Understanding how and why assemblage dissimilarity changes along spatial gradient is a great challenge in ecology,because answers to these questions depend on the analytical types,dimensions,and components of beta div...Understanding how and why assemblage dissimilarity changes along spatial gradient is a great challenge in ecology,because answers to these questions depend on the analytical types,dimensions,and components of beta diversity we concerned.To obtain a comprehensive understanding of assemblage dissimilarity and its implications for biodiversity conservation in the Himalayas,we explored the elevational patterns and determinants of beta diversity and its turnover and nestedness components of pairwise and multiple types and taxonomic and phylogenetic dimensions simultaneously.Patterns of beta diversity and their components of different types and dimensions were calculated based on 96 sampling quadrats along an 1800-5400 m elevational gradient.We examined whether and how these patterns differed from random expectations using null models.Furthermore,we used random forest methods to quantify the role of environmental variables representing climate,topography,and human disturbance in determining these patterns.We found that beta diversity and its turnover component,regardless of its types and dimensions,shown a hump-shaped elevational patterns.Both pairwise and multiple phylogenetic beta diversity were remarkably lower than their taxonomic counterpart.These patterns were significantly less than random expectation and were mostly associated with climate variables.In summary,our results suggested that assemblage dissimilarity of seed plants was mostly originate from the replacement of closely related species determined by climate-driven environmental filtering.Accordingly,conservation efforts should better cover elevations with different climate types to maximalize biodiversity conservation,rather than only focus on elevations with highest species richness.Our study demonstrated that comparisons of beta diversity of different types,dimensions,and components could be conductive to consensus on the origin and mechanism of assemblage dissimilarity.展开更多
Global change threatens mountainous plant communities,causing habitat displacement.Phylogenetic studies reveal evolutionary and ecological processes in community assembly.We examined taxonomic and phylogenetic diversi...Global change threatens mountainous plant communities,causing habitat displacement.Phylogenetic studies reveal evolutionary and ecological processes in community assembly.We examined taxonomic and phylogenetic diversity in Andean Páramos across altitudes.Our hypotheses were that increasing altitude is an environmental filter,as altitude is expected to be a stronger variable than soil depth.The Páramos,alpine vegetation in the Andes,range from 3,000 to 4,700 meters,with our plots spanning 3,200 to 4,100 meters.Sampling was conducted at six altitudinal levels,measuring soil depth,taxonomic,and phylogenetic diversity.Data analysis employed multiple linear regressions and mixed-effects models to assess the effects of soil depth and altitude.We sampled 110 angiosperm species from 70 genera,30 families,and 18 orders.Asterales and Poales were prominent.Species richness generally decreased with altitude but increased at the summit.Soil depth affected species richness and taxonomic diversity,while altitude did not.Phylogenetic diversity increased with soil depth and decreased with altitude.Phylogenetic turnover increased with altitude differences.The hypothesis that increasing altitude intensifies environmental filtering in the altitudeadapted Páramos resulting in lower species richness and more clustered phylogenetic structures,was rejected.Although species richness,Shannon diversity,and Simpson diversity decreased initially with increasing altitude,this trend was not linear because the summit presented intermediate species richness.The hypothesis that altitude is a stronger explanatory variable than soil depth was also rejected.Despite expectations,taxonomic results did not support altitude as an environmental filter,but soil depth.Greater altitude differences increased beta phylogenetic dissimilarity,supporting niche conservatism.展开更多
Elucidating how multiple factors affect biodiversity and plant community assembly is a central issue in ecology,especially in vulnerable ecosystems such as tropical mountains.These studies are more relevant in global ...Elucidating how multiple factors affect biodiversity and plant community assembly is a central issue in ecology,especially in vulnerable ecosystems such as tropical mountains.These studies are more relevant in global warming scenarios that induce the upward displacement of plant species towards reduced habitats and hostile environments in tropical mountains.This study aimed to analyze how altitude affects taxonomic and phylogenetic diversity in plant communities of tropical mountains.Thus,we tested if(i)increased altitude works as an environmental filtering promoting decreased species richness,decreased phylogenetic diversity,and increased phylogenetic clustering in these tropical mountains;and if(ii)plant communities of high altitude in tropical mountains are also result of recent diversification with plant species recently split shortening phylogenetic distances between closest related species.We tested effects of altitude on species richness and phylogenetic metrics using linear mixed-effects models.Mount Haleakala presented 114 species,Mount Kilimanjaro presented 231 species and Mount Purace presented 280 species.We found an environmental filtering effect with increasing altitude causing phylogenetic clustering,decreased phylogenetic diversity and decreased species richness.The decreasing phylogenetic distances between closest relatives are congruent with neo-endemics,suggesting recent plant diversification in high altitudes of tropical mountains,possibly driven by geographic isolation and environmental heterogeneity.Consequences of global warming should be monitored in tropical mountains focusing on distribution shifts.展开更多
Grazing exclusion is one of the most efficient approaches to restore degraded grassland but may negatively affects the recovery of species diversity. Changes in plant species diversity should be a consequence of the e...Grazing exclusion is one of the most efficient approaches to restore degraded grassland but may negatively affects the recovery of species diversity. Changes in plant species diversity should be a consequence of the ecological assembly process. Local community assembly is influenced by environmental filtering, biotic interactions, and dispersal. However, how these factors potentially contribute to changes to species diversity is poorly understood, especially in harsh environments. In this study, two management sites within a Stipa breviflora desert steppe community（typical natural steppe） were selected in northern China. In one of the two management sites, grazing has been excluded since 2010 and in the other with open grazing by sheep. In August 2016, three plots were established and 100 sampling units were created within each plot in a 5 m×5 m area at the two management sites. To assess the effects of grazing exclusion on S. breviflora steppe, we analyzed the vegetation biomass, species diversity,soil organic carbon, and soil particle size distribution using paired T-tests. In addition, variation partitioning was applied to determine the relative importance of environmental filtering and dispersal limitation. Null mode analysis was used to quantify the influence of biotic interactions in conjunction with Eco Sim niche overlap and co-occurrence values. Our results demonstrated that（1） species diversity significantly decreased and the main improvements in soil quality occurred in the topsoil 0–10 cm after the grazing exclusion;（2） environmental filtering was important for community assembly between grazed and fenced grassland and this appears particularly true for soil particle size distribution, which may be well correlated with soil hydrological processes; and（3） however, competitive exclusion may play a significant role within the exclusion. The multiple pathways of assembly may collectively determine negative effects on the restoration of species diversity. Therefore, designers should be aware of the risk of reducing grazing exclusion-induced species diversity and account for manipulating processes. This in turn will reduce dominant species and promote environmental heterogeneity to maximize species diversity in semi-arid regions.展开更多
Background:Disentangling the relative roles of environmental filtering and spatial processes in structuring ecological communities is a central topic in metacommunity ecology.Metacommunity ecology in the temperate riv...Background:Disentangling the relative roles of environmental filtering and spatial processes in structuring ecological communities is a central topic in metacommunity ecology.Metacommunity ecology in the temperate river ecosystems has been well developed,while less attention has been paid to subtropical urban river networks.Here,we examined the ecological factors and seasonal difference in structuring macroinvertebrates metacommunity assembly in the subtropical urban river networks in Shenzhen,South China.Results:Our results revealed that there was no significant distinction of macroinvertebrate community composition among seasons,with only the relative abundance of Mollusca and Odonata significantly differed in both wet and dry seasons.One possible explanation was that most macroinvertebrates are generally pollution-tolerant taxa characterized with nonseasonal life cycle.In addition,distance-based redundancy analysis and variation partitioning approach revealed that metacommunity was determined equally by the environmental and dispersal-related factors.Further,our results showed that,although a slight temporal variation of relative contribution,the identity and explanation power of ecological factors were different among seasons.Specifically,stronger environmental filtering structuring community dynamics was observed in the dry than wet seasons,which might be owing to higher environmental heterogeneity under a low water-flow condition.Moreover,we detected that the influence of spatial processes was stronger in the wet than dry seasons,indicating an obvious dispersal processes due to high connectivity among sites.Conclusion:Overall,our results revealed that environmental and spatial factors equally explained variations of macroinvertebrate metacommunity,implying the necessity of considering dispersal-related processes structuring ecological communities in river bioassessment programs.Moreover,degraded habitat conditions and water quality were the predominant factors that affected macroinvertebrate communities,indicating the significance and feasibility of improving local abiotic conditions to sustain local biodiversity.Further,our findings revealed the importance of seasonal dynamics of these urban river networks in structuring macroinvertebrate metacommunity.Thereby,our study improves the understanding of ecological processes governing macroinvertebrate metacommunity and underlines the idea that community ecology studies should go beyond the single snapshot survey in river networks.展开更多
Herbaceous plants are an essential component of forest diversity and driver of ecosystem processes.However,because the growth forms and life-history strategies of herbaceous plants differ from those of woody plants,it...Herbaceous plants are an essential component of forest diversity and driver of ecosystem processes.However,because the growth forms and life-history strategies of herbaceous plants differ from those of woody plants,it is unclear whether the mechanisms that drive patterns plant diversity and community structure in these two plant groups are the same.In this study,we determined whether herb and woody plant communities have similar patterns and drivers of alpha-and beta-diversity.We compared species richness,distribution,and abundance of herbs to woody seedlings in a 20-ha Donglingshan warmtemperate forest(Donglingshan FDP),China.We also determined whether variation in patterns of species richness and composition are better explained by environmental or spatial variables.Herbaceous plants accounted for 72%of all species(81 herbaceous,31 woody)recorded.Alpha-and beta-diversity were higher in herbs than in woody seedlings.Although alpha-diversity of herbs and woody seedlings was not correlated across the site,the local-site contributions to beta-diversity for herbs and woody seedlings were negatively correlated.Habitat type explained slightly more variation in herb community composition than in woody seedling composition,with the highest diversity in the low-elevation slope.Environmental variables explained the variation in species richness and composition more in herbaceous plants than in woody seedlings.Our results indicate that different mechanisms drive variation in the herb and woody seedling communities,with herbs exhibiting greater environmental sensitivity and habitat dependence.These findings contribute to the better understanding of herbaceous plant diversity and composition in forest communities.展开更多
Understanding the underlying processes of how communities are structured remains a central question in community ecology. However, the mechanisms of the soil animal community are still unclear, especially for communit...Understanding the underlying processes of how communities are structured remains a central question in community ecology. However, the mechanisms of the soil animal community are still unclear, especially for communities on a small scale. To evaluate the relative roles of biotic interactions and environmental and spatial processes in a soil collembolan community, a field experiment was carried out on a small scale(50 m) in the farmland ecosystem of the Sanjiang Plain, Northeast China. In August and October, 2011, we took 100 samples each month in a 50 m × 50 m plot using a spatially delimited sampling design. Variation partitioning was used to quantify the relative contributions of the spatial and environmental variables. A null model was selected to test for the non-randomness pattern of species co-occurrence and body size in assemblages of collembolans and to test whether the pattern observed was the result of environmental or biotic processes that structured the community on a small scale. The results showed that large variance was accounted for by spatial variables(18.99% in August and 21.83% in October, both were significant). There were relatively lower effects of environmental variation(3.56% in August and 1.45% in October, neither was significant), while the soil water content, soil p H and soybean height explained a significant portion of the variance that was observed in the spatial pattern of the collembolan community. Furthermore, the null model revealed more co-occurrence than expected by chance, suggesting that collembolan communities had a non-random co-occurrence pattern in both August and October. Additionally, environmental niche overlap and the body size ratio of co-occurrence showed that interspecific competition was not influential in collembolan community structuring. Considering all of the results together, the contributions of spatial and environmental processes were stronger than biotic interactions in the small-scale structuring of a soil collembolan community.展开更多
Latitudinal patterns of treeβ-diversity reveal important insights into the biogeographical processes that influence forest ecosystems.Although previous studies have extensively documentedβ-diversity within relativel...Latitudinal patterns of treeβ-diversity reveal important insights into the biogeographical processes that influence forest ecosystems.Although previous studies have extensively documentedβ-diversity within relatively small spatial extents,the potential drivers ofβ-diversity along latitudinal gradients are still not well understood at larger spatial extents.In this study,we determined whether treeβ-diversity is correlated with latitude in forests of southeastern China,and if so,what ecological processes contribute to these patterns of treeβ-diversity.We specifically aimed to disentangle the relative contributions from interspecific aggregation and environmental filtering across various spatial extents.We delineated regional communities comprising multiple nearby national forest inventory(NFI)plots around random focal plots.The number of NFI plots in a regional community served as a surrogate for spatial extent.We also used a null model to simulate randomly assembled communities and quantify the deviation(β-deviation)between observed and expectedβ-diversity.We found thatβ-diversity decreased along a latitudinal gradient and that this pattern was clearer at larger spatial extents.In addition,latitudinal patterns ofβ-deviation were explained by the degree of species spatial aggregation.We also identified environmental factors that driveβ-deviation in these forests,including precipitation,seasonality,and temperature variation.At larger spatial extents,these environmental variables explained up to 84%of theβ-deviation.Our results reinforce that ecological processes are scale-dependent and collectively contribute to theβ-gradient in subtropical forests.We recommend that conservation efforts maintain diverse forests and heterogeneous environments at multiple spatial extents to mitigate the adverse effects of climate change.展开更多
Mountain systems harbor an evolutionarily unique and exceptionally rich biodiversity,especially for amphibians.However,the associated elevational gradients and underlying mechanisms of amphibian diversity in most moun...Mountain systems harbor an evolutionarily unique and exceptionally rich biodiversity,especially for amphibians.However,the associated elevational gradients and underlying mechanisms of amphibian diversity in most mountain systems remain poorly understood.Here,we explored amphibian phylogenetic and functional diversity along a 2600 m elevational gradient on Mount Emei on the eastern margin of the Qinghai-Tibetan Plateau in southwestern China.We also assessed the relative importance of spatial(area)and environmental factors(temperature,precipitation,solar radiation,normalized difference vegetation index,and potential evapotranspiration)in shaping amphibian distribution and community structure.Results showed that the phylogenetic and functional diversities were unimodal with elevation,while the standardized effect size of phylogenetic and functional diversity increased linearly with elevation.Phylogenetic net relatedness,nearest taxon index,and functional net relatedness index all showed a positive to negative trend with elevation,indicating a shift from clustering to overdispersion and suggesting a potential change in key processes from environmental filtering to competitive exclusion.Overall,our results illustrate the importance of deterministic processes in structuring amphibian communities in subtropical mountains,with the dominant role potentially switching with elevation.This study provides insights into the underlying assembly mechanisms of mountain amphibians,integrating multidimensional diversity.展开更多
Plant communities are shaped by multiple factors along environmental gradients;however,studies are limited on how environmental filtering drives community composition and species richness on tropical inselbergs.We eva...Plant communities are shaped by multiple factors along environmental gradients;however,studies are limited on how environmental filtering drives community composition and species richness on tropical inselbergs.We evaluate the influence of altitude and climatic variables related to temperature and precipitation on plant community composition and species richness on Brazilian inselbergs.We assume as a premise that both climate and altitude would induce changes on plant community composition and species richness at the local level.We used plant inventory data from 370 sampling units across four inselberg sites in the Atlantic Forest of Espírito Santo State,south-eastern Brazil.We tested the univariate and multivariate effects of altitude and climate variables on community composition and species richness with multiple models.Differences in species richness between inselbergs were evaluated using sample-based data to estimate rarefaction and extrapolation curves.In addition,differences in species composition and taxonomic beta diversity were examined via novel frequency-based metrics.A contrasting climate pattern was observed between the inselberg sites,with south sites being wet compared to the dry conditions found in northern sites.Species richness by rarefaction showed a similar pattern within regional sites;however,there were marked differences between regions.Species richness and beta diversity showed significant differences among sites,with higher values in southern sites than in northern sites.In a multi-model comparison between inselberg sites,altitude significantly influenced community composition and species richness and explained more variance than climate models.This finding suggested that climate could act to some extent on these tropical inselbergs;however,altitude was a better predictor of plant community composition and species richness at the local level.展开更多
Functional diversity(FD)reflects within-and between-site variation of species traits(α-and β-FD,respectively).Understanding how much data types(occurrence-based vs.abundance-weighted)and spatial scales(sites vs.regi...Functional diversity(FD)reflects within-and between-site variation of species traits(α-and β-FD,respectively).Understanding how much data types(occurrence-based vs.abundance-weighted)and spatial scales(sites vs.regions)change FD and ultimately interfere with the detection of underlying geoclimatic filters is still debated.To contribute to this debate,we explored the occurrence of 1690 species in 690 sites,abundances of 1198 species in 343 sites,and seven functional traits of the Atlantic Forest woody flora in South America.All FD indices were sensitive and dependent on the data type at both scales,with occurrence particularly increasing a richness and dispersion(occurrence>abundance in 80%of the sites)while abundance increased β total,β replacement,and α evenness(abundance>occurrence in 60%of the sites).Furthermore,detecting the effect of geoclimatic filters depended on the data type and was scale-dependent.At the site scale,precipitation seasonality and soil depth had weak effects on α-and β-FD(max.R^(2)=0.11).However,regional-scale patterns of a richness,dispersion,and evenness strongly mirrored the variation in precipitation seasonality,soil depth,forest stability over the last 120 kyr,and cation exchange capacity(correlations>0.80),suggesting that geoclimatic filters manifest stronger effects at the regional scale.Also,the role of edaphic gradients expands the idea of biogeographical filters beyond climate.Our findings caution functional biogeographic studies to consider the effect of data type and spatial scale before designing and reaching ecological conclusions about the complex nature of FD.展开更多
Geographical background and dispersal ability may strongly influence assemblage dissimilarity;however,these aspects have generally been overlooked in previous large-scale beta diversity studies.Here,we examined whethe...Geographical background and dispersal ability may strongly influence assemblage dissimilarity;however,these aspects have generally been overlooked in previous large-scale beta diversity studies.Here,we examined whether the patterns and drivers of taxonomic beta diversity(TBD)and phylogenetic beta diversity(PBD)of breeding birds in China vary across(1)regions on both sides of the Hu Line,which demarcates China’s topographical,climatic,economic,and social patterns,and(2)species with different dispersal ability.TBD and PBD were calculated and partitioned into turnover and nestedness components using a moving window approach.Variables representing climate,habitat heterogeneity,and habitat quality were employed to evaluate the effects of environmental filtering.Spatial distance was considered to assess the impact of dispersal limitation.Variance partitioning analysis was applied to assess the relative roles of these variables.In general,the values of TBD and PBD were high in mountainous areas and were largely determined by environmental filtering.However,different dominant environmental filters on either side of the Hu Line led to divergent beta diversity patterns.Specifically,climate-driven species turnover and habitat heterogeneity-related species nestedness dominated the regions east and west of the line,respectively.Additionally,bird species with stronger dispersal ability were more susceptible to environmental filtering,resulting in more homogeneous assemblages.Our results indicated that regions with distinctive geographical backgrounds may present different ecological factors that lead to divergent assemblage dissimilarity patterns,and dispersal ability determines the response of assemblages to these ecological factors.Identifying a single universal explanation for the observed pattern without considering these aspects may lead to simplistic or incomplete conclusions.Consequently,a comprehensive understanding of large-scale beta diversity patterns and effective planning of conservation strategies necessitate the consideration of both geographical background and species dispersal ability.展开更多
Biodiversity has been subjected to increasing anthropogenic pressures.It is critical to understand the different processes that govern community assembly and species coexistence under biogeographic processes and anthr...Biodiversity has been subjected to increasing anthropogenic pressures.It is critical to understand the different processes that govern community assembly and species coexistence under biogeographic processes and anthropogenic events.Pheasants(Aves:Phasianidae)are highly threatened birds and China supports the richest pheasant species worldwide.Unravelling the spatial patterns and underlying factors associated with multidimensional biodiversity of species richness(SR),functional diversity(FD),and phylogenetic diversity(PD)of pheasants in China is helpful to understand not only the processes that govern pheasant community assembly and species coexistence,but also pheasant biodiversity conservation.We used a total of 45 pheasant species in China and analyzed the SR,FD,PD,and functional and phylogenetic structures by integrating species distribution maps,functional traits and phylogenies based on 50 km×50 km grid cells.We further used simultaneous autoregressive(SAR)models to explore the factors that determined these patterns.The southern Qinghai-Tibetan Plateau(QTP),Hengduan Mountains,southwestern Mountains,the east of the Qilian Mountains,the Qinling,southern China displayed higher SR,FD,and PD,which were determined by elevation,habitat heterogeneity,temperature seasonality,and vegetation cover.Elevation primarily determined the functional and phylogenetic structures of the pheasant communities.Assemblages in the highlands were marked by functional and phylogenetic clustering,particularly in the QTP,whereas the lowlands in eastern China comprised community overdispersion.Clustered pheasant assemblages were composed of young lineages.Patterns of functional and phylogenetic structures and richness-controlled functional and phylogenetic diversity differed between regions,suggesting that phylogenetic structures are not a good proxy for identifying functional structures.We revealed the significant role of elevation in pheasant community assemblages in China.Highlands interacted with community clustering,whereas lowlands interacted with overdispersion,supporting the environmental filtering hypothesis.Biogeographical drivers other than anthropogenic factor determined biodiversity of pheasants at the present scale of China.This study provides complementary background resources for multi-dimensional pheasant biodiversity and provides insights into avian biodiversity patterns in China.展开更多
Ongoing wind energy developments play a key role in mitigating the global effects of climate change and the energy crisis;however,they have complex ecological consequences for many flying animals.The Yellow Sea coast ...Ongoing wind energy developments play a key role in mitigating the global effects of climate change and the energy crisis;however,they have complex ecological consequences for many flying animals.The Yellow Sea coast is considered as an ecological bottleneck for migratory waterbirds along the East Asian–Australasian flyway(EAAF),and is also an important wind farm base in China.However,the effects of large-scale onshore wind farms along the EAAF on multidimensional waterbird diversity,and how to mitigate these effects,remain unclear.Here we examined how wind farms and their surrounding landscapes affected multidimensional waterbird diversity along the Yellow Sea coast.Taxonomic,functional,and phylogenetic diversity of the waterbird assemblages,and mean pairwise distances and nearest taxon distances with null models were quantified in relation to 4 different wind turbine densities.We also measured 6 landscape variables.Multi-dimensional waterbird diversity(taxonomic,functional,and phylogenetic diversity)significantly decreased with increasing wind turbine density.Functional and phylogenetic structures tended to be clustered in waterbird communities,and environmental filtering drove waterbird community assemblages.Furthermore,waterbird diversity was regulated by a combination of wind turbine density and landscape variables,with edge density of aquaculture ponds,in addition to wind turbine density,having the greatest independent contribution to waterbird diversity.These results suggest that attempts to mitigate the impact of wind farms on waterbird diversity could involve the landscape transformation of wind farm regions,for example,by including high-edge-density aquaculture ponds(i.e.,industrial ponds)around wind farms,instead of traditional low-edge-density aquaculture ponds.展开更多
Mechanisms that drive species co-occurrence are poorly documented for intermittent rivers of semiarid regions. Here, we investigated fish community assembly in response to habitat types and physicochemical conditions ...Mechanisms that drive species co-occurrence are poorly documented for intermittent rivers of semiarid regions. Here, we investigated fish community assembly in response to habitat types and physicochemical conditions in intermittent rivers of the lower Okavango Delta, Botswana. Using Joint Species Distribution Models, we inferred relative influences of environmental filtering and species interactions on patterns of species co-occurrence. Fishes were surveyed from multiple locations during drought and flood phases of the annual hydrological cycle. Species were classified into trophic guilds to facilitate inference about the types of species interactions that influence community structure. Water physicochemistry (depth, temperature, and dissolved oxygen concentration) was significantly associated with species distributions, whereas habitat type (ephemeral vs. permanent) was not significantly associated with species distribution. Controlling for the influence of environmental covariates resulted in three negative residual correlations, of which two involved non-predatory fishes from different trophic guilds, suggesting a behavioral selection of, or enhanced survival within, habitats with different environmental conditions. There was a negative residual correlation between a predator and a potential prey species, suggesting a role for predation mortality or threat in species segregation. Our results demonstrate that using trophic guilds in conjunction with JSDMs can enhance inferences about mechanisms of community assembly.展开更多
To detect the horizontal pattern of phylogenetic structure shown by alpine plants, we measured phylogenetic structure using net related index(NRI) and net nearest taxon index(NTI), and analyzed the phylogenetic struct...To detect the horizontal pattern of phylogenetic structure shown by alpine plants, we measured phylogenetic structure using net related index(NRI) and net nearest taxon index(NTI), and analyzed the phylogenetic structure patterns of alpine plants along longitude, latitude and environmental gradients in the Hengduan Mountains Region(HDMR). Our results show that: 1) the phylogenetic structure tended to cluster with increasing latitude and longitude; 2) for NRI, latitude was closer related than longitude,while for NTI, longitude was closer related than latitude, though they both not significantly relate to NTI.The phylogenetic structure tended towards overdispersion in the southern HDMR, with good climate conditions of higher mean annual temperature and more mean annual precipitation. In contrast, with harsh climate conditions of lower mean annual temperature and less mean annual precipitation, the increasing environmental stress led to phylogenetic clustering in the northern HDMR. The results highlighted that in the alpine region of HDMR, environmental filters and geographical isolation had a great effect on the latitudinal and longitudinal alpine species distribution, respectively.展开更多
Granite-gneiss rock outcrop inselbergs are ancient stable ecosystems with old,climaticallybuffered infertile landscapes(OCBILs).Although inselbergs provide key ecosystem services,little is done for their conservation ...Granite-gneiss rock outcrop inselbergs are ancient stable ecosystems with old,climaticallybuffered infertile landscapes(OCBILs).Although inselbergs provide key ecosystem services,little is done for their conservation and,so far,a lot of their unknown evolutionary history has already been lost by human activities.Using a fine-scale approach,here we tested if habitat and environmental filtering(the inselberg’s harshness)affect the evolutionary diversity of an Atlantic Forest inselberg in Brazil.We recorded all trees with a diameter at breast height≥5cm in 20 plots in four habitat types(total sampled area of 0.8 hectares),from highest to lowest:island,hillside,foothill,and semideciduous forest(matrix).We also collected soil samples for chemical,textural and physical soil characterization.We fitted linear models to test the effects of soil and habitat on plotlevel metrics of phylogenetic diversity and structure,lineage diversity,phylogeneticβ-diversity,and evolutionary distinctiveness.We found that the upper inselberg habitats contain a distinct set of ancient,closely related,harsh-tolerant lineages,as well as a subset of lineages that persist under harsh conditions with a certain degree of water availability.The inferior inselberg habitats harbor higher lineage diversity than expected by chance.Soil strongly predicted evolutionary diversity.We concluded that soil depth,slope,nutrients and texture(environmental filtering)and habitat types and topography(habitat filtering)shape the evolutionary history contained in fine-scale inselberg habitats,which should encourage the conservation of these ancient ecosystems.展开更多
Aims Quantifying the relative importance of the mechanisms that drive community assembly in forests is a crucial issue in community ecol-ogy.The present study aims to understand the ways in which niche-based and spati...Aims Quantifying the relative importance of the mechanisms that drive community assembly in forests is a crucial issue in community ecol-ogy.The present study aims to understand the ways in which niche-based and spatially based processes influence community assembly in areas in different climatic conditions and how these processes change during the transition from seedling to adult.Methods In this study,we investigated how taxonomic and phylogenetic beta diversity in seedling and adult stages of forest trees change across three elevational transects in tropical,subtropical and subalpine for-ests in Southwest China,and the relationships of these changes to the environment and inter-site distances.We quantified the relative contribution of environmental conditions and spatial distribution to taxonomic and phylogenetic beta diversity of both seedling and adult life stages along each elevational transect.We also quantified the taxonomic and phylogenetic similarity between seedlings and adult trees along elevations.Important Findings Taxonomic and phylogenetic beta diversity of both seedlings and adult trees increased with an increase in both environmental distance and spatial distance in all three transects.On both taxonomic and phylo-genetic levels,the effects of environmental filtering and spatial dispos-ition varied between life stages and among forest types.Phylogenetic similarity between seedlings and adult trees increased with elevation,although the taxonomic similarity did not show clear elevational pat-terns.Our results suggest that the relative contribution of niche-based and space-based processes to taxonomic and phylogenetic assem-blages varies across major plant life stages and among forest types.Our findings also highlight the importance of ontogenetic stages for fully understanding community assembly of long-lived tree species.展开更多
基金supported by the National Natural Science Foundation of China(grant number 31901109)Guangdong Basic and Applied Basic Research Foundation(grant number 2021A1515110744).
文摘Understanding how and why assemblage dissimilarity changes along spatial gradient is a great challenge in ecology,because answers to these questions depend on the analytical types,dimensions,and components of beta diversity we concerned.To obtain a comprehensive understanding of assemblage dissimilarity and its implications for biodiversity conservation in the Himalayas,we explored the elevational patterns and determinants of beta diversity and its turnover and nestedness components of pairwise and multiple types and taxonomic and phylogenetic dimensions simultaneously.Patterns of beta diversity and their components of different types and dimensions were calculated based on 96 sampling quadrats along an 1800-5400 m elevational gradient.We examined whether and how these patterns differed from random expectations using null models.Furthermore,we used random forest methods to quantify the role of environmental variables representing climate,topography,and human disturbance in determining these patterns.We found that beta diversity and its turnover component,regardless of its types and dimensions,shown a hump-shaped elevational patterns.Both pairwise and multiple phylogenetic beta diversity were remarkably lower than their taxonomic counterpart.These patterns were significantly less than random expectation and were mostly associated with climate variables.In summary,our results suggested that assemblage dissimilarity of seed plants was mostly originate from the replacement of closely related species determined by climate-driven environmental filtering.Accordingly,conservation efforts should better cover elevations with different climate types to maximalize biodiversity conservation,rather than only focus on elevations with highest species richness.Our study demonstrated that comparisons of beta diversity of different types,dimensions,and components could be conductive to consensus on the origin and mechanism of assemblage dissimilarity.
基金the Botany Graduate Program of Universidade Federal de Vicosa - PPGBot-UFV for the infrastructure and scholarshipsprovided by FAPEMIG (FORTIS/PPGBot-UFV, PPM00584-16, APQ-01309-16)+1 种基金CAPES (PROAP and Pr Int/PPGBot-UFV)CNPq (307591/2016-6, 306335/2020-4)
文摘Global change threatens mountainous plant communities,causing habitat displacement.Phylogenetic studies reveal evolutionary and ecological processes in community assembly.We examined taxonomic and phylogenetic diversity in Andean Páramos across altitudes.Our hypotheses were that increasing altitude is an environmental filter,as altitude is expected to be a stronger variable than soil depth.The Páramos,alpine vegetation in the Andes,range from 3,000 to 4,700 meters,with our plots spanning 3,200 to 4,100 meters.Sampling was conducted at six altitudinal levels,measuring soil depth,taxonomic,and phylogenetic diversity.Data analysis employed multiple linear regressions and mixed-effects models to assess the effects of soil depth and altitude.We sampled 110 angiosperm species from 70 genera,30 families,and 18 orders.Asterales and Poales were prominent.Species richness generally decreased with altitude but increased at the summit.Soil depth affected species richness and taxonomic diversity,while altitude did not.Phylogenetic diversity increased with soil depth and decreased with altitude.Phylogenetic turnover increased with altitude differences.The hypothesis that increasing altitude intensifies environmental filtering in the altitudeadapted Páramos resulting in lower species richness and more clustered phylogenetic structures,was rejected.Although species richness,Shannon diversity,and Simpson diversity decreased initially with increasing altitude,this trend was not linear because the summit presented intermediate species richness.The hypothesis that altitude is a stronger explanatory variable than soil depth was also rejected.Despite expectations,taxonomic results did not support altitude as an environmental filter,but soil depth.Greater altitude differences increased beta phylogenetic dissimilarity,supporting niche conservatism.
基金provided by FAPEMIG(FORTIS/PPGBot-UFV,PPM-00584-16,APQ‐01309‐16)CAPES(PROAP and PrInt/PPGBot-UFV),CNPq(307591/2016‐6,306335/2020-4).
文摘Elucidating how multiple factors affect biodiversity and plant community assembly is a central issue in ecology,especially in vulnerable ecosystems such as tropical mountains.These studies are more relevant in global warming scenarios that induce the upward displacement of plant species towards reduced habitats and hostile environments in tropical mountains.This study aimed to analyze how altitude affects taxonomic and phylogenetic diversity in plant communities of tropical mountains.Thus,we tested if(i)increased altitude works as an environmental filtering promoting decreased species richness,decreased phylogenetic diversity,and increased phylogenetic clustering in these tropical mountains;and if(ii)plant communities of high altitude in tropical mountains are also result of recent diversification with plant species recently split shortening phylogenetic distances between closest related species.We tested effects of altitude on species richness and phylogenetic metrics using linear mixed-effects models.Mount Haleakala presented 114 species,Mount Kilimanjaro presented 231 species and Mount Purace presented 280 species.We found an environmental filtering effect with increasing altitude causing phylogenetic clustering,decreased phylogenetic diversity and decreased species richness.The decreasing phylogenetic distances between closest relatives are congruent with neo-endemics,suggesting recent plant diversification in high altitudes of tropical mountains,possibly driven by geographic isolation and environmental heterogeneity.Consequences of global warming should be monitored in tropical mountains focusing on distribution shifts.
基金financially supported by the National Natural Science Foundation of China (41461046,31760707)
文摘Grazing exclusion is one of the most efficient approaches to restore degraded grassland but may negatively affects the recovery of species diversity. Changes in plant species diversity should be a consequence of the ecological assembly process. Local community assembly is influenced by environmental filtering, biotic interactions, and dispersal. However, how these factors potentially contribute to changes to species diversity is poorly understood, especially in harsh environments. In this study, two management sites within a Stipa breviflora desert steppe community（typical natural steppe） were selected in northern China. In one of the two management sites, grazing has been excluded since 2010 and in the other with open grazing by sheep. In August 2016, three plots were established and 100 sampling units were created within each plot in a 5 m×5 m area at the two management sites. To assess the effects of grazing exclusion on S. breviflora steppe, we analyzed the vegetation biomass, species diversity,soil organic carbon, and soil particle size distribution using paired T-tests. In addition, variation partitioning was applied to determine the relative importance of environmental filtering and dispersal limitation. Null mode analysis was used to quantify the influence of biotic interactions in conjunction with Eco Sim niche overlap and co-occurrence values. Our results demonstrated that（1） species diversity significantly decreased and the main improvements in soil quality occurred in the topsoil 0–10 cm after the grazing exclusion;（2） environmental filtering was important for community assembly between grazed and fenced grassland and this appears particularly true for soil particle size distribution, which may be well correlated with soil hydrological processes; and（3） however, competitive exclusion may play a significant role within the exclusion. The multiple pathways of assembly may collectively determine negative effects on the restoration of species diversity. Therefore, designers should be aware of the risk of reducing grazing exclusion-induced species diversity and account for manipulating processes. This in turn will reduce dominant species and promote environmental heterogeneity to maximize species diversity in semi-arid regions.
基金supported by the program“Shenzhen City under the grant of Aquatic Ecological Monitoring and Assessment for Major rivers”(No.2019-07-233)Special Foundation for National Science and Technology Basic Research Program of China(grant No.2019FY101903).
文摘Background:Disentangling the relative roles of environmental filtering and spatial processes in structuring ecological communities is a central topic in metacommunity ecology.Metacommunity ecology in the temperate river ecosystems has been well developed,while less attention has been paid to subtropical urban river networks.Here,we examined the ecological factors and seasonal difference in structuring macroinvertebrates metacommunity assembly in the subtropical urban river networks in Shenzhen,South China.Results:Our results revealed that there was no significant distinction of macroinvertebrate community composition among seasons,with only the relative abundance of Mollusca and Odonata significantly differed in both wet and dry seasons.One possible explanation was that most macroinvertebrates are generally pollution-tolerant taxa characterized with nonseasonal life cycle.In addition,distance-based redundancy analysis and variation partitioning approach revealed that metacommunity was determined equally by the environmental and dispersal-related factors.Further,our results showed that,although a slight temporal variation of relative contribution,the identity and explanation power of ecological factors were different among seasons.Specifically,stronger environmental filtering structuring community dynamics was observed in the dry than wet seasons,which might be owing to higher environmental heterogeneity under a low water-flow condition.Moreover,we detected that the influence of spatial processes was stronger in the wet than dry seasons,indicating an obvious dispersal processes due to high connectivity among sites.Conclusion:Overall,our results revealed that environmental and spatial factors equally explained variations of macroinvertebrate metacommunity,implying the necessity of considering dispersal-related processes structuring ecological communities in river bioassessment programs.Moreover,degraded habitat conditions and water quality were the predominant factors that affected macroinvertebrate communities,indicating the significance and feasibility of improving local abiotic conditions to sustain local biodiversity.Further,our findings revealed the importance of seasonal dynamics of these urban river networks in structuring macroinvertebrate metacommunity.Thereby,our study improves the understanding of ecological processes governing macroinvertebrate metacommunity and underlines the idea that community ecology studies should go beyond the single snapshot survey in river networks.
基金financially supported by the NSF of China(3227161431870408)+3 种基金Biological Resources Programme,Chinese Academy of SciencesState Key Laboratory of Vegetation and Environmental Change of China(Y7206F1016)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31030000)National key basic R&D program of China(2017YFA0605100).
文摘Herbaceous plants are an essential component of forest diversity and driver of ecosystem processes.However,because the growth forms and life-history strategies of herbaceous plants differ from those of woody plants,it is unclear whether the mechanisms that drive patterns plant diversity and community structure in these two plant groups are the same.In this study,we determined whether herb and woody plant communities have similar patterns and drivers of alpha-and beta-diversity.We compared species richness,distribution,and abundance of herbs to woody seedlings in a 20-ha Donglingshan warmtemperate forest(Donglingshan FDP),China.We also determined whether variation in patterns of species richness and composition are better explained by environmental or spatial variables.Herbaceous plants accounted for 72%of all species(81 herbaceous,31 woody)recorded.Alpha-and beta-diversity were higher in herbs than in woody seedlings.Although alpha-diversity of herbs and woody seedlings was not correlated across the site,the local-site contributions to beta-diversity for herbs and woody seedlings were negatively correlated.Habitat type explained slightly more variation in herb community composition than in woody seedling composition,with the highest diversity in the low-elevation slope.Environmental variables explained the variation in species richness and composition more in herbaceous plants than in woody seedlings.Our results indicate that different mechanisms drive variation in the herb and woody seedling communities,with herbs exhibiting greater environmental sensitivity and habitat dependence.These findings contribute to the better understanding of herbaceous plant diversity and composition in forest communities.
基金Under the auspices of National Natural Science Foundation of China(No.41101049,41471037,41371072,41430857)University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2015054)+1 种基金Distinguished Young Scholar of Harbin Normal University(No.KGB201204)Excellent Youth Scholars of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.DLSYQ13003)
文摘Understanding the underlying processes of how communities are structured remains a central question in community ecology. However, the mechanisms of the soil animal community are still unclear, especially for communities on a small scale. To evaluate the relative roles of biotic interactions and environmental and spatial processes in a soil collembolan community, a field experiment was carried out on a small scale(50 m) in the farmland ecosystem of the Sanjiang Plain, Northeast China. In August and October, 2011, we took 100 samples each month in a 50 m × 50 m plot using a spatially delimited sampling design. Variation partitioning was used to quantify the relative contributions of the spatial and environmental variables. A null model was selected to test for the non-randomness pattern of species co-occurrence and body size in assemblages of collembolans and to test whether the pattern observed was the result of environmental or biotic processes that structured the community on a small scale. The results showed that large variance was accounted for by spatial variables(18.99% in August and 21.83% in October, both were significant). There were relatively lower effects of environmental variation(3.56% in August and 1.45% in October, neither was significant), while the soil water content, soil p H and soybean height explained a significant portion of the variance that was observed in the spatial pattern of the collembolan community. Furthermore, the null model revealed more co-occurrence than expected by chance, suggesting that collembolan communities had a non-random co-occurrence pattern in both August and October. Additionally, environmental niche overlap and the body size ratio of co-occurrence showed that interspecific competition was not influential in collembolan community structuring. Considering all of the results together, the contributions of spatial and environmental processes were stronger than biotic interactions in the small-scale structuring of a soil collembolan community.
基金supported by the National Natural Science Foundation of China(42271317)the Innovation Research Team Project of the Natural Science Foundation of Hainan Province(422CXTD515)。
文摘Latitudinal patterns of treeβ-diversity reveal important insights into the biogeographical processes that influence forest ecosystems.Although previous studies have extensively documentedβ-diversity within relatively small spatial extents,the potential drivers ofβ-diversity along latitudinal gradients are still not well understood at larger spatial extents.In this study,we determined whether treeβ-diversity is correlated with latitude in forests of southeastern China,and if so,what ecological processes contribute to these patterns of treeβ-diversity.We specifically aimed to disentangle the relative contributions from interspecific aggregation and environmental filtering across various spatial extents.We delineated regional communities comprising multiple nearby national forest inventory(NFI)plots around random focal plots.The number of NFI plots in a regional community served as a surrogate for spatial extent.We also used a null model to simulate randomly assembled communities and quantify the deviation(β-deviation)between observed and expectedβ-diversity.We found thatβ-diversity decreased along a latitudinal gradient and that this pattern was clearer at larger spatial extents.In addition,latitudinal patterns ofβ-deviation were explained by the degree of species spatial aggregation.We also identified environmental factors that driveβ-deviation in these forests,including precipitation,seasonality,and temperature variation.At larger spatial extents,these environmental variables explained up to 84%of theβ-deviation.Our results reinforce that ecological processes are scale-dependent and collectively contribute to theβ-gradient in subtropical forests.We recommend that conservation efforts maintain diverse forests and heterogeneous environments at multiple spatial extents to mitigate the adverse effects of climate change.
基金supported by the National Natural Science Foundation of China(31770568,32071544)Natural Science Foundation of Shanghai(20ZR1418100)“Light of West China”Program of the Chinese Academy of Sciences。
文摘Mountain systems harbor an evolutionarily unique and exceptionally rich biodiversity,especially for amphibians.However,the associated elevational gradients and underlying mechanisms of amphibian diversity in most mountain systems remain poorly understood.Here,we explored amphibian phylogenetic and functional diversity along a 2600 m elevational gradient on Mount Emei on the eastern margin of the Qinghai-Tibetan Plateau in southwestern China.We also assessed the relative importance of spatial(area)and environmental factors(temperature,precipitation,solar radiation,normalized difference vegetation index,and potential evapotranspiration)in shaping amphibian distribution and community structure.Results showed that the phylogenetic and functional diversities were unimodal with elevation,while the standardized effect size of phylogenetic and functional diversity increased linearly with elevation.Phylogenetic net relatedness,nearest taxon index,and functional net relatedness index all showed a positive to negative trend with elevation,indicating a shift from clustering to overdispersion and suggesting a potential change in key processes from environmental filtering to competitive exclusion.Overall,our results illustrate the importance of deterministic processes in structuring amphibian communities in subtropical mountains,with the dominant role potentially switching with elevation.This study provides insights into the underlying assembly mechanisms of mountain amphibians,integrating multidimensional diversity.
文摘Plant communities are shaped by multiple factors along environmental gradients;however,studies are limited on how environmental filtering drives community composition and species richness on tropical inselbergs.We evaluate the influence of altitude and climatic variables related to temperature and precipitation on plant community composition and species richness on Brazilian inselbergs.We assume as a premise that both climate and altitude would induce changes on plant community composition and species richness at the local level.We used plant inventory data from 370 sampling units across four inselberg sites in the Atlantic Forest of Espírito Santo State,south-eastern Brazil.We tested the univariate and multivariate effects of altitude and climate variables on community composition and species richness with multiple models.Differences in species richness between inselbergs were evaluated using sample-based data to estimate rarefaction and extrapolation curves.In addition,differences in species composition and taxonomic beta diversity were examined via novel frequency-based metrics.A contrasting climate pattern was observed between the inselberg sites,with south sites being wet compared to the dry conditions found in northern sites.Species richness by rarefaction showed a similar pattern within regional sites;however,there were marked differences between regions.Species richness and beta diversity showed significant differences among sites,with higher values in southern sites than in northern sites.In a multi-model comparison between inselberg sites,altitude significantly influenced community composition and species richness and explained more variance than climate models.This finding suggested that climate could act to some extent on these tropical inselbergs;however,altitude was a better predictor of plant community composition and species richness at the local level.
基金supported by FAPERJ-Fundação Carlos Chagas Filho de AmparoàPesquisa do Estado do Rio de Janeiro through a post-doctoral fellowship and scientific grant for JoséLuiz Alves Silva[E-26/204.257/2021]by CNPq-Conselho Nacional de Desenvolvimento Científico e Tecnológico through a grant for Angela Pierre Vitória[n°302325/2022-0].
文摘Functional diversity(FD)reflects within-and between-site variation of species traits(α-and β-FD,respectively).Understanding how much data types(occurrence-based vs.abundance-weighted)and spatial scales(sites vs.regions)change FD and ultimately interfere with the detection of underlying geoclimatic filters is still debated.To contribute to this debate,we explored the occurrence of 1690 species in 690 sites,abundances of 1198 species in 343 sites,and seven functional traits of the Atlantic Forest woody flora in South America.All FD indices were sensitive and dependent on the data type at both scales,with occurrence particularly increasing a richness and dispersion(occurrence>abundance in 80%of the sites)while abundance increased β total,β replacement,and α evenness(abundance>occurrence in 60%of the sites).Furthermore,detecting the effect of geoclimatic filters depended on the data type and was scale-dependent.At the site scale,precipitation seasonality and soil depth had weak effects on α-and β-FD(max.R^(2)=0.11).However,regional-scale patterns of a richness,dispersion,and evenness strongly mirrored the variation in precipitation seasonality,soil depth,forest stability over the last 120 kyr,and cation exchange capacity(correlations>0.80),suggesting that geoclimatic filters manifest stronger effects at the regional scale.Also,the role of edaphic gradients expands the idea of biogeographical filters beyond climate.Our findings caution functional biogeographic studies to consider the effect of data type and spatial scale before designing and reaching ecological conclusions about the complex nature of FD.
基金supported by the National Natural Science Foundation of China(31901220)Science and Technology Planning Project of Guangdong Province,China(2019B121202004)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2021A1515110744)Forestry Administration of Guangdong Province(DFGP Project of Fauna of Guangdong-202115)。
文摘Geographical background and dispersal ability may strongly influence assemblage dissimilarity;however,these aspects have generally been overlooked in previous large-scale beta diversity studies.Here,we examined whether the patterns and drivers of taxonomic beta diversity(TBD)and phylogenetic beta diversity(PBD)of breeding birds in China vary across(1)regions on both sides of the Hu Line,which demarcates China’s topographical,climatic,economic,and social patterns,and(2)species with different dispersal ability.TBD and PBD were calculated and partitioned into turnover and nestedness components using a moving window approach.Variables representing climate,habitat heterogeneity,and habitat quality were employed to evaluate the effects of environmental filtering.Spatial distance was considered to assess the impact of dispersal limitation.Variance partitioning analysis was applied to assess the relative roles of these variables.In general,the values of TBD and PBD were high in mountainous areas and were largely determined by environmental filtering.However,different dominant environmental filters on either side of the Hu Line led to divergent beta diversity patterns.Specifically,climate-driven species turnover and habitat heterogeneity-related species nestedness dominated the regions east and west of the line,respectively.Additionally,bird species with stronger dispersal ability were more susceptible to environmental filtering,resulting in more homogeneous assemblages.Our results indicated that regions with distinctive geographical backgrounds may present different ecological factors that lead to divergent assemblage dissimilarity patterns,and dispersal ability determines the response of assemblages to these ecological factors.Identifying a single universal explanation for the observed pattern without considering these aspects may lead to simplistic or incomplete conclusions.Consequently,a comprehensive understanding of large-scale beta diversity patterns and effective planning of conservation strategies necessitate the consideration of both geographical background and species dispersal ability.
基金supported by grants from the National Natural Science Foundation of China(No.31872240)the National Key R&D Plan Project(No.2016YFC0503206)。
文摘Biodiversity has been subjected to increasing anthropogenic pressures.It is critical to understand the different processes that govern community assembly and species coexistence under biogeographic processes and anthropogenic events.Pheasants(Aves:Phasianidae)are highly threatened birds and China supports the richest pheasant species worldwide.Unravelling the spatial patterns and underlying factors associated with multidimensional biodiversity of species richness(SR),functional diversity(FD),and phylogenetic diversity(PD)of pheasants in China is helpful to understand not only the processes that govern pheasant community assembly and species coexistence,but also pheasant biodiversity conservation.We used a total of 45 pheasant species in China and analyzed the SR,FD,PD,and functional and phylogenetic structures by integrating species distribution maps,functional traits and phylogenies based on 50 km×50 km grid cells.We further used simultaneous autoregressive(SAR)models to explore the factors that determined these patterns.The southern Qinghai-Tibetan Plateau(QTP),Hengduan Mountains,southwestern Mountains,the east of the Qilian Mountains,the Qinling,southern China displayed higher SR,FD,and PD,which were determined by elevation,habitat heterogeneity,temperature seasonality,and vegetation cover.Elevation primarily determined the functional and phylogenetic structures of the pheasant communities.Assemblages in the highlands were marked by functional and phylogenetic clustering,particularly in the QTP,whereas the lowlands in eastern China comprised community overdispersion.Clustered pheasant assemblages were composed of young lineages.Patterns of functional and phylogenetic structures and richness-controlled functional and phylogenetic diversity differed between regions,suggesting that phylogenetic structures are not a good proxy for identifying functional structures.We revealed the significant role of elevation in pheasant community assemblages in China.Highlands interacted with community clustering,whereas lowlands interacted with overdispersion,supporting the environmental filtering hypothesis.Biogeographical drivers other than anthropogenic factor determined biodiversity of pheasants at the present scale of China.This study provides complementary background resources for multi-dimensional pheasant biodiversity and provides insights into avian biodiversity patterns in China.
基金fnancially supported by the Science and Technology Commission of Shanghai Municipality(No.18DZ1205000)Natural Science Foundation of China(No.31901099)+3 种基金Yangtze Delta Estuarine Wetland Ecosystem Observation and Research Station,Ministry of Education,Shanghai Science and Technology Committee(ECNU-YDEWS-2022)Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering,Institute of Biodiversity Science,Fudan University(2023-FDU-KF-02)Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration(SHUES2023A04)“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2024C02002).
文摘Ongoing wind energy developments play a key role in mitigating the global effects of climate change and the energy crisis;however,they have complex ecological consequences for many flying animals.The Yellow Sea coast is considered as an ecological bottleneck for migratory waterbirds along the East Asian–Australasian flyway(EAAF),and is also an important wind farm base in China.However,the effects of large-scale onshore wind farms along the EAAF on multidimensional waterbird diversity,and how to mitigate these effects,remain unclear.Here we examined how wind farms and their surrounding landscapes affected multidimensional waterbird diversity along the Yellow Sea coast.Taxonomic,functional,and phylogenetic diversity of the waterbird assemblages,and mean pairwise distances and nearest taxon distances with null models were quantified in relation to 4 different wind turbine densities.We also measured 6 landscape variables.Multi-dimensional waterbird diversity(taxonomic,functional,and phylogenetic diversity)significantly decreased with increasing wind turbine density.Functional and phylogenetic structures tended to be clustered in waterbird communities,and environmental filtering drove waterbird community assemblages.Furthermore,waterbird diversity was regulated by a combination of wind turbine density and landscape variables,with edge density of aquaculture ponds,in addition to wind turbine density,having the greatest independent contribution to waterbird diversity.These results suggest that attempts to mitigate the impact of wind farms on waterbird diversity could involve the landscape transformation of wind farm regions,for example,by including high-edge-density aquaculture ponds(i.e.,industrial ponds)around wind farms,instead of traditional low-edge-density aquaculture ponds.
文摘Mechanisms that drive species co-occurrence are poorly documented for intermittent rivers of semiarid regions. Here, we investigated fish community assembly in response to habitat types and physicochemical conditions in intermittent rivers of the lower Okavango Delta, Botswana. Using Joint Species Distribution Models, we inferred relative influences of environmental filtering and species interactions on patterns of species co-occurrence. Fishes were surveyed from multiple locations during drought and flood phases of the annual hydrological cycle. Species were classified into trophic guilds to facilitate inference about the types of species interactions that influence community structure. Water physicochemistry (depth, temperature, and dissolved oxygen concentration) was significantly associated with species distributions, whereas habitat type (ephemeral vs. permanent) was not significantly associated with species distribution. Controlling for the influence of environmental covariates resulted in three negative residual correlations, of which two involved non-predatory fishes from different trophic guilds, suggesting a behavioral selection of, or enhanced survival within, habitats with different environmental conditions. There was a negative residual correlation between a predator and a potential prey species, suggesting a role for predation mortality or threat in species segregation. Our results demonstrate that using trophic guilds in conjunction with JSDMs can enhance inferences about mechanisms of community assembly.
基金supported by Major Program of National Natural Science Foundation of China grant no. 31590823 to Hang Sunthe National Natural Science Foundation of China (NSFC) Grant No. 31560063Key Disciplines (Ecology) Project of Yunnan Education Department
文摘To detect the horizontal pattern of phylogenetic structure shown by alpine plants, we measured phylogenetic structure using net related index(NRI) and net nearest taxon index(NTI), and analyzed the phylogenetic structure patterns of alpine plants along longitude, latitude and environmental gradients in the Hengduan Mountains Region(HDMR). Our results show that: 1) the phylogenetic structure tended to cluster with increasing latitude and longitude; 2) for NRI, latitude was closer related than longitude,while for NTI, longitude was closer related than latitude, though they both not significantly relate to NTI.The phylogenetic structure tended towards overdispersion in the southern HDMR, with good climate conditions of higher mean annual temperature and more mean annual precipitation. In contrast, with harsh climate conditions of lower mean annual temperature and less mean annual precipitation, the increasing environmental stress led to phylogenetic clustering in the northern HDMR. The results highlighted that in the alpine region of HDMR, environmental filters and geographical isolation had a great effect on the latitudinal and longitudinal alpine species distribution, respectively.
基金Coordination for the Improvement of Higher Education Personnel(CAPES)the National Council for Scientific and Technological Development(CNPq)the Minas Gerais State Research Foundation(FAPEMIG)for research funding and scholarships to the authors。
文摘Granite-gneiss rock outcrop inselbergs are ancient stable ecosystems with old,climaticallybuffered infertile landscapes(OCBILs).Although inselbergs provide key ecosystem services,little is done for their conservation and,so far,a lot of their unknown evolutionary history has already been lost by human activities.Using a fine-scale approach,here we tested if habitat and environmental filtering(the inselberg’s harshness)affect the evolutionary diversity of an Atlantic Forest inselberg in Brazil.We recorded all trees with a diameter at breast height≥5cm in 20 plots in four habitat types(total sampled area of 0.8 hectares),from highest to lowest:island,hillside,foothill,and semideciduous forest(matrix).We also collected soil samples for chemical,textural and physical soil characterization.We fitted linear models to test the effects of soil and habitat on plotlevel metrics of phylogenetic diversity and structure,lineage diversity,phylogeneticβ-diversity,and evolutionary distinctiveness.We found that the upper inselberg habitats contain a distinct set of ancient,closely related,harsh-tolerant lineages,as well as a subset of lineages that persist under harsh conditions with a certain degree of water availability.The inferior inselberg habitats harbor higher lineage diversity than expected by chance.Soil strongly predicted evolutionary diversity.We concluded that soil depth,slope,nutrients and texture(environmental filtering)and habitat types and topography(habitat filtering)shape the evolutionary history contained in fine-scale inselberg habitats,which should encourage the conservation of these ancient ecosystems.
基金This research was supported by the National Natural Science Foundation of China(31400362 and 31670442)National Key Basic Research Program of China(2014CB954100)+2 种基金the West Light Foundation of the Chinese Academy of Sciences,the Chinese Academy of Sciences Youth Innovation Promotion Association(2016352)the Queensland-Chinese Academy of Sciences Biotechnology Fund(GJHZ1130)the Applied Fundamental Research Foundation of Yunnan Province(2014GA003 and 2013FB079).
文摘Aims Quantifying the relative importance of the mechanisms that drive community assembly in forests is a crucial issue in community ecol-ogy.The present study aims to understand the ways in which niche-based and spatially based processes influence community assembly in areas in different climatic conditions and how these processes change during the transition from seedling to adult.Methods In this study,we investigated how taxonomic and phylogenetic beta diversity in seedling and adult stages of forest trees change across three elevational transects in tropical,subtropical and subalpine for-ests in Southwest China,and the relationships of these changes to the environment and inter-site distances.We quantified the relative contribution of environmental conditions and spatial distribution to taxonomic and phylogenetic beta diversity of both seedling and adult life stages along each elevational transect.We also quantified the taxonomic and phylogenetic similarity between seedlings and adult trees along elevations.Important Findings Taxonomic and phylogenetic beta diversity of both seedlings and adult trees increased with an increase in both environmental distance and spatial distance in all three transects.On both taxonomic and phylo-genetic levels,the effects of environmental filtering and spatial dispos-ition varied between life stages and among forest types.Phylogenetic similarity between seedlings and adult trees increased with elevation,although the taxonomic similarity did not show clear elevational pat-terns.Our results suggest that the relative contribution of niche-based and space-based processes to taxonomic and phylogenetic assem-blages varies across major plant life stages and among forest types.Our findings also highlight the importance of ontogenetic stages for fully understanding community assembly of long-lived tree species.
