Mexico.To characterize the network of this mutualistic interaction,we estimated network-and species-level metrics using the Bipartite R package.Nestedness,modularity and robustness were used to describe network structure.Centrality measures of degree,closeness,betweenness centrality and their relative contribution to nestedness were used to determine the importance of each bird/plant species to the network’s structure.This interaction network has 24 species of birds and 30 species of plants,with low connectance(0.11),low nestedness(11.53),and intermediate but not significant modularity(0.49).The bird species most important to network stability were Chlorospingus flavopectus,Myadestes occidentalis,and Catharus mexicanus.The most important plants were Conostegia xalapensis,C.arborea,and Rubus ulmifolius.Network robustness varied from 0.36 to 0.86 and its stability is compromised when species of birds or plants with the highest values of centrality are removed,with plant removal more detrimental.Riparian strips of cloud forest crossing deforested areas maintain a relatively rich set of birds that disperse the seeds of many forest plants,thus they are crucial to the preservation of this mutualistic network in anthropic landscapes.Network stability is severely undermined by the loss of any of the few species—whether birds or plants—with high centrality values.The most important plants for this stability are pioneer tree and shrub species that provide food for several bird species,and they are also crucial to cloud forest regeneration.A worrisome finding is that some of the bird species most important to network stability are also among the most sought-after as ornamental birds by illegal collectors in the region.展开更多
Although the contribution of biodiversity to supporting ecosystem functions is well established in soil ecosystems, previous studies have often overlooked the importance of potential multitrophic interactions in suppo...Although the contribution of biodiversity to supporting ecosystem functions is well established in soil ecosystems, previous studies have often overlooked the importance of potential multitrophic interactions in supporting ecosystem functions. This study analyzed the effects of land uses on potential multitrophic interactions and their impacts on soil ecosystem functions, using soil environmental DNA samples from five land-use types. Results showed that land use can influence soil ecosystem functions by altering the soil multitrophic biodiversity and interactions. Keystone species are crucial in shaping the soil microbial composition, mediating network interactions, and supporting the ecosystem function. This study promotes the understanding of the mechanisms behind changes in biodiversity and ecosystem services resulting from land-use changes and is beneficial to making informed trade-offs in urban planning.展开更多
The upward shift of the alpine treeline driven by global climate change has been extensively observed across many mountain ecosystems worldwide.However,variations in belowground microbial communities in the treeline e...The upward shift of the alpine treeline driven by global climate change has been extensively observed across many mountain ecosystems worldwide.However,variations in belowground microbial communities in the treeline ecotone,as well as the influence of microtopographic factors(e.g.,slope aspect)on these changes,remain unclear.Here,we collected soil samples from different aspects above or below the treeline and analyzed the microbial communities using high-throughput sequencing.Our study revealed distinct community characteristics,co-occurrence patterns,and assembly processes between bacterial and fungal communities.Especially,homogeneous selection and dispersal limitation played dominant roles in shaping bacterial and fungal communities,respectively.Keystone bacteria were more critical for maintaining network stability above the treeline,while fungi were the keystone taxa for network stability below the treeline.We also found that oligotrophic species such as Acidobacteriota,Chloroflexi,Verrucomicrobiota,and Ascomycota were predominantly enriched above the treeline,whereas copiotrophic species like Proteobacteria,Gemmatimonadota,Actinobacteriota,and Firmicutes were more abundant below the treeline.Our results uncovered that microbial communities responded greatly to treeline shift than slope aspect,and also imply that the upward shift of the alpine treeline may increase the stochasticity of microbial communities.These findings facilitate our understanding of how microbial communities in the treeline transition zones of alpine ecosystems respond to global warming and their potential effects on soil carbon dynamics.展开更多
Understanding a species’functional traits allows for a directed and productive perspective on the role a species plays in nature,and thus its relative importance to conservation planning.The functionaltrait ecology o...Understanding a species’functional traits allows for a directed and productive perspective on the role a species plays in nature,and thus its relative importance to conservation planning.The functionaltrait ecology of the plateau pika Ochotona curzoniae is examined to better understand the resilience and sustainability of the high alpine grasslands of the Qinghai-Tibetan Plateau(QTP).The key functional traits of plateau pikas are their abundance and behavior of digging extensive burrow systems.Plateau pikas have been poisoned over a significant part of their original geographic distribution across the QTP,allowing comparison of ecological communities with and without pikas.Nearly all mammalian and avian carnivores,most of which are obligate predators on pikas,have been lost in regions where pikas have been poisoned.Most endemic birds on the QTP nest in pika burrows;when pikas are poisoned,burrows collapse,and these birds are greatly reduced in number.Due to the biopedturbation resulting from their burrows,regional plant species richness is higher in areas with pikas than without.The presence of pika burrows allows higher rates of infiltration during heavy monsoon rains compared to poisoned areas,possibly mitigating runoff and the potential for serious downslope erosion and flooding.Thus,the functional traits of plateau pikas enhance native biodiversity and other important ecosystem functions;these traits are irreplaceable.As plateau pikas are not natural colonizers,active reintroduction programs are needed to restore pikas to areas from which they have been poisoned to restore the important functional ecological traits of pikas.展开更多
Rodents play an important role in rangelands through the engineering of extensive burrow systems,which provides key habitats for many animal and plant species.We have analyzed the long-term variation in the abun...Rodents play an important role in rangelands through the engineering of extensive burrow systems,which provides key habitats for many animal and plant species.We have analyzed the long-term variation in the abundance and distribution of rodent burrows in grazing ecosystems of southern Russia(Kalmykia)under the landscape change from desert to steppe caused by the drastic reduction of livestock after the collapse of the USSR in the early 1990s.We conducted burrow surveys in the“desert”(1980)and“steppe”(2017)periods on 193-km transects.We found considerable changes in burrow abundance and distribution,as well as evidence of desert habitat fragmentation and isolation caused by the expansion of tall-grass communities.Burrows of the open-dwelling diurnal ground squirrel(Spermophilus pygmaeus),the dominant and the keystone species during the“desert”period,almost completely disappeared from the rodent burrow network by 2017,indicating significant habitat loss.In contrast,the burrows of the folivorous social vole(Microtus socialis)which was rare in the 1980s,became abundant and ubiquitously distributed.The burrow density of the desert-dwelling psammophilous midday gerbil(Meriones meridianus)decreased,while the distances between occupied patches increased,indicating desert habitat fragmentation and loss of population connectivity.Burrows of the folivorous tamarisk gerbils(M.tamariscinus)were recorded only sporadically in both 1980 and 2017.The observed changes in the rodent burrow network,the key component of grazing ecosystems,correlate with rodent species ecology and can have long-term and important consequences for ecosystem functioning.展开更多
基金The paper was supported by science foundation of Changbai Mountain Open Research Station Chinese Academy of Sci-ences and Heilongjiang Natural Science Foundation (C00-01).
文摘This paper discussed the keystone species concept and introduced the typical characteristics of keystone species and their identification in communities or ecosystems. Based on the research of the keystone species, the concept of species importance (SI) was first advanced in this paper. The species importance can be simply understood as the important value of species in the ecosystem, which consists of three indexes: species structural important value (SIV), functional important value (FIV) and dynamical important value (DIV). With the indexes, the evaluation was also made on species importance of arbor trees in the Three-Hardwood forests (Fraxinus mandshurica, Juglans mandshurica, and Phellodendron amurense) ecosystem.
基金supported by grants from the Marine Biotics project(20210469)funded by the Ministry of Ocean and Fisheries,Republic of Korea.
文摘Metabolic interactions between microbiomes and algal hosts within the phycosphere of marine macroalgae are drawing increasing attention due to their roles in food webs,global nutrient cycles,industries,and their potential as food resources.However,these relations remain poorly understood.In this study,43 marine macroalgae,including red,brown,and green algae,were collected from the coastal areas of Korea.We identified the bacterial communities within the loosely and tightly attached environments(LAEs and TAEs,respectively)of the phycosphere,along with those in the surrounding seawater,using 16S rRNA gene sequencing.β-Diversity analysis revealed significant differences between the bacterial communi-ties among the three,with minimal variation related to sampling location or algal color.Indicator value analysis identified Pseudoalteromonas(in the LAE and TAE),Psychromonas(in the LAE),Marinomonas(in the LAE),and Litorimonas(in the TAE)as the dominant taxa in the phycosphere,in contrast to seawater.Network analysis suggested positive correla-tions among taxa within the same environments and negative correlations between those in the LAE and TAE,highlighting their distinct ecological conditions.Analysis using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States and Kyoto Encyclopedia of Genes and Genomes pathways revealed functional variations between the phycosphere-and seawater-residing microbes.The microbial taxa-function relationships were assessed through Spearman’s rank-order correlation.Additionally,bacterial species belonging to the core taxa were isolated and their genomes sequenced.Their metabolic traits were analyzed via bioinformatics,recognizing key metabolic features essential for symbiotic inter-actions with algal hosts and survival within the phycosphere.The findings of this study advance our understanding of the marine algal phycosphere microbiome by detailing the metabolic characteristics of potential keystone species.
基金supported by the National Natural Science Foundation ofChina(32460353,U23A2001,31560140)the Key Project of Science and Technology in Inner Mongolia of China(2021zD0044)the Interdisciplinary Fund Project of Inner Mongolia Agricultural University(BR22-14-04).
文摘Precipitation significantly influences the composition and structure of grassland ecosystems,particularly in arid desert steppes.Stipa breviflora,as a keystone species,plays a crucial role in maintaining the stability of the desert steppe.However,the response of s.breviflora's succession strategy to changes in precipitation within the community remains uncertain.Since 2016,this research was conducted in a desert steppe in Inner Mongolia,China,involving control precipitation(PCK),and increases of 50%(P50)and 100%(P100)in natural precipitation.We measured biomass,height and canopy cover,calculated the importance value(IV)by species,and assessed the photosynthetic parameters and leaf elemental content of S.breviflora in 2021 and 2022.Results showed that the increase of precipitation significantly reduced the IV of S.breviflora.The net photosynthetic rate,transpiration rate,stomatal conductance,aboveground biomass carbon content and aboveground biomass nitrogen of S.breviflora leaves grew considerably in experimental plots receiving more precipitation,while S13C value of leaves decreased significantly.Linear regression analysis and structural equation model showed that although the increase of precipitation improved the adaptability of S.breviflora functional traits and increased its IV,a higher transpiration rate significantly contributed to the decrease in its IV.Consequently,our research reveals the succession strategy of S.breviflora and provides a theoretical basis for studying the response mechanisms of desert steppe plant communities to climate change.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23100203)。
文摘As a new type of heritage,Agricultural Heritage Systems(AHS),represented by Globally Important Agricultural Heritage Systems(GIAHS)designated by Food and Agriculture Organization of the United Nations(FAO)and Nationally Important Agricultural Heritage Systems(NIAHS)designated by some countries’Ministry of Agriculture,are typical Social-Ecological Systems(SES),which usually are rich in biodiversity,traditional knowledge,resource utilization technology and outstanding cultural landscapes.Cultural Keystone Species(CKS)are defined as the culturally salient species that shape the cultural identity of a people in a major way.CKS can be used as a prominent tool for the synergistic conservation of SES biology and culture,and to promote the overall enhancement of system functions.This paper summarizes a review of the definition of the CKS and its application in SES conservation.According to the characteristics and protection needs of AHS,this paper defined the CKS in AHS as:“Composites of biological resources and cultural practices,which have a significant impact on the stability of local society and culture systems,contribute to the achievement of AHS’conservation goals.”Based on this definition,we analyzed the significance of the identification of CKS in AHS.First of all,CKS help to quickly identify the key elements of AHS.Secondly,CKS can promote community participation in the conservation and development of AHS.In addition,the identification of CKS has a significant role in food and livelihood security,biodiversity conservation,traditional knowledge and technology transmission,social organization maintenance,and cultural landscape maintenance in AHS,which helps to achieve the conservation goals of GIAHS and/or NIAHS.
文摘Rapid development and urbanization in recent years have contributed to a reduction in freshwater discharge and intensified saltwater intrusion in the Pearl River Delta. This comprises a significant threat to potable water supplies and overall estuary ecosystem health. In this study, the environmental flows of the Modaomen Estuary, one of the estuaries of the Pear/River Delta in China, were determined based on the salinity demand of keystone species and the linear relationship between river discharge and estuarine salinity. The estimated minimum and optimal annual environmental flows in the Modaomen Estuary were 116.8 ~ I09m3 and 273.8 ~ 109m3, respectively, representing 59.3% and 139.0% of the natural runoff. Water quality assessments in recent years indicate that the environmental flows have not been satisfied most of the time, particularly the optimal environmental flow, despite implementation of various water regulations since 2005. Therefore, water regulations and wetland network recov- eries based on rational environmental flows should be implemented to alleviate saltwater intrusion and for the creation of an ideal estuarine habitat.
基金supported by the National Science Foundation of China,grant 31770424a Special Talents Recruitment Grant from Guangxi University.
文摘In mutualistic interactions,all parties are usually considered to benefit;yet there may be asymmetries in mutualisms where some partners/individuals benefit more than others.Such is thought to be the case in mixedspecies flocks of birds,where following species are thought to benefit more than leading species,and leading species may not be able to escape the association if they are subordinate to other species.We measured dominance and affiliation patterns of a mixed-species flock system of southern China in an aviary where these variables could be measured in a standardized way.In eight wild-caught flocks,the leading species,David’s Fulvetta(Alcippe davidi),was usually among the more subordinate flock members(ranking 9 of 13 species,with the the most dominant species ranked number one,and dominance measured by normalized David’s scores).Dominance was strongly influenced by body mass,and not by bill length or the number of individuals.Female fulvettas in particular tended to be among the most subordinate individuals in the flock.There was evidence of a negative relationship between a species pair’s affiliation,measured as the percentage of all observations in which these two species were found perching together,and their difference in ranking in the dominance hierarchy,particularly when some ground species,which are not likely to remain in flocks long term,were removed from the analysis.Species pairs that had more pronounced differences in their dominance rankings were less likely to be affiliated,which is consistent with the idea that subordinate species may avoid dominants.David’s Fulvetta is a strong information provider,so other species are likely benefitted in this relationship.Our data suggest one reason that fulvettas stay in flocks is that they may be subordinate and therefore have little control over who associates with them.
基金supported by a Special Talent Recruitment grant from Guangxi University to EGa Chinese Government Scholarship to KRG。
文摘Background:Mixed-species flocks(MSFs)have been well sampled in the South Asia,but there has been as yet surprisingly little work on MSFs of Nepal,despite a diverse and well-studied avifauna.We surveyed MSFs in two forest types in and around the Important Bird Area of Chitwan National Park in Nepal,between 150 and 800 m a.s.l.,to provide a first description of the composition of MSFs in this area.We also aimed to understand which species should be considered‘nuclear species',important to forming MSFs or leading them forward.Results:In total,we collected records on 222 MSFs that included 100 species,and 6097 individuals.The MSFs were similar to worldwide patterns in being dominated by leaf-gleaning,non-terrestrial insectivores.However,the MSFs were more dominated by canopy species than usual,and did not have a clear gregarious,understory leading species.Rather drongos(Family Dicruridae)and minivets(Family Campephagidae,Genus Pericrocotus)acted as leaders,and a cluster analysis of composition showed one group of large body size MSFs particularly characterized by the presence of the Greater Racket-tailed Drongo(Dicrurus paradiseus).Conclusions:Drongos are known to provide both costs and benefits to other flock participants:they are aggressive birds that can steal food,and manipulate other species with their vocalizations,but at the same time they are‘sentinel species'that produce information about predation risk other species can use.This study demonstrates that drongos can be considered nuclear species for some types of MSFs,despite the potential costs of their presence.MSFs led by sentinel species thus may form in Asia,as well as in the Neotropics.
基金DST-TWAS for Post-Doc.Fellowship(WWM,FR No.3240306336).
文摘The present work has compiled a total of 389 brachyuran crab species belonging to 188 genera and 38 families to be present in mangrove forests across 122 countries/territories in 10 sub-regions of two global hemispheres viz.,Indo-West Pacific(IWP)and Atlantic East Pacific(AEP).The mangrove crabs are highly diverse in the IWP as compared to AEP.They exceed 100 species in nine countries of the IWP viz.,Indonesia,India,Japan,Thailand,Australia,Singapore,Philippines,Malaysia,and China.The least number of mangrove crab species(>10)are found to be present in 38 countries under the AEP.Four countries/territories do not have any record of mangrove crabs.Sesarmidae is the predominant family of mangrove crabs,followed by Ocypodidae and Portunidae.The present work also has brought out 818 synonyms,which otherwise interfere with the preparation of a checklist for an exact number of crab species.It is a matter of necessity to conserve the crabs,which are keystone species of the mangrove ecosystems.
基金The Rufford Foundation(Our ref:20471–1)the Consejo Nacional de Ciencia y Tecnología(grants CB-2008-01 No.101542,CB-2016-01 No.285962)for funding。
文摘Worldwide,tropical montane cloud forest is one of the most important and biodiverse ecosystems;however,it is also one of those most threatened by anthropic activities.These activities lead to a fragmented,deforested landscape with narrow riparian forest strips immersed in an agricultural matrix dominated by pastures.Here,we characterize the interaction network between frugivorous birds and zoochorous plants in riparian strips of cloud forest in deforested landscapes of Central Veracruz,Mexico.To characterize the network of this mutualistic interaction,we estimated network-and species-level metrics using the Bipartite R package.Nestedness,modularity and robustness were used to describe network structure.Centrality measures of degree,closeness,betweenness centrality and their relative contribution to nestedness were used to determine the importance of each bird/plant species to the network’s structure.This interaction network has 24 species of birds and 30 species of plants,with low connectance(0.11),low nestedness(11.53),and intermediate but not significant modularity(0.49).The bird species most important to network stability were Chlorospingus flavopectus,Myadestes occidentalis,and Catharus mexicanus.The most important plants were Conostegia xalapensis,C.arborea,and Rubus ulmifolius.Network robustness varied from 0.36 to 0.86 and its stability is compromised when species of birds or plants with the highest values of centrality are removed,with plant removal more detrimental.Riparian strips of cloud forest crossing deforested areas maintain a relatively rich set of birds that disperse the seeds of many forest plants,thus they are crucial to the preservation of this mutualistic network in anthropic landscapes.Network stability is severely undermined by the loss of any of the few species—whether birds or plants—with high centrality values.The most important plants for this stability are pioneer tree and shrub species that provide food for several bird species,and they are also crucial to cloud forest regeneration.A worrisome finding is that some of the bird species most important to network stability are also among the most sought-after as ornamental birds by illegal collectors in the region.
基金supported by the National Natural Science Foundation of China(Grant Nos.32361143523,42307033,and 42222701)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2023321)+1 种基金Ningbo Yongjiang Talent Project(Grant No.2022A-163-G)Ningbo S&T Project(Grant No.2021-DST-004).
文摘Although the contribution of biodiversity to supporting ecosystem functions is well established in soil ecosystems, previous studies have often overlooked the importance of potential multitrophic interactions in supporting ecosystem functions. This study analyzed the effects of land uses on potential multitrophic interactions and their impacts on soil ecosystem functions, using soil environmental DNA samples from five land-use types. Results showed that land use can influence soil ecosystem functions by altering the soil multitrophic biodiversity and interactions. Keystone species are crucial in shaping the soil microbial composition, mediating network interactions, and supporting the ecosystem function. This study promotes the understanding of the mechanisms behind changes in biodiversity and ecosystem services resulting from land-use changes and is beneficial to making informed trade-offs in urban planning.
基金supported by the National Natural Science Foundation of China(Grant Nos.42177274,42377119)the Second Tibetan Plateau Scientific Expedition and Research Program(Grant Nos.2019QZKK0308,2019QZKK0306).
文摘The upward shift of the alpine treeline driven by global climate change has been extensively observed across many mountain ecosystems worldwide.However,variations in belowground microbial communities in the treeline ecotone,as well as the influence of microtopographic factors(e.g.,slope aspect)on these changes,remain unclear.Here,we collected soil samples from different aspects above or below the treeline and analyzed the microbial communities using high-throughput sequencing.Our study revealed distinct community characteristics,co-occurrence patterns,and assembly processes between bacterial and fungal communities.Especially,homogeneous selection and dispersal limitation played dominant roles in shaping bacterial and fungal communities,respectively.Keystone bacteria were more critical for maintaining network stability above the treeline,while fungi were the keystone taxa for network stability below the treeline.We also found that oligotrophic species such as Acidobacteriota,Chloroflexi,Verrucomicrobiota,and Ascomycota were predominantly enriched above the treeline,whereas copiotrophic species like Proteobacteria,Gemmatimonadota,Actinobacteriota,and Firmicutes were more abundant below the treeline.Our results uncovered that microbial communities responded greatly to treeline shift than slope aspect,and also imply that the upward shift of the alpine treeline may increase the stochasticity of microbial communities.These findings facilitate our understanding of how microbial communities in the treeline transition zones of alpine ecosystems respond to global warming and their potential effects on soil carbon dynamics.
基金the following sources over the years:National Science Foundation(INT-8920440,INT-9016551,INT-9249613,Dynamics of Coupled Natural and Human Systems Pro-gram-0815441Pre-doctoral Fellowship Program)+11 种基金National Geographic SocietyNational Academy of Sci-ences(Henry Fund)Earthwatch-the Center for Field StudiesKadoorie Charitable Foundation(Hong Kong)Biodiversity Working Group-China Council for Interna-tional Cooperation in Environment and DevelopmentUnited Board for Christian Higher EducationKeidanren Nature Conservation Fund,JapanPhoenix Zoo Conservation and Science Grants ProgramCleveland Metroparks Zoo Asia Seed FundProject 111-PRC Min-istry of EducationNational Security Education Program-David L.Boren FellowshipArizona State University(School of Life Sciences,Center for Asian Studies,College of Liberal Arts and Sciences,Graduate Col-lege).Sharon Hall kindly supplied information on the unique soil properties found on the QTP.We are grate-ful to Aryn Musgrave for drafting the range map of the plateau pika.We thank Harriet Smith for her insightful comments on an earlier draft of the manuscript.
文摘Understanding a species’functional traits allows for a directed and productive perspective on the role a species plays in nature,and thus its relative importance to conservation planning.The functionaltrait ecology of the plateau pika Ochotona curzoniae is examined to better understand the resilience and sustainability of the high alpine grasslands of the Qinghai-Tibetan Plateau(QTP).The key functional traits of plateau pikas are their abundance and behavior of digging extensive burrow systems.Plateau pikas have been poisoned over a significant part of their original geographic distribution across the QTP,allowing comparison of ecological communities with and without pikas.Nearly all mammalian and avian carnivores,most of which are obligate predators on pikas,have been lost in regions where pikas have been poisoned.Most endemic birds on the QTP nest in pika burrows;when pikas are poisoned,burrows collapse,and these birds are greatly reduced in number.Due to the biopedturbation resulting from their burrows,regional plant species richness is higher in areas with pikas than without.The presence of pika burrows allows higher rates of infiltration during heavy monsoon rains compared to poisoned areas,possibly mitigating runoff and the potential for serious downslope erosion and flooding.Thus,the functional traits of plateau pikas enhance native biodiversity and other important ecosystem functions;these traits are irreplaceable.As plateau pikas are not natural colonizers,active reintroduction programs are needed to restore pikas to areas from which they have been poisoned to restore the important functional ecological traits of pikas.
基金the Russian Foundation for Basic Research(grants 16-04-00739 for AT and 18-34-00155 for ES).
文摘Rodents play an important role in rangelands through the engineering of extensive burrow systems,which provides key habitats for many animal and plant species.We have analyzed the long-term variation in the abundance and distribution of rodent burrows in grazing ecosystems of southern Russia(Kalmykia)under the landscape change from desert to steppe caused by the drastic reduction of livestock after the collapse of the USSR in the early 1990s.We conducted burrow surveys in the“desert”(1980)and“steppe”(2017)periods on 193-km transects.We found considerable changes in burrow abundance and distribution,as well as evidence of desert habitat fragmentation and isolation caused by the expansion of tall-grass communities.Burrows of the open-dwelling diurnal ground squirrel(Spermophilus pygmaeus),the dominant and the keystone species during the“desert”period,almost completely disappeared from the rodent burrow network by 2017,indicating significant habitat loss.In contrast,the burrows of the folivorous social vole(Microtus socialis)which was rare in the 1980s,became abundant and ubiquitously distributed.The burrow density of the desert-dwelling psammophilous midday gerbil(Meriones meridianus)decreased,while the distances between occupied patches increased,indicating desert habitat fragmentation and loss of population connectivity.Burrows of the folivorous tamarisk gerbils(M.tamariscinus)were recorded only sporadically in both 1980 and 2017.The observed changes in the rodent burrow network,the key component of grazing ecosystems,correlate with rodent species ecology and can have long-term and important consequences for ecosystem functioning.
