Plant diversity plays a crucial role in maintaining the stability of ecological function.Based on field investigations and experimental analyses,artificial grassland plots with varying sowing times,adjacent natural gr...Plant diversity plays a crucial role in maintaining the stability of ecological function.Based on field investigations and experimental analyses,artificial grassland plots with varying sowing times,adjacent natural grassland(CK),and open-pit coal mine dumps in the Muli mining area of Qinghai Province were selected as research subjects for this study.The characteristics of plant diversity and community stability were measured and analyzed,and the relationships between these factors and their influencing variables were evaluated.The results indicated significant differences in the vegetation community characteristics and plant diversity among the various grasslands.Coverage,aboveground biomass,belowground biomass,soil total nitrogen,and soil total carbon were the highest when the growth period was three years.Plant diversity and community stability in the natural grassland were significantly greater than that in the artificial grassland and open-pit coal mine dumps.A significant positive correlation was observed between plant diversity and community stability,suggesting that plant diversity can serve as an index of community stability.The order of stability,from highest to lowest,was CK>11a>10a>8a>9a>6a>7a>3a>2a>1a>0a.Years were identified as the primary factors affecting plant diversity and community stability by altering the soil pH.These results elucidate the relationships and driving mechanisms between plant diversity and community stability in grasslands,providing a scientific basis for maintaining community stability in artificial grassland ecosystems in alpine mining areas.展开更多
Relationship between biodiversity and ecosystem function is one of the core issues in ecological research.Phytoplankton,as the main producer of aquatic ecosystem,its diversity,productivity,and community stability are ...Relationship between biodiversity and ecosystem function is one of the core issues in ecological research.Phytoplankton,as the main producer of aquatic ecosystem,its diversity,productivity,and community stability are of great signifi cance to reveal ecosystem function.There are signifi cant diff erences in hydrodynamics,water retention time,and phytoplankton community structure between river-type reservoir and newly built lake-type reservoir.The comparative analysis of phytoplankton community stability between the two types of reservoir has not been reported.Jiuquwan Reservoir(river-type)and Taihu Reservoir(lake-type),the two reservoirs in the Dongjiang River source area of Zhujiang(Pearl)River Basin,were selected for comparison in terms of multi-year operation vs.new impoundment,river-type vs.lake-type,and shallow water vs.sub-deep water reservoirs.Samples were collected in dry season(December 2019),normal season(March 2020),and wet season(August 2020),on which the phytoplankton diversity and productivity of the two reservoirs,and the relationship and diff erence of community stability were examined.Results show that(1)the number of phytoplankton species in Jiuquwan Reservoir decreased comparing that before algal bloom and the restoration treatment,while that in Taihu Reservoir increased compared with that before the impoundment of the reservoir.There was no signifi cant diff erence in functional groups and species number between the two reservoirs(P>0.05);(2)the biological stability,diversity,productivity,and resource utilization effi ciency of newly built lake-type reservoir were higher than those of multi-year river-type reservoir.In addition,the utilization effi ciency of phytoplankton resources was the highest in wet season in both reservoirs.The increases in biodiversity,richness,and evenness promoted the stability of the community,while increases in productivity and resource utilization effi ciency weakened the stability of the community;(3)community stability was aff ected by both biotic and abiotic factors,and hydrodynamic index was the main factor.This study is helpful to understand the relationship and diff erences in phytoplankton diversity,productivity and community stability in diff erent types of reservoirs,and provides a guidance for maintaining the stability of reservoir water ecosystem and protecting the biodiversity.The relationships between phytoplankton diversity,productivity,and community stability will be investigated in depth,for which a long-term observation will be conducted on the impact of environmental factors and diversity on the local biostability in diff erent types of reservoirs.展开更多
Dominant species may strongly influence biotic conditions and interact with other species,and thus are important drivers of community dynamics and ecosystem functioning,particularly in the stressed environment of alpi...Dominant species may strongly influence biotic conditions and interact with other species,and thus are important drivers of community dynamics and ecosystem functioning,particularly in the stressed environment of alpine grasslands.However,the effects of dominant species on the community stability of different ecosystems remain poorly understood.We examined the mechanisms underlying temporal stability(2014-2020 year)of aboveground productivity and community stability in four alpine grasslands(alpine meadow,alpine meadow steppe,alpine steppe and alpine desert steppe)of the northern Tibetan with different species composition and dominance.Our results showed that community stability was significantly higher in the alpine meadow than in the other three types of grasslands.This difference was mainly attributed to the higher compensatory effect and selection effect in the alpine meadows.Furthermore,dominant species strongly affected community stability by increasing dominant species stability and species asynchrony.However,species richness had little effect on community stability.Our findings demonstrate that dominant species,as foundation species,may play leading roles in shaping community stability in the alpine grasslands,highlighting the importance of conserving dominant species for stable ecosystem functioning in these fragile ecosystems under increasing environmental fluctuations.展开更多
Aims Long-term heavy grazing reduces plant diversity and ecosystem function by intensifying nitrogen(N)and water limitation.In contrast,the absence of biomass removal can cause species loss by elevating light competit...Aims Long-term heavy grazing reduces plant diversity and ecosystem function by intensifying nitrogen(N)and water limitation.In contrast,the absence of biomass removal can cause species loss by elevating light competition and weakening community stability,which is exacerbated by N and water enrichment.Hence,how to maintain species diversity and community stability is still a huge challenge for sustainable management of worldwide grasslands.Methods We conducted a 4-year manipulated experiment in six long-term grazing blocks to explore combination of resource additions and biomass removal(increased water,N and light availability)on species richness and community stability in semiarid grasslands of Inner Mongolia,China.Important Findings In all blocks treated with the combination of resource additions and biomass removal,primary productivity increased and species richness and community stability were maintained over 4 years of experiment.At both species and plant functional group(PFG)levels,the aboveground biomass of treated plants remained temporally stable in treatments with the combination of N and/or water addition and biomass removal.The maintenance of species richness was primarily caused by the biomass removal,which could increase the amount of light exposure for grasses under resource enrichment.Both species asynchrony and stability of PFGs contributed to the high temporal stability observed in these communities.Our results indicate that management practices of combined resource enrichment with biomass removal,such as grazing or mowing,could not only enhance primary productivity but also maintain plant species diversity,species asynchrony and community stability.Furthermore,as overgrazing-induced degradation and resource enrichment-induced biodiversity loss continue to be major problems worldwide,our findings have important implications for adaptive management in semiarid grasslands and beyond.展开更多
Biotic indicators have been widely used to monitor wetland health. However, few studies have explicitly evaluated if plant diversity could serve as a useful community-level indicator of wetland stability,especially wh...Biotic indicators have been widely used to monitor wetland health. However, few studies have explicitly evaluated if plant diversity could serve as a useful community-level indicator of wetland stability,especially when wetlands are confronted with anthropogenic perturbations. Based on three-year record of wetland plant species abundance in Napahai plateau wetland, Shangri-la under the influence of varying anthropogenic perturbation types, our study tests the impact of such perturbations on plant richness and the relationship between ecosystem temporal stability and plant richness, and further assesses the effectiveness of using plant diversity indicator to probe ecosystem temporal stability of Napahai plateau wetland and the potential mechanisms. The results showed that anthropogenic perturbations could have contributed significantly to realistic variation in plant diversity, and further demonstrated that ecosystem temporal stability was positively related to realistic variation in plant diversity. In particular, communities with high levels of diversity might have better capacity to dampen perturbation impacts than communities with low levels of diversity, and statistical averaging could have played an important role in causing greater stability in more diverse communities. Also, asynchrony might have a stabilizing effect on community stability, and diversity could have stabilized communities through both species asynchrony and population stability propagation. Therefore, our results suggest that plant diversity could be used as a useful indicator of the stability conditions of plateau wetland ecosystems confronted with anthropogenic perturbations, and the preservation of plant communities at sufficient abundance and diversity is necessary for maintaining healthy plateau wetlands and for sustaining their essential ecosystem functions and services.展开更多
Species diversity and stability of natural secondary communities in different layers with different cutting intensities 10 years later were investigated by calculating Marglef Richness index（R）,Shannon-Wiener divers...Species diversity and stability of natural secondary communities in different layers with different cutting intensities 10 years later were investigated by calculating Marglef Richness index（R）,Shannon-Wiener diversity index（H）,Simpson diversity index（P）,and Pielou Evenness index（J）.Results show that the values of R,H and P among different layers are listed in a decreasing order：the shrub layer the arbor layer the herb layer,all the three indices values reach the maximum under medium selective cutting intensity after 10 years.The J value of the shrub layer shows a concave parabolic change with the increase in cutting intensity;it shows a linear increase for the arbor layer,whereas the J value of the herb layer shows an opposite change pattern.The values of R at different cutting intensities had high significant difference,but other indices had not significant difference.The stability of communities at different cutting intensities after 10 years is non-cutting low selective cutting intensity medium selective cutting intensity high selective cutting intensity extra-high intensity clear cutting.The stability of communities at different cutting intensities after 10 years shows that the greater cutting intensities,the worse the stability is.展开更多
Climate change and anthropogenic activities are reshaping dryland ecosystems globally at an unprecedented pace,jeopardizing their stability.The stability of these ecosystems is crucial for maintaining ecological balan...Climate change and anthropogenic activities are reshaping dryland ecosystems globally at an unprecedented pace,jeopardizing their stability.The stability of these ecosystems is crucial for maintaining ecological balance and supporting local communities.Yet,the mechanisms governing their stability are poorly understood,largely due to the scarcity of comprehensive field data.Here we show the patterns of community temporal stability and its determinants across an aridity spectrum by integrating a transect survey across China's drylands with remote sensing.Our results revealed a U-shaped relationship between community temporal stability and aridity,with a pivotal shift occurring around an aridity level of 0.88.In less arid areas(aridity level below 0.88),enhanced precipitation and biodiversity were associated with increased community productivity and stability.Conversely,in more arid zones(aridity level above 0.88),elevated soil organic carbon and biodiversity were linked to greater fluctuations in community productivity and reduced stability.Our study identifies a critical aridity threshold that precipitates significant changes in community stability in China's drylands,underscoring the importance of distinct mechanisms driving ecosystem stability in varying aridity contexts.These insights are pivotal for developing informed ecosystem management and policy strategies tailored to the unique challenges of dryland conservation.展开更多
The community stability of coral reefs and fish is the focus of ecological monitoring of coral reefs.Among them,the realization of effective metrics of variations in reef fish communities(i.e.,the combined communities...The community stability of coral reefs and fish is the focus of ecological monitoring of coral reefs.Among them,the realization of effective metrics of variations in reef fish communities(i.e.,the combined communities of coral reefs and fish)is important for analyzing the stability of communities as well as maintaining the ecological balance of coral reefs.Based on coral reef and fish data collected at St.John’s Island from 2004 to 2010,this study proposes a symbiotic graph modeling method to express the biological relationships of reef fish communities,and a Pyramid Match graph kernel method for fusing Attributes(PMA)to quantify community fluctuations to measure interannual variability of communities.The results showed that the community similarity was low in 2006,2007,and 2008.The total coral cover rate in the study area decreased by 32.04% from 2006 to 2007 and increased by 24% in 2008.The total number of fish fell from 3780 in 2006 to 2596 in 2007 and rose to 6249 in 2008.Among them,the proportion of herbivorous fish decreased to 30.84% in 2007.Furthermore,we have combined the Louvain algorithm with the proposed PMA method to effectively identify the regions that should be prioritized for protection.Experiments were conducted on real datasets with good results,demonstrating the potential of the proposed method to assist in the analysis of community stability and identification of priority conservation areas.展开更多
Ecological water replenishment(EWR)is an important strategy for river restoration globally,but timely evaluation of its ecological effects at a large spatiotemporal scale to further adjust the EWR schemes is of great ...Ecological water replenishment(EWR)is an important strategy for river restoration globally,but timely evaluation of its ecological effects at a large spatiotemporal scale to further adjust the EWR schemes is of great challenge.Here,we examine the impact of EWR on microeukaryotic plankton communities in three distinct river ecosystems through environmental DNA(eDNA)metabarcoding.The three ecosystems include a long-term cut-off river,a short-term connected river after EWR,and long-term connected rivers.We analyzed community stability by investigating species composition,stochastic and deterministic dynamics interplay,and ecological network robustness.We found that EWR markedly reduced the diversity and complexity of microeukaryotic plankton,altered their community dynamics,and lessened the variation within the community.Moreover,EWR disrupted the deterministic patterns of community organization,favoring dispersal constraints,and aligning with trends observed in naturally connected rivers.The shift from an isolated to a temporarily connected river appeared to transition community structuring mechanisms from deterministic to stochastic dominance,whereas,in permanently connected rivers,both forces concurrently influenced community assembly.The ecological network in temporarily connected rivers post-EWR demonstrated significantly greater stability and intricacy compared to other river systems.This shift markedly bolstered the resilience of the ecological network.The eDNA metabarcoding insights offer a novel understanding of ecosystem resilience under EWR interventions,which could be critical in assessing the effects of river restoration projects throughout their life cycle.展开更多
The significance of microbes for ecosystem functioning is well known;however,within a single system,the relative contributions of keystone and rare taxa to soil microbial functions are less well quantified,as are thei...The significance of microbes for ecosystem functioning is well known;however,within a single system,the relative contributions of keystone and rare taxa to soil microbial functions are less well quantified,as are their shared or unique responses to abiotic conditions.Furthermore,their associations with tree community composition in natural forest ecosystems are not well understood.In this study,a total of 1287 soil samples were collected from a 20-ha subtropical forest plot and analyzed using high-throughput sequencing.Based on co-occurrence network analyses,we conducted a comparison of the associations between keystone and rare taxa with the structure,functions and stability of soil microbial communities.Additionally,we examined their associations with tree community composition.Results showed that keystone taxa made a significantly greater contribution than rare taxa in all comparisons of microbial functions and stability.Keystone taxa had direct effects on microbial community structure and also mediated indirect effects of abiotic conditions.Neither effect was evident for rare taxa.The importance of keystone taxa also extended to aboveground composition,where tree community composition was more closely associated with keystone taxa than with rare taxa.While it may still be premature to establish causality,our study represents one of the initial attempts to compare the relative importance of keystone and rare microbial taxa in forest soils.These findings offer the potential to improve natural forest ecosystem functioning and tree diversity through the manipulation of a small number of keystone soil microbial taxa,as has been demonstrated in agroecosystems.展开更多
●Bacterial richness declined but fungal richness increased under salinization.●Bacteria did not become interactively compact or facilitative under salinization.●Fungi exhibited more compartmentalized and competitiv...●Bacterial richness declined but fungal richness increased under salinization.●Bacteria did not become interactively compact or facilitative under salinization.●Fungi exhibited more compartmentalized and competitive patterns under salinization.●Fungal stability showed steeper increases under salinization than bacterial stability.Soil salinization is a typical environmental challenge in arid regions worldwide.Salinity stress increases plant convergent adaptations and facilitative interactions and thus destabilizes communities.Soil bacteria and fungi have smaller body mass than plants and are often efficient against soil salinization,but how the stability of bacterial and fungal communities change with a wide range of soil salinity gradient remains unclear.Here,we assessed the interactions within both bacterial and fungal communities along a soil salinity gradient in the Taklamakan desert to examine(i)whether the stability of bacterial and fungal communities decreased with soil salinity,and(ii)the stability of which community decreased more with soil salinity,bacteria or fungi.Our results showed that the species richness of soil fungi increased but that of soil bacteria decreased with increasing salinity in topsoils.Fungal communities became more stable under soil salinization,with increasing compartmentalization(i.e.,modularity)and proportion of competitions(i.e.,negative:positive cohesion)as salinity increased.Bacterial communities exhibited no changes in modularity with increasing salinity and smaller increases in negative:positive cohesion under soil salinization compared to fungal communities.Our results suggest that,by altering interspecific interactions,soil salinization increases the stability of fungal not bacterial communities in extreme environments.展开更多
Stability is a fundamental ecological property of the gut microbiota and is associated with host health.Numerous studies have shown that unbalanced dietary components disturb the gut microbial composition and thereby ...Stability is a fundamental ecological property of the gut microbiota and is associated with host health.Numerous studies have shown that unbalanced dietary components disturb the gut microbial composition and thereby contribute to the onset and progression of disease.However,the impact of unbalanced diets on the stability of the gut microbiota is poorly understood.In the present study,four-week-old mice were fed a plant-based diet high in refined carbohydrates or a high-fat diet for four weeks to simulate a persistent unbalanced diet.We found that persistent unbalanced diets significantly reduced the gut bacterial richness and increased the complexity of bacterial co-occurrence networks.Furthermore,the gut bacterial response to unbalanced diets was phylogenetically conserved,which reduced network modularity and enhanced the proportion of positive associations between community taxon,thereby amplifying the co-oscillation of perturbations among community species to destabilize gut microbial communities.The disturbance test revealed that the gut microbiota of mice fed with unbalanced diets was less resistant to antibiotic perturbation and pathogenic bacteria invasion.This study may fill a gap in the mechanistic understanding of the gut microbiota stability in response to diet and provide new insights into the gut microbial ecology.展开更多
Community and ecosystem changes are happening in the pristine boreal forest ecosystem of the Yukon for 2 reasons.First,climate change is affecting the abiotic environment(temperature,rainfall and growing season)and dr...Community and ecosystem changes are happening in the pristine boreal forest ecosystem of the Yukon for 2 reasons.First,climate change is affecting the abiotic environment(temperature,rainfall and growing season)and driving changes in plant productivity and predator-prey interactions.Second,simultaneously change is occurring because of mammal species reintroductions and rewilding.The key ecological question is the impact these faunal changes will have on trophic dynamics.Primary productivity in the boreal forest is increasing because of climatic warming,but plant species composition is unlikely to change significantly during the next 50-100 years.The 9-10-year population cycle of snowshoe hares will persist but could be reduced in amplitude if winter weather increases predator hunting efficiency.Small rodents have increased in abundance because of increased vegetation growth.Arctic ground squirrels have disappeared from the forest because of increased predator hunting efficiency associated with shrub growth.Reintroductions have occurred for 2 reasons:human reintroductions of large ungulates and natural recolonization of mammals and birds extending their geographic ranges.The deliberate rewilding of wood bison(Bison bison)and elk(Cervus canadensis)has changed the trophic structure of this boreal ecosystem very little.The natural range expansion of mountain lions(Puma concolor),mule deer(Odocoileus hemionus)and American marten(Martes americana)should have few ecosystem effects.Understanding potential changes will require long-term monitoring studies and experiments on a scale we rarely deem possible.Ecosystems affected by climate change,species reintroductions and human alteration of habitats cannot remain stable and changes will be critically dependent on food web interactions.展开更多
Nitrogen(N)deposition decreases the temporal stability of ecosystem aboveground biomass production(ecosystem stability).However,little is known about how the responses of ecosystem stability differ based on seasonal N...Nitrogen(N)deposition decreases the temporal stability of ecosystem aboveground biomass production(ecosystem stability).However,little is known about how the responses of ecosystem stability differ based on seasonal N enrichment.By adding N in autumn,winter,or growing season,from October 2014 to May 2020,in a temperate grassland in northern China,we found that only N addition in autumn resulted in a significantly positive correlation between ecosystem mean aboveground net primary productivity(ANPP)and its standard deviation and significantly reduced ecosystem stability.Autumn N-induced reduction in ecosystem stability was associated with the vanished negative effect of community-wide species asynchrony(asynchronous dynamics among populations to environmental perturbations)on the standard deviation of ecosystem ANPP in combination with the emerged positive effect of dominance(Simpson's dominance index that indicates the relative weight of dominant species in a community).Our findings indicate that autumn N addition might overestimate the negative effect of annual atmospheric N deposition on ecosystem stability,suggesting that to better evaluate the influence of N deposition in temperate grasslands,both field experiments and global modeling should consider not only the annual N load but also its seasonal dynamics.Moreover,further studies should pay more attention to the alteration in the ecosystem temporal deviations,which might be more sensitive to human-induced environmental changes.展开更多
基金financial support provided by the Research and Application Demonstration of Native Ecological Grass Seed Breeding Technology in“Black Soil Beaches”(2024-SF-101)。
文摘Plant diversity plays a crucial role in maintaining the stability of ecological function.Based on field investigations and experimental analyses,artificial grassland plots with varying sowing times,adjacent natural grassland(CK),and open-pit coal mine dumps in the Muli mining area of Qinghai Province were selected as research subjects for this study.The characteristics of plant diversity and community stability were measured and analyzed,and the relationships between these factors and their influencing variables were evaluated.The results indicated significant differences in the vegetation community characteristics and plant diversity among the various grasslands.Coverage,aboveground biomass,belowground biomass,soil total nitrogen,and soil total carbon were the highest when the growth period was three years.Plant diversity and community stability in the natural grassland were significantly greater than that in the artificial grassland and open-pit coal mine dumps.A significant positive correlation was observed between plant diversity and community stability,suggesting that plant diversity can serve as an index of community stability.The order of stability,from highest to lowest,was CK>11a>10a>8a>9a>6a>7a>3a>2a>1a>0a.Years were identified as the primary factors affecting plant diversity and community stability by altering the soil pH.These results elucidate the relationships and driving mechanisms between plant diversity and community stability in grasslands,providing a scientific basis for maintaining community stability in artificial grassland ecosystems in alpine mining areas.
基金Supported by the Key Research and Development Program of Guangdong Province(No.2019B110205004)the Science and Technology Foundation of Guizhou Province(Nos.[2020]4Y009,[2020]6009)。
文摘Relationship between biodiversity and ecosystem function is one of the core issues in ecological research.Phytoplankton,as the main producer of aquatic ecosystem,its diversity,productivity,and community stability are of great signifi cance to reveal ecosystem function.There are signifi cant diff erences in hydrodynamics,water retention time,and phytoplankton community structure between river-type reservoir and newly built lake-type reservoir.The comparative analysis of phytoplankton community stability between the two types of reservoir has not been reported.Jiuquwan Reservoir(river-type)and Taihu Reservoir(lake-type),the two reservoirs in the Dongjiang River source area of Zhujiang(Pearl)River Basin,were selected for comparison in terms of multi-year operation vs.new impoundment,river-type vs.lake-type,and shallow water vs.sub-deep water reservoirs.Samples were collected in dry season(December 2019),normal season(March 2020),and wet season(August 2020),on which the phytoplankton diversity and productivity of the two reservoirs,and the relationship and diff erence of community stability were examined.Results show that(1)the number of phytoplankton species in Jiuquwan Reservoir decreased comparing that before algal bloom and the restoration treatment,while that in Taihu Reservoir increased compared with that before the impoundment of the reservoir.There was no signifi cant diff erence in functional groups and species number between the two reservoirs(P>0.05);(2)the biological stability,diversity,productivity,and resource utilization effi ciency of newly built lake-type reservoir were higher than those of multi-year river-type reservoir.In addition,the utilization effi ciency of phytoplankton resources was the highest in wet season in both reservoirs.The increases in biodiversity,richness,and evenness promoted the stability of the community,while increases in productivity and resource utilization effi ciency weakened the stability of the community;(3)community stability was aff ected by both biotic and abiotic factors,and hydrodynamic index was the main factor.This study is helpful to understand the relationship and diff erences in phytoplankton diversity,productivity and community stability in diff erent types of reservoirs,and provides a guidance for maintaining the stability of reservoir water ecosystem and protecting the biodiversity.The relationships between phytoplankton diversity,productivity,and community stability will be investigated in depth,for which a long-term observation will be conducted on the impact of environmental factors and diversity on the local biostability in diff erent types of reservoirs.
基金supported by the National Natural Science Foundation of China(31870406,42071066)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0302).
文摘Dominant species may strongly influence biotic conditions and interact with other species,and thus are important drivers of community dynamics and ecosystem functioning,particularly in the stressed environment of alpine grasslands.However,the effects of dominant species on the community stability of different ecosystems remain poorly understood.We examined the mechanisms underlying temporal stability(2014-2020 year)of aboveground productivity and community stability in four alpine grasslands(alpine meadow,alpine meadow steppe,alpine steppe and alpine desert steppe)of the northern Tibetan with different species composition and dominance.Our results showed that community stability was significantly higher in the alpine meadow than in the other three types of grasslands.This difference was mainly attributed to the higher compensatory effect and selection effect in the alpine meadows.Furthermore,dominant species strongly affected community stability by increasing dominant species stability and species asynchrony.However,species richness had little effect on community stability.Our findings demonstrate that dominant species,as foundation species,may play leading roles in shaping community stability in the alpine grasslands,highlighting the importance of conserving dominant species for stable ecosystem functioning in these fragile ecosystems under increasing environmental fluctuations.
基金supported by grants from the National Natural Science Foundation of China(31630010 and 31320103916).
文摘Aims Long-term heavy grazing reduces plant diversity and ecosystem function by intensifying nitrogen(N)and water limitation.In contrast,the absence of biomass removal can cause species loss by elevating light competition and weakening community stability,which is exacerbated by N and water enrichment.Hence,how to maintain species diversity and community stability is still a huge challenge for sustainable management of worldwide grasslands.Methods We conducted a 4-year manipulated experiment in six long-term grazing blocks to explore combination of resource additions and biomass removal(increased water,N and light availability)on species richness and community stability in semiarid grasslands of Inner Mongolia,China.Important Findings In all blocks treated with the combination of resource additions and biomass removal,primary productivity increased and species richness and community stability were maintained over 4 years of experiment.At both species and plant functional group(PFG)levels,the aboveground biomass of treated plants remained temporally stable in treatments with the combination of N and/or water addition and biomass removal.The maintenance of species richness was primarily caused by the biomass removal,which could increase the amount of light exposure for grasses under resource enrichment.Both species asynchrony and stability of PFGs contributed to the high temporal stability observed in these communities.Our results indicate that management practices of combined resource enrichment with biomass removal,such as grazing or mowing,could not only enhance primary productivity but also maintain plant species diversity,species asynchrony and community stability.Furthermore,as overgrazing-induced degradation and resource enrichment-induced biodiversity loss continue to be major problems worldwide,our findings have important implications for adaptive management in semiarid grasslands and beyond.
基金supported by National Natural Science Foundation of China and Yunnan province (Grant No.U0933601)Natural Science Foundation of Yunnan (Grant No.2009CC024)+1 种基金National Basic Research Program of China/973 Program (Grant No.2010CB434807)he Middle Aged Academic and Technical Leader Project of Yunnan Province (Grant No.2010CI016)
文摘Biotic indicators have been widely used to monitor wetland health. However, few studies have explicitly evaluated if plant diversity could serve as a useful community-level indicator of wetland stability,especially when wetlands are confronted with anthropogenic perturbations. Based on three-year record of wetland plant species abundance in Napahai plateau wetland, Shangri-la under the influence of varying anthropogenic perturbation types, our study tests the impact of such perturbations on plant richness and the relationship between ecosystem temporal stability and plant richness, and further assesses the effectiveness of using plant diversity indicator to probe ecosystem temporal stability of Napahai plateau wetland and the potential mechanisms. The results showed that anthropogenic perturbations could have contributed significantly to realistic variation in plant diversity, and further demonstrated that ecosystem temporal stability was positively related to realistic variation in plant diversity. In particular, communities with high levels of diversity might have better capacity to dampen perturbation impacts than communities with low levels of diversity, and statistical averaging could have played an important role in causing greater stability in more diverse communities. Also, asynchrony might have a stabilizing effect on community stability, and diversity could have stabilized communities through both species asynchrony and population stability propagation. Therefore, our results suggest that plant diversity could be used as a useful indicator of the stability conditions of plateau wetland ecosystems confronted with anthropogenic perturbations, and the preservation of plant communities at sufficient abundance and diversity is necessary for maintaining healthy plateau wetlands and for sustaining their essential ecosystem functions and services.
基金supported by National Natural Science Foundation of China (30972359, 31070567)the Natural Science Foundation of Fujian Province (No.2006J0301, No.2008J0327,No.2009J0101)+1 种基金the Science Foundation of Science Technology of Fu-jian Province (No.2007N0002, No.2006F5006, No.2007F5010)the Science Foundation of Forestry Committee of Fujian Province (Forestry Science of Fujian[2006] No.7,No.14)
文摘Species diversity and stability of natural secondary communities in different layers with different cutting intensities 10 years later were investigated by calculating Marglef Richness index（R）,Shannon-Wiener diversity index（H）,Simpson diversity index（P）,and Pielou Evenness index（J）.Results show that the values of R,H and P among different layers are listed in a decreasing order：the shrub layer the arbor layer the herb layer,all the three indices values reach the maximum under medium selective cutting intensity after 10 years.The J value of the shrub layer shows a concave parabolic change with the increase in cutting intensity;it shows a linear increase for the arbor layer,whereas the J value of the herb layer shows an opposite change pattern.The values of R at different cutting intensities had high significant difference,but other indices had not significant difference.The stability of communities at different cutting intensities after 10 years is non-cutting low selective cutting intensity medium selective cutting intensity high selective cutting intensity extra-high intensity clear cutting.The stability of communities at different cutting intensities after 10 years shows that the greater cutting intensities,the worse the stability is.
基金funded by the National Natural Science Foundation and the National Key Research and Development Program of China(Grant No.41991233,2022YFF1300405,and 41807153)C.W.was supported by the Ma Shijun Young Talent Sponsorship Program by the State Key Laboratory of Urban and Regional Ecology.
文摘Climate change and anthropogenic activities are reshaping dryland ecosystems globally at an unprecedented pace,jeopardizing their stability.The stability of these ecosystems is crucial for maintaining ecological balance and supporting local communities.Yet,the mechanisms governing their stability are poorly understood,largely due to the scarcity of comprehensive field data.Here we show the patterns of community temporal stability and its determinants across an aridity spectrum by integrating a transect survey across China's drylands with remote sensing.Our results revealed a U-shaped relationship between community temporal stability and aridity,with a pivotal shift occurring around an aridity level of 0.88.In less arid areas(aridity level below 0.88),enhanced precipitation and biodiversity were associated with increased community productivity and stability.Conversely,in more arid zones(aridity level above 0.88),elevated soil organic carbon and biodiversity were linked to greater fluctuations in community productivity and reduced stability.Our study identifies a critical aridity threshold that precipitates significant changes in community stability in China's drylands,underscoring the importance of distinct mechanisms driving ecosystem stability in varying aridity contexts.These insights are pivotal for developing informed ecosystem management and policy strategies tailored to the unique challenges of dryland conservation.
基金supported by the National Natural Science Foundation of China[No.42106190]the Science and Technology Commission of Shanghai Municipality Capacity Building Plan for Some Regional Universities and Colleges[No.20050501900].
文摘The community stability of coral reefs and fish is the focus of ecological monitoring of coral reefs.Among them,the realization of effective metrics of variations in reef fish communities(i.e.,the combined communities of coral reefs and fish)is important for analyzing the stability of communities as well as maintaining the ecological balance of coral reefs.Based on coral reef and fish data collected at St.John’s Island from 2004 to 2010,this study proposes a symbiotic graph modeling method to express the biological relationships of reef fish communities,and a Pyramid Match graph kernel method for fusing Attributes(PMA)to quantify community fluctuations to measure interannual variability of communities.The results showed that the community similarity was low in 2006,2007,and 2008.The total coral cover rate in the study area decreased by 32.04% from 2006 to 2007 and increased by 24% in 2008.The total number of fish fell from 3780 in 2006 to 2596 in 2007 and rose to 6249 in 2008.Among them,the proportion of herbivorous fish decreased to 30.84% in 2007.Furthermore,we have combined the Louvain algorithm with the proposed PMA method to effectively identify the regions that should be prioritized for protection.Experiments were conducted on real datasets with good results,demonstrating the potential of the proposed method to assist in the analysis of community stability and identification of priority conservation areas.
基金supported by the National Key Research and Development Program of China(2021YFC3201005,2021YFC3201000,and 2022YFC2601301)the Fundamental Research Funds for Central Public Welfare Scientific Research Institutes of China(2022YSKY-41)+1 种基金the National Nature Science Foundation of China(U1906223)The authors thank Yong Du in Yongding River Investment Co.Ltd for providing Fig.S2.Dr James Walter Voordeckers is acknowledged for assistance in English language modification.
文摘Ecological water replenishment(EWR)is an important strategy for river restoration globally,but timely evaluation of its ecological effects at a large spatiotemporal scale to further adjust the EWR schemes is of great challenge.Here,we examine the impact of EWR on microeukaryotic plankton communities in three distinct river ecosystems through environmental DNA(eDNA)metabarcoding.The three ecosystems include a long-term cut-off river,a short-term connected river after EWR,and long-term connected rivers.We analyzed community stability by investigating species composition,stochastic and deterministic dynamics interplay,and ecological network robustness.We found that EWR markedly reduced the diversity and complexity of microeukaryotic plankton,altered their community dynamics,and lessened the variation within the community.Moreover,EWR disrupted the deterministic patterns of community organization,favoring dispersal constraints,and aligning with trends observed in naturally connected rivers.The shift from an isolated to a temporarily connected river appeared to transition community structuring mechanisms from deterministic to stochastic dominance,whereas,in permanently connected rivers,both forces concurrently influenced community assembly.The ecological network in temporarily connected rivers post-EWR demonstrated significantly greater stability and intricacy compared to other river systems.This shift markedly bolstered the resilience of the ecological network.The eDNA metabarcoding insights offer a novel understanding of ecosystem resilience under EWR interventions,which could be critical in assessing the effects of river restoration projects throughout their life cycle.
基金supported by the National Natural Science Foundation of China 470(32071645 and 32471613)the Research Project of Baishanzu National Park(2022JBGS04 and 2023JBGS06)the Fundamental Research Funds for the Central Universities of China and the Natural Sciences and Engineering Research Council of Canada.
文摘The significance of microbes for ecosystem functioning is well known;however,within a single system,the relative contributions of keystone and rare taxa to soil microbial functions are less well quantified,as are their shared or unique responses to abiotic conditions.Furthermore,their associations with tree community composition in natural forest ecosystems are not well understood.In this study,a total of 1287 soil samples were collected from a 20-ha subtropical forest plot and analyzed using high-throughput sequencing.Based on co-occurrence network analyses,we conducted a comparison of the associations between keystone and rare taxa with the structure,functions and stability of soil microbial communities.Additionally,we examined their associations with tree community composition.Results showed that keystone taxa made a significantly greater contribution than rare taxa in all comparisons of microbial functions and stability.Keystone taxa had direct effects on microbial community structure and also mediated indirect effects of abiotic conditions.Neither effect was evident for rare taxa.The importance of keystone taxa also extended to aboveground composition,where tree community composition was more closely associated with keystone taxa than with rare taxa.While it may still be premature to establish causality,our study represents one of the initial attempts to compare the relative importance of keystone and rare microbial taxa in forest soils.These findings offer the potential to improve natural forest ecosystem functioning and tree diversity through the manipulation of a small number of keystone soil microbial taxa,as has been demonstrated in agroecosystems.
基金support for this work is Intergovernmental International Cooperation on Scientific and Technological Innovation as Part of National Key Research and Development Program(2021YFE0114500)the National Natural Science Foundation of China(41730638 and U1803342)+1 种基金the Agricultural Science and Technology Innovation Program(ASTIP)K.C.Wong Education Foundation(GJTD-2020-14).
文摘●Bacterial richness declined but fungal richness increased under salinization.●Bacteria did not become interactively compact or facilitative under salinization.●Fungi exhibited more compartmentalized and competitive patterns under salinization.●Fungal stability showed steeper increases under salinization than bacterial stability.Soil salinization is a typical environmental challenge in arid regions worldwide.Salinity stress increases plant convergent adaptations and facilitative interactions and thus destabilizes communities.Soil bacteria and fungi have smaller body mass than plants and are often efficient against soil salinization,but how the stability of bacterial and fungal communities change with a wide range of soil salinity gradient remains unclear.Here,we assessed the interactions within both bacterial and fungal communities along a soil salinity gradient in the Taklamakan desert to examine(i)whether the stability of bacterial and fungal communities decreased with soil salinity,and(ii)the stability of which community decreased more with soil salinity,bacteria or fungi.Our results showed that the species richness of soil fungi increased but that of soil bacteria decreased with increasing salinity in topsoils.Fungal communities became more stable under soil salinization,with increasing compartmentalization(i.e.,modularity)and proportion of competitions(i.e.,negative:positive cohesion)as salinity increased.Bacterial communities exhibited no changes in modularity with increasing salinity and smaller increases in negative:positive cohesion under soil salinization compared to fungal communities.Our results suggest that,by altering interspecific interactions,soil salinization increases the stability of fungal not bacterial communities in extreme environments.
基金financially supported by Key Research&Development projects of Shaanxi Province(No.2019ZDXM3-02 to Shanting Zhao and Xuejun Chai)Foundation for top talent recruitment of Xi’an Medical College(No.2018RCYJ04 to Xuejun Chai)+1 种基金“Tianfu Scholar”distinguished expert program of Sichuan Province(No.2020-120 to Shanting Zhao)16th Eucommia Research Grant from Eucommia ulmoides Research Association of Japan(2020 to Shanting Zhao).
文摘Stability is a fundamental ecological property of the gut microbiota and is associated with host health.Numerous studies have shown that unbalanced dietary components disturb the gut microbial composition and thereby contribute to the onset and progression of disease.However,the impact of unbalanced diets on the stability of the gut microbiota is poorly understood.In the present study,four-week-old mice were fed a plant-based diet high in refined carbohydrates or a high-fat diet for four weeks to simulate a persistent unbalanced diet.We found that persistent unbalanced diets significantly reduced the gut bacterial richness and increased the complexity of bacterial co-occurrence networks.Furthermore,the gut bacterial response to unbalanced diets was phylogenetically conserved,which reduced network modularity and enhanced the proportion of positive associations between community taxon,thereby amplifying the co-oscillation of perturbations among community species to destabilize gut microbial communities.The disturbance test revealed that the gut microbiota of mice fed with unbalanced diets was less resistant to antibiotic perturbation and pathogenic bacteria invasion.This study may fill a gap in the mechanistic understanding of the gut microbiota stability in response to diet and provide new insights into the gut microbial ecology.
基金Research funding was provided by the Natural Science and Engineering Research Council of Canada(RB,CK,SB)and Environment Yukon(TJ,ST).
文摘Community and ecosystem changes are happening in the pristine boreal forest ecosystem of the Yukon for 2 reasons.First,climate change is affecting the abiotic environment(temperature,rainfall and growing season)and driving changes in plant productivity and predator-prey interactions.Second,simultaneously change is occurring because of mammal species reintroductions and rewilding.The key ecological question is the impact these faunal changes will have on trophic dynamics.Primary productivity in the boreal forest is increasing because of climatic warming,but plant species composition is unlikely to change significantly during the next 50-100 years.The 9-10-year population cycle of snowshoe hares will persist but could be reduced in amplitude if winter weather increases predator hunting efficiency.Small rodents have increased in abundance because of increased vegetation growth.Arctic ground squirrels have disappeared from the forest because of increased predator hunting efficiency associated with shrub growth.Reintroductions have occurred for 2 reasons:human reintroductions of large ungulates and natural recolonization of mammals and birds extending their geographic ranges.The deliberate rewilding of wood bison(Bison bison)and elk(Cervus canadensis)has changed the trophic structure of this boreal ecosystem very little.The natural range expansion of mountain lions(Puma concolor),mule deer(Odocoileus hemionus)and American marten(Martes americana)should have few ecosystem effects.Understanding potential changes will require long-term monitoring studies and experiments on a scale we rarely deem possible.Ecosystems affected by climate change,species reintroductions and human alteration of habitats cannot remain stable and changes will be critically dependent on food web interactions.
基金funded by the National Natural Science Foundation of China (32122055 and 32071603)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA26020101).
文摘Nitrogen(N)deposition decreases the temporal stability of ecosystem aboveground biomass production(ecosystem stability).However,little is known about how the responses of ecosystem stability differ based on seasonal N enrichment.By adding N in autumn,winter,or growing season,from October 2014 to May 2020,in a temperate grassland in northern China,we found that only N addition in autumn resulted in a significantly positive correlation between ecosystem mean aboveground net primary productivity(ANPP)and its standard deviation and significantly reduced ecosystem stability.Autumn N-induced reduction in ecosystem stability was associated with the vanished negative effect of community-wide species asynchrony(asynchronous dynamics among populations to environmental perturbations)on the standard deviation of ecosystem ANPP in combination with the emerged positive effect of dominance(Simpson's dominance index that indicates the relative weight of dominant species in a community).Our findings indicate that autumn N addition might overestimate the negative effect of annual atmospheric N deposition on ecosystem stability,suggesting that to better evaluate the influence of N deposition in temperate grasslands,both field experiments and global modeling should consider not only the annual N load but also its seasonal dynamics.Moreover,further studies should pay more attention to the alteration in the ecosystem temporal deviations,which might be more sensitive to human-induced environmental changes.
