Background Ecosystem services(ESs)are fundamental to ensuring human well-being and sustainable development.However,the complex nonlinear relationships between ESs and social systems are still not fully recognized at p...Background Ecosystem services(ESs)are fundamental to ensuring human well-being and sustainable development.However,the complex nonlinear relationships between ESs and social systems are still not fully recognized at present.Here,we used a comprehensive indicator framework,a coupling coordination degree(CCD)model,and a GeoDetector model to measure the CCD and development level of ESs and social systems in Sanmenxia City,Henan Province,China from 2000 to 2020,analyze the spatial patterns and temporal variations of their development,and quantify the influence of 15 factors on the spatial heterogeneity of their CCD.Results We observed that the increase of social system development level in Sanmenxia City was higher than that of ESs'provisioning capacity.From 2000 to 2020,the ecosystem service index value of Sanmenxia City increased by about 25%,while the level of social system development increased by 118.9%.The coordination between ESs and social systems improved by 25%,indicating that their relationships were shifting from trade-offs to synergies.Lushi County(one of the six administrative regions of Sanmenxia City)had the highest level of CCD,but the overall coordination remained relatively weak in Sanmenxia City,and none of the six administrative regions achieved a high level of coordination.CCD was influenced by multiple interacting factors,with topography and land use patterns being the primary drivers.Conclusions Optimizing the spatial layout of ecological space,agricultural space,and urban space based on natural geographic patterns can be an effective way to improve CCD.Accordingly,we identified the impacts of potential barriers on sustainable development and provided multiple possible effective actions.Our findings deepen the knowledge and understanding of the“human-nature relationships”,which are of great significance in promoting the synergistic development of social and ecological systems.展开更多
Background The temperate grasslands are facing numerous pressures from global change.Despite their essential ecological and economic role,how their microbial communities react to multiple varying factors remain obscur...Background The temperate grasslands are facing numerous pressures from global change.Despite their essential ecological and economic role,how their microbial communities react to multiple varying factors remain obscure.In this study,we simulated three global change drivers,i.e.,nitrogen deposition(ambient N vs.elevated N,a N vs.e N),precipitation increase(ambient precipitation vs.elevated precipitation,a P vs.e P),and mowing,represented experimentally by clipping(unclipped vs.clipped,u C vs.CL),together in all possible combinations in a temperate semi-arid grassland ecosystem.Results Nitrogen addition had negative effects on the richness of bacterial and fungal communties,significantly changed their structures(P<0.05)and increased their dissimilarities(P<0.05),while water addition had positive effects on fungal and protist communities and significantly stimulated theα-diversity of protist communities under N addition without clipping,which was in contrast to the effect in clipped plots.Clipping had a marginal effect on fungal communities and significantly affected protist communities(P<0.05).A notable interactive effect of N and precipitation on the structure of bacterial communities and a significant interactive effect of clipping and precipitation on protists were found.Combination effects of N with precipitation or clipping on module aggregation of metanetworks were also observed between u C and CL,as well as a P and e P meta-networks.Bacterial,fungal,and protist communities varied in their assembly mechanisms,and their assembly processes differed in response to the three global change factors.Conclusions Overall,N,water addition,and clipping individually and/or interactively,in distinct degrees,altered soil microbial interaction,community structure,and the potential function in a semi-arid steppe.These findings enhance our understanding of soil microbial community assembly and provide a scientific basis for managing temperate grasslands,particularly in the context of global change's impact on ecosystem function and stability.展开更多
Background The forest floor humus layer is an important carbon pool and serves as a key interface that influences forest soil carbon and nutrient cycling,especially in temperate and boreal forests.Over the past decade...Background The forest floor humus layer is an important carbon pool and serves as a key interface that influences forest soil carbon and nutrient cycling,especially in temperate and boreal forests.Over the past decades,China has implemented numerous forestry ecological programs,leading to an increasing quantity of forest floor litter and the formation of humus layers,which has altered the interface between aboveground litter and surface soil.Our previous study revealed that these alterations affect the litter decomposition rate;however,it is still unclear how the litter decomposition process changes,how nutrients are released or imported and the extent to which these changes depend on the humus layer.Results In this study,we used a 535-day in situ litterbag experiment to monitor the litter decomposition process and nutrient variations under forest floor humus layer removal in a Pinus sylvestris var.mongolica plantation in Northeast China.The results revealed that the litter decomposed quickly when a forest floor humus layer was present,with the decomposition rate constant(k value)increasing from 0.122 to 0.328.Accordingly,during decomposition,the litter C,N and P concentrations increased,whereas their contents varied only slightly(with the exception of the litter P content,which decreased significantly)compared with those in the treatment where the humus layer was removed.However,both the litter C and N contents decreased,whereas the litter P content increased significantly compared with the initial litter content.Moreover,the litter C:N,C:P and N:P ratios decreased significantly during decomposition.In addition,the microbial community diversity of the litter showed no significant change,whereas the relative abundances of several major fungal and bacterial taxa at the phylum and genus levels varied significantly.Furthermore,redundancy analysis revealed effective relationships among the k values,chemical traits and microbial communities,and the least squares method suggested that the C,P and C:P ratios of the litter were significantly correlated with the litter decomposition rate.Conclusions These results enhance our understanding of the role of the humus layer in forest soil-plant carbon and nutrient cycling and should be considered in carbon cycle models in the future.展开更多
Background The mangrove ecosystem has the highest carbon sink potential which significantly contributes to bringing carbon neutrality.Understanding the carbon stock dynamics along the age of forest stands in the mangr...Background The mangrove ecosystem has the highest carbon sink potential which significantly contributes to bringing carbon neutrality.Understanding the carbon stock dynamics along the age of forest stands in the mangrove forest ecosystem is of significance for managing the forests and their carbon accumulation.This study aimed to estimate the forest structural attributes,biomass and total ecosystem carbon stock(TECS)of old natural(age>50 years)and young planted(age~20 years)mangrove forest stands at Bichitrapur Mangrove Reserve Forest in eastern coast of India.We also attempted to understand the interrelationship of structural attributes,biomass and soil properties in the mangrove forests.To achieve the results,twenty random plots were established(size:20 m×25 m)and suitable allometric equations along with species-specific wood density values were used to estimate the biomass and carbon stock.Results Altogether,29 plant species(18 exclusive and 11 associate species)were recorded.The mean total biomass(±SE)and soil organic carbon(at 30 cm depth)were 165.31±20.89 t ha^(-1)and 40.20±1.24 t C ha^(-1)for young stands,and 586.12±56.74 t ha^(-1)and 49.68±2.39 t C ha^(-1)for old stands,respectively.Among mangrove species,Avicennia marina contributed the highest vegetation biomass in both forest stands(59.72 t ha^(-1)and 262.28 t ha^(-1)in young and old stands,respectively),followed by Avicennia officinalis(35.05 t ha^(-1))and Sonneratia apetala(26.09 t ha^(-1))in young stand and Avicennia alba(169.28 t ha^(-1))and Avicennia officinalis(115.58 t ha^(-1))in old stand.The mean TECS was 235.62±27.34 t C ha^(-1).The contribution of vegetation and soil to TECS was 63%and 37%in the young stand,whereas in the old stand it was 83%and 17%,respectively.The correlation analyses revealed that mean stand height(r=0.87),basal area(r=0.99),soil nitrogen(r=0.76),potassium(r=0.78),and carbon(r=0.80)were significantly positively correlated with total biomass at p<0.01.Conclusions Our results demonstrate that old mangrove forest stands store substantially high carbon stock than young planted forest stands,implying the role of forest age in determining the carbon storage potential of mangrove ecosystems.展开更多
Background The effects of war on biodiversity,habitats,ecosystem services,and water,seafood,and fishing resources are complex and long-lasting,yet their ongoing environmental analyses are limited.The Russia–Ukraine W...Background The effects of war on biodiversity,habitats,ecosystem services,and water,seafood,and fishing resources are complex and long-lasting,yet their ongoing environmental analyses are limited.The Russia–Ukraine War(2022–present)comprises a unique ecological situation to examine biodiversity effects on the distinctive cold-temperate northern Black Sea ecosystem,which has an intriguing biogeographic history and high endemism resulting from geographic isolation and differentiation.Results We summarize negative and positive effects from the War on the aquatic(marine,estuarine,and freshwater)biota and their habitats,focusing on investigations by the Institute of Marine Biology,National Academy of Sciences of Ukraine.Negative effects include toxins and habitat damage from oil spills,shelling,mining,explosions,flooding,and fires;along with disregard of Protected Areas.Positive effects are reduced anthropogenic loads from less shipping,fishing,trawling,recreation,hydraulic engineering,construction,and tourism.The Kakhovka Dam's destruction on June 6,2023 was the greatest ecological catastrophe to date,causing extensive downstream flooding with freshwaters and pollutants that destroyed many populations and habitats.We discern that many effects have been temporary,with habitats and species replenishing,and some reverting to their historical biota characteristic of lower salinity regimes.However,significant habitat destruction,disturbances,and pollutant damages remain.Since many of the native species evolved in conditions favoring broad salinity,temperature,and oxygen tolerances,the northern Black Sea ecosystem appears pre-adapted for ecological recovery and persistence,which may equate to ecological resilience during and after the War.Conclusions The native biota exhibits long-term adaptiveness to marked salinity and temperature fluctuations,alongside a background of invasive species.An evolutionary and recent history of broad environmental tolerances by a large proportion of Black Sea species may enhance their ability to withstand marked environmental changes,including habitat destruction,as during the Kakhovka Dam's breakage and other stressors that continue during the Russia–Ukraine War.The Black Sea community's overall ecological resilience is likely to facilitate persistence and adaptation to the War's effects and the accelerating impacts of climate change,increased global transportation,and invasive species—meriting worldwide conservation agency focus and cooperation.展开更多
Background Accurate measurements of aboveground biomass(AGB)are essential for understanding the planet's carbon balance.The Atlantic Forest of the Serra do Mar in southeastern Brazil contains large areas of well-p...Background Accurate measurements of aboveground biomass(AGB)are essential for understanding the planet's carbon balance.The Atlantic Forest of the Serra do Mar in southeastern Brazil contains large areas of well-preserved remnants,characterized by mountainous terrain with significant orographic contrasts along its elevation gradient.This diverse landscape creates a variety of biophysical factors that strongly influence the spatial distribution of AGB.This study aims to estimate AGB using a hybrid geostatistical methodology,regression kriging simulation(RKS),to analyze AGB spatial distribution at a local scale(84 plots,each 0.01 ha)across a small forest fragment covering the entire tree-covered area(8777 ha).Building on traditional regression kriging method,this study introduces an innovative approach by incorporating Gaussian simulation to interpolate residuals,allowing RKS to account for uncertainties in the estimation process and create new results.This allows us to clearly distinguish exogenous ecological processes from endogenous ones before reaching the model's final estimate.Results Four regression kriging models were created,and the best-performing model used the Enhanced Vegetation Index and direct solar radiation(DSR),achieving an R^(2) of 55%.A Gaussian simulation was performed to interpolate the residuals of this model.The final results indicate that RKS provides accurate AGB estimates(RMSE=1.333 Mg/0.01 ha and R^(2) of 77%).Additionally,the inclusion of DSR as a new predictor variable enhances the precision of AGB estimates.The analysis showed that 63%of the sample pairs exhibited measurable spatial dependence.Conclusions Regression kriging simulation is proposed using Gaussian simulation,altering the classical application of regression kriging.For this,a case study was conducted in the Atlantic Forest of Serra do Mar to estimate the spatial distribution of tree biomass in a forest fragment of this region.We demonstrate that the proposed method better captures the heterogeneity of the region and produces more comprehensive results than regression kriging.Regression kriging simulation estimates tree biomass by considering the actual fluctuations of the spatial distribution of tree biomass in the region,taking into account exogenous and endogenous ecological processes,addressing random noise,and allowing the creation of dynamic maps for use by environmental managers.展开更多
Background Biological invasions pose severe threats to global biodiversity and human well-being.Invading populations often experience negative growth rates during the‘lag phase',leading to Allee effects,a density...Background Biological invasions pose severe threats to global biodiversity and human well-being.Invading populations often experience negative growth rates during the‘lag phase',leading to Allee effects,a density-dependent phenomenon.Allee effects reduce species fitness or plant performance due to low-density populations.The rapid spread and range expansion of an invader,Hyptis suaveolens(L.)Poit.has been reported to have negative impacts on local biodiversity in the invaded regions of the Vindhyan highlands,India.The present study examines the effects of varied population densities of H.suaveolens on its vegetative trait performance,reproductive output,and density-dependent plant population regulations.Understanding the relationship between the population density and trait modulation ability of H.suaveolens at fine and coarse scales could help strategize for management.Methods The study was conducted in invaded habitats of H.suaveolens in the Vindhyan highlands,India.Population density was divided into low-,medium-,and high-density groups.Plant performance was assessed at two scales—fine scale and coarse scale.Plant performance traits,vegetative growth,and reproductive output were estimated as plant traits(Pl Ts)at the fine scale and patch traits(Pa Ts)at the coarse scale.The plasticity response index(PI)was also estimated among three population densities.Results Results showed that Pl Ts-vegetative and reproductive traits,such as plant height,biomass,and number of seeds,were significantly different across densities,with medium-density individuals showing maximum plant height and plant biomass and high-density individuals exhibiting a higher number of seeds per plant.Pa Ts analysis revealed that plant biomass per patch was similar for medium-and high-density populations,whereas the number of seeds per patch was similar in low-and medium-density populations.PI values revealed that Pl Ts showed low,medium,and high plastic responses,while Pa Ts exhibited low and high plastic responses.Conclusions The study concludes that H.suaveolens exhibits density-dependent plant population regulations.As population density increases,low-density populations grow more rapidly,resulting in denser populations.These populations can negatively impact recipient habitats and,if left unchecked,grow into high-density populations with higher seed production.The study suggests that low-density areas should be considered a high priority for developing efficient and cost-effective management strategies.The present study emphasizes the importance of incorporating Allee effects dynamics in invasion studies for predicting high-risk/priority areas for strategizing invasive species management.展开更多
Background Fluvial fish habitat in the Northeastern and Midwestern U.S. is substantially affected by natural landscape factors and anthropogenic stressors, with climate change expected to alter natural influences and ...Background Fluvial fish habitat in the Northeastern and Midwestern U.S. is substantially affected by natural landscape factors and anthropogenic stressors, with climate change expected to alter natural influences and exacerbate stressor effects. To conserve fluvial fish species in the future, it is crucial to understand which fish habitats will be most strongly influenced by changing climate, which species are most sensitive to climate change, and how changes in individual species will affect entire assemblages. To answer these questions, we modeled fluvial fish distributions under projected changes in climate to understand how climate could affect suitability of fish habitat for 55 widely distributed fluvial fishes with differing thermal preferences in the region. Using boosted regression tree models, we predicted distributions of fishes at a stream reach scale using four contemporary climate variables including annual mean air temperature, annual precipitation, and variation in monthly air temperature and precipitation along with seven natural landscape and anthropogenic stressor variables. We then used projected values from eight general circulation models(GCMs) during 2041–2080 to evaluate potential patterns in species richness, turnover, and range shifts under climate change across the study region.Results Most cold-water and cool-water species were projected to lose habitat;however, projected habitat loss also occurred for certain small-bodied warm-water species. The percentage change in species richness of all 55 species across reaches ranged from-40.4 to 33.93%, with regions of major species richness losses occurring across southern portions of the Northeastern coast and southern Midwest regions. Species turnover ranged from 0 to 43.5% with substantial turnover occurring along the Northeastern coast and upper Midwest.Conclusions Temperature and precipitation variation will influence fish species distribution substantially. Our findings provide multiple measures describing patterns of fish community change under climate change to aid management and conservation of stream fishes in the future.展开更多
Background Describing where distribution hotspots and coldspots are located is crucial for any science-based species management and governance.Thus,here we created the world's first Super Species Distribution Mode...Background Describing where distribution hotspots and coldspots are located is crucial for any science-based species management and governance.Thus,here we created the world's first Super Species Distribution Models(SDMs)including all described primate species and the best-available predictor set.These Super SDMs are conducted using an ensemble of modern Machine Learning algorithms,including Maxent,Tree Net,Random Forest,CART,CART Boosting and Bagging,and MARS with the utilization of cloud supercomputers(as an add-on option for more powerful models).For the global cold/hotspot models,we obtained global distribution data from www.GBIF.org(approx.420,000 raw occurrence records)and utilized the world's largest Open Access environmental predictor set of 201 layers.For this analysis,all occurrences have been merged into one multi-species(400+species)pixel-based analysis.Results We present the first quantified pixel-based global primate hotspot prediction for Central and Northern South America,West Africa,East Africa,Southeast Asia,Central Asia,and Southern Africa.The global primate coldspots are Antarctica,the Arctic,most temperate regions,and Oceania past the Wallace line.We additionally described all these modeled hotspots/coldspots and discussed reasons for a quantified understanding of where the world's non-human primates occur(or not).Conclusions This shows us where the focus for most future research and conservation management efforts should be,using state-of-the-art digital data indication tools with reasoning.Those areas should be considered of the highest conservation management priority,ideally following‘no killing zones'and sustainable land stewardship approaches if primates are to have a chance of survival.展开更多
Background The decomposition of organic matter is among the most important ecosystem processes in forest ecosystems,regulating the carbon and nutrient cycle.However,our understanding about how direct(environment and d...Background The decomposition of organic matter is among the most important ecosystem processes in forest ecosystems,regulating the carbon and nutrient cycle.However,our understanding about how direct(environment and decomposer diversity)and indirect effects(environment via decomposer diversity)contribute to deadwood decomposition is limited.We set up a large real-world deadwood experiment in a mixed mountain forest in southeastern Germany considering beech(Fagus sylvatica)and fir(Abies alba)as substrates.We simultaneously tested effects of canopy cover,amount and heterogeneity of surrounding deadwood and a broad set of fungal diversity measures mediated by environment on deadwood density loss after 10 years.Results Deadwood density loss was mainly explained by tree species and canopy cover.Beech showed higher density loss than fir and density loss was larger in open compared to closed canopies.Even though fungal diversity is mediated by environment,the direct effects on density loss were weak and inconsistent across tree species and fungal diversity measures.Conclusions We found weak support for the fungal diversity–ecosystem process relationship for deadwood decomposition.We suggest that deadwood decomposition and the resulting carbon and nutrient cycles in forest ecosystems are primarily regulated by the tree species selected through forest management and canopy disturbances,particularly in the context of climate change.展开更多
Background The global freshwater biodiversity crisis has led to widespread implementation of measures to counteract environmental degradation and biodiversity loss.While these efforts aim to foster recovery,intensifyi...Background The global freshwater biodiversity crisis has led to widespread implementation of measures to counteract environmental degradation and biodiversity loss.While these efforts aim to foster recovery,intensifying stressors continue to drive complex biotic responses,the trajectories and drivers of which are insufficiently understood.This study examines the roles of abiotic stressors,biotic interactions(e.g.,competition),and land use in shaping ecological status changes across Germany,using data from 1599 river sites sampled at least twice between 2004 and 2022.Results Changes in abiotic stressors emerged as the most consistent drivers of ecological status,explaining substantial variation(R^(2)=0.39)and similar slopes for recovery(β=-0.11)and degradation(β=-0.10).Biotic interactions,particularly interspecific competition,also influenced the ecological status(R^(2)=0.11),with stronger positive effects observed during recovery(β=2.99)compared to degradation(β=1.59).Land use effects varied by context:Streams in catchments with higher cropland or urban areas showed greater likelihood of recovery,whereas streams in forested catchments were more prone to degradation.These results highlight the interplay of abiotic and biotic factors in driving ecological processes of recovery and degradation.Conclusion These findings emphasize the critical role of improving water quality for enhancing biodiversity and ecological status in rivers,while also demonstrating the importance of biotic interactions and land use context in driving recovery dynamics.Integrating these insights into management and restoration efforts can enhance freshwater ecosystem resilience in the face of escalating environmental pressures.展开更多
Background Identifying the processes that govern community assembly along elevational gradients has been a central theme in ecology,especially in montane ecosystems where abundant species and strong turnover are prese...Background Identifying the processes that govern community assembly along elevational gradients has been a central theme in ecology,especially in montane ecosystems where abundant species and strong turnover are present.However,our understanding of how the relative importance of deterministic and stochastic processes varies along elevational gradients remains limited.Here,we compiled a rigorously curated dataset of elevational distributions of 734 breeding bird species across the Hengduan Mountains in China to assess the dominant underlying mechanisms of bird community assembly at both intra-community and inter-community scales across four elevation zones:low,middle,subalpine,and alpine.Results At the intra-community scale,homogeneous dispersal played a pivotal role in driving community assembly of breeding birds across the Hengduan Mountains.Deterministic processes became more influential with increasing elevation,whereas stochastic processes prevailed in low,middle,and subalpine zones.At inter-community scale,assemblages from different elevation zones were more differentiated by dispersal limitation.Non-Passeriformes experienced more obvious influence of homogeneous dispersal but were less subject to dispersal limitation compared to Passeriformes.Conclusions Our findings highlight the role of stochastic processes in shaping biotic communities in montane ecosystems,but this effect is scale-dependent.The transition from stochastic to deterministic processes along elevational gradients suggests that environmental factors become more influential at higher elevations.Species dispersal ability may affect the relative importance of these two processes shaping community assembly.展开更多
Background Increasing atmospheric nitrogen(N)deposition is a major threat to plant diversity globally.Recent observations show that the reduced-to-oxidized(NH_(x)/NO_(y))ratio of N deposition has been changing spatial...Background Increasing atmospheric nitrogen(N)deposition is a major threat to plant diversity globally.Recent observations show that the reduced-to-oxidized(NH_(x)/NO_(y))ratio of N deposition has been changing spatially and temporally.How and to what extent different N forms(i.e.,NH_(x)and NO_(y))influence grassland plant species loss are still unclear.Methods We employed a field manipulative experiment by using three N forms[i.e.,Ca(NO_(3))_(2),NH_(4)NO_(3),and(NH_(4))_(2)SO_(4)]with six N addition levels(0,4,8,16,24,32 g N m^(-2)year^(-1))in a temperate grassland and conducted a greenhouse experiment culturing four plant species corresponding different plant functional groups under Ca(NO_(3))_(2)or(NH_(4))_(2)SO_(4)addition.Results Results from our field experiment showed that the plant species loss rate was greater under NH_(4)^(+)-N than NO_(3)^(-)-N enrichment.Plant species loss was driven by light asymmetry under NO_(3)^(-)-N enrichment,while it was co-driven by light asymmetry and soil acidification under NH_(4)NO_(3)enrichment.Under NH_(4)^(+)-N enrichment,light asymmetry,pH decrease,NH_(4)^(+) toxicity,and metal toxicity jointly affected species loss.The greenhouse experiment provided direct evidence that legumes and forbs are more physiologically susceptible to NH_(4)^(+)-induced toxicity than grasses.Conclusions Our results emphasize that N forms play a vital role in affecting grassland plant diversity.This suggests that regions with higher NH_(x) enrichment may experience more severe plant diversity losses as N deposition continues to increase.Therefore,appropriate measures should be adopted to mitigate species losses.展开更多
Background Tick borne diseases are re-emerging around the world,including India.Information about the occurrence of the tick vectors in different geographical locations is essential for controlling the diseases.Tick s...Background Tick borne diseases are re-emerging around the world,including India.Information about the occurrence of the tick vectors in different geographical locations is essential for controlling the diseases.Tick surveys have not been conducted in many parts of India and information on the current prevalence of tick vectors is not available in all states of India.Many studies have been carried out utilizing modelling methods to predict the distribution of tick species in other countries.The MaxEnt model is widely used for predicting tick species distribution using bioclimatic variables.Lyme disease vectors such as Ixodes sp.,Amblyomma sp.,and Dermacentor sp.are the most commonly predicted tick species.However,very few studies have been carried out to predict the distribution of tick species in India.Haemaphysalis spinigera,the primary Kyasanur Forest Disease vector,was predicted along the Western Ghats using the MaxEnt model.Rhipicephalus(Boophilus)microplus was predicted across India using the generalized linear model(GLM).Identifying the tick vectors in transmitting the infection through conventional survey and identification methods is cumbersome due to the less number of experienced persons available.Prediction of tick vectors of public health concern,including other tick species in different geographical regions of Tamil Nadu,India,is essential for the prevention and control of tick-borne disease in humans and domestic animals.The present study adopts the package‘SSDM’(stacked species distribution models)with R software containing ensemble species distribution models to predict the distribution of tick species using different available environmental and climatic data.Results The categorical variables such as land use and land cover(LULC),soil type,elevation,Bio1,Bio10,Bio15,Bio19 and Bio8 contributed more to modelling the distribution of tick species.MaxEnt,GLM,GBM and GAM are suitable models for predicting the tick species distribution in the present study.Among these models,MaxEnt is the most suitable model for predicting tick species distribution in Tamil Nadu,India.Conclusions Our results suggest that MaxEnt is a suitable model for predicting the distribution of tick species.Both environmental factors such as LULC,elevation and soil type and bioclimatic factors such as temperature and precipitation contribute significantly to predicting tick species distribution in domestic animals in Tamil Nadu.The SSDM package is very useful and user-friendly graphical user interface for modelling the distribution of tick species.However,the package can be further improved by using higher resolution raster variables in larger areas,which is not currently supported.The predicted elevation range of Ha.spinigera distribution could not be provided due to software limitations.展开更多
Background The impact of vessel-induced waves on macrophyte communities in lakes remains controversial,due to a lack of comprehensive assessments which also consider mechanistic effects on ecological processes during ...Background The impact of vessel-induced waves on macrophyte communities in lakes remains controversial,due to a lack of comprehensive assessments which also consider mechanistic effects on ecological processes during early life stages.This study investigates both the direct and indirect effects of such waves on the early life stages of macrophytes in a case study of Lake W?rthersee,Austria.The study focuses on Characeae species and Najas intermedia which have both experienced significant declines in Lake W?rthersee.Results The linear wave theory was applied to model typical small vessel-induced waves,characterized by wave heights of 0.05–0.30 m and periods of 1 and 3 s.Relevant characteristics for testing remobilization of oospores and seeds like geometric dimensions and density were experimentally determined by field data.Sediment samples from ten locations across six beach sites at depths ranging from 0.8 to 2.2 m were collected and analyzed for oospore presence and sediment texture.Results indicate that maximum wave scenarios can affect oospores and seeds directly by motion activation at water depths down to 3.75 m.Moderate wave scenarios,which are assumed to occur more frequently,can mobilize those particles between 0.75 and 2.25 m water depth.This corresponds to our field data,where 95%of oospores were found in samples from water depths≥2 m.The mobilization disrupts germination processes and impedes the recovery of macrophyte populations.Additionally,in the study lake and other fine-sediment dominated lakes,a significant fraction of sediments can be initiated to motion by small vessel-induced waves,which may indirectly affect germination by altering habitat conditions like turbidity and nutrients.However,grain size distribution showed minimal variation with depth at the same sampling sites,indicating limited sediment redistribution at the selected sampling sites by small vessel-induced waves.No significant correlation was found between oospore abundance and sediment grain size.Conclusions These findings suggest that the impacts of increased traffic of small vessels in lakes may be a key factor contributing to the decline of macrophyte species in shallow waters by motion triggering of oospores and seeds,with broader implications for the recreational management.展开更多
Nutrient concentrations in foliage are often used to infer whether growth of a species at a particular site is likely limited by low supply of soil nutrients.Sometimes ratios of nutrient elements(stoichiometry)are tho...Nutrient concentrations in foliage are often used to infer whether growth of a species at a particular site is likely limited by low supply of soil nutrients.Sometimes ratios of nutrient elements(stoichiometry)are thought to be useful,as if a higher supply of one element might somehow physiologically alleviate,or interfere with,a low supply of another.The growth of most forests is indeed commonly limited by low supplies of nutrients in soils,but foliar chemistry has proven unable to discern nutrient limitations.We illustrate this conclusion using two large,regional experiments with Eucalyptus in Brazil and loblolly pine(Pinus taeda L.)in the southeastern USA.In both cases,most sites showed profitable increases in growth after fertilization,and nutrient concentrations in foliage differed substantially across sites.However,foliar nutrient concentrations(and stoichiometric ratios)did not provide useful information about forest growth responses.We urge authors,reviewers,and editors not to expect foliar chemistry to be a useful tool for diagnosing nutrient limitations in forests,unless strong,local evidence demonstrates a reliable association.展开更多
Background Biochar is widely recognized for its capacity to capture and store carbon in soil attributed to its stable structure. However, in most field studies examining the effects of biochar application on soil resp...Background Biochar is widely recognized for its capacity to capture and store carbon in soil attributed to its stable structure. However, in most field studies examining the effects of biochar application on soil respiration, the impact of rainfall events on the experimental outcomes has not been taken into account. To address the existing gap in this research field, we conducted a one-year study on soil respiration in an urban camphor forest and collected the data of soil respiration, soil temperature, soil moisture, and the rainfall events closest to the soil respiration monitoring time. We specifically examined how different stages of rainfall events influenced soil respiration in relation to biochar application.Results This study found that the annual average soil respiration rate increased with the doses of biochar application, and the soil respiration rate under the biochar application at the dose of 45 t/ha showed a significant rise. The stages of rainfall events, rainfall amount, and the interaction effect of the two, and biochar doses significantly affected soil respiration. The parameters in the regression model for soil respiration, soil temperature and moisture varied with the different stages of rainfall events and the doses of biochar application. The biochar application eliminated the significant effect of soil moisture on soil respiration during one day after rainfall events. The significant correlation between soil moisture and the temperature sensitivity of soil respiration(Q10) was eliminated by biochar application, both during one day after rainfall events and more than eight days after rainfall events.Conclusions Our findings indicated that the rice straw biochar application has a short-term positive effect on soil respiration in urban camphor forests. The rainfall events affect the field soil respiration monitored in the biochar applications, possibly by affecting the soil respiration response to soil temperature and moisture under different doses of biochar application. The impact of rainfall events on soil respiration in biochar application experiments should be considered in future forest monitoring management and practice.展开更多
Background The increasing demand for large-scale hydroelectric dam development in tropical developing countries has led to significant land-use changes that impact biodiversity,particularly in megadiverse countries,su...Background The increasing demand for large-scale hydroelectric dam development in tropical developing countries has led to significant land-use changes that impact biodiversity,particularly in megadiverse countries,such as Malaysia.Although many recent infrastructure projects incorporate sustainable concepts for wildlife monitoring and management,studies on the impacts of habitat fragmentation on ground-dwelling birds during the development phase remain scarce.This study aimed to assess the response of forest bird communities,particularly the ground-dwelling birds,across different phases of hydroelectric dam development using infrared camera traps.We collected data from 14 sampling sites in Nenggiri hydroelectric dam catchment area for 25 months across three developmental phases:pre-logging,logging,and construction.Results We recorded 1045 occurrences of 33 bird species,including the critically endangered Malayan Crestless Fireback Lophura erythrophthalma and the endangered Malayan Peacock-Pheasant Polyplectron malacense.There were significant changes between phases,with a notable decrease in the number of pheasants detected,such as the Great Argus Argusianus argus and Malayan Crested Fireback Lophura rufa,especially during the construction phase.Indicator species analysis(Ind Val)identified seven species showing strong associations(p<0.05)with specific development phases,including the Barred Cuckoo-Dove Macropygia unchall and Great Argus for the pre-logging phase.Conclusion These results highlight the vulnerability of ground-dwelling birds,particularly pheasants,to habitat disturbances from large-scale development activities.We propose incorporating camera trap assessments into major infrastructure projects to identify key locations of conservation-priority bird species,and to inform targeted rescue or translocation efforts,particularly during high-impact phases such as habitat clearance and dam impoundment.展开更多
Background The changing hydrological conditions in wetland ecosystems are often accompanied by salt fluctuations.However,how fluctuating salt conditions affect growth and interspecific competition of dominant plants i...Background The changing hydrological conditions in wetland ecosystems are often accompanied by salt fluctuations.However,how fluctuating salt conditions affect growth and interspecific competition of dominant plants in wetlands remains unclear.This study aims to investigate the response of growth and competitive ability of a dominant species in inland salt marshes,Bolboschoenus planiculmis,under different salt conditions and test if B.planiculmis is more adapted to the fluctuating salt environments.Methods We quantified the growth indices and competitive response of B.planiculmis and two other dominant species Phragmites australis and Suaeda salsa under five salt treatments(control,constant Na Cl,constant mixed salt,pulsed increase of mixed salt,and fixed increase of mixed salt)and two competition treatments(no competition and interspecific competition)in a greenhouse experiment.Results We found that the total biomass of B.planiculmis was significantly higher under the mixed salt treatments compared to the Na Cl treatment,and was more advantageous than S.salsa in the mixed salt treatments when competing with it.Fluctuating mixed salt treatments significantly increased the total biomass of B.planiculmis more than the constant mixed salt treatment.Particularly,B.planiculmis benefited more than P.australis or S.salsa in competition.Moreover,the competitive response of B.planiculmis was stronger than the other two species in the fluctuating mixed salt treatments,although the biomass of B.planiculmis was lower than the other two species.Conclusion Our results demonstrated that fluctuating salt conditions prioritized interspecific competition of B.planiculmis.We support the competition-to-stress hypothesis that the competition ability rather than salt stress tolerance was the main determinant of species survival in fluctuating salt with a less stressful survival condition.Our study provides important information in understanding community composition changes and restoration of degraded salt marshes.展开更多
Background Soil respiration(Rs)is critical for maintaining the terrestrial carbon(C)cycling,and considerable research has focused on its response to climate warming.However,our knowledge of the mechanistic basis of th...Background Soil respiration(Rs)is critical for maintaining the terrestrial carbon(C)cycling,and considerable research has focused on its response to climate warming.However,our knowledge of the mechanistic basis of the plant functional composition on Rs is limited.We conducted a 2-year field warming experiment to explore Rs responses to different warming levels across three types of alpine grasslands:alpine steppe(AS)dominated by grasses,alpine meadow(AM)and alpine swamp meadow(ASM),both of the latter two dominated by sedges.Results Our findings revealed contrasting effects of warming on Rs across three alpine grassland types:minimal change in the AS,a significant 24%increase in the AM,and a 20%decrease in the ASM.Dominant plant functional groups in each grassland type play an important role in regulating the response of Rs to warming.Moreover,we found a negative correlation between plant height and Rs in the grass-dominated AS and sedge-dominated AM.However,there was no correlation between plant height and Rs in ASM.Furthermore,Rs was regulated by both soil moisture and soil temperature,while in ASM it was constrained by soil moisture levels.Conclusions Our results underscore the importance of incorporating plant functional composition mechanisms when assessing ecosystem C balance under climate warming.Future studies should consider the ecosystem-specific characteristics when investigating the connections between plant community structure,traits,and ecosystem function.展开更多
基金funded by the National Natural Science Foundation of China (Nos. 42361144882 to T.L., and 42471322 to Y.H.)
文摘Background Ecosystem services(ESs)are fundamental to ensuring human well-being and sustainable development.However,the complex nonlinear relationships between ESs and social systems are still not fully recognized at present.Here,we used a comprehensive indicator framework,a coupling coordination degree(CCD)model,and a GeoDetector model to measure the CCD and development level of ESs and social systems in Sanmenxia City,Henan Province,China from 2000 to 2020,analyze the spatial patterns and temporal variations of their development,and quantify the influence of 15 factors on the spatial heterogeneity of their CCD.Results We observed that the increase of social system development level in Sanmenxia City was higher than that of ESs'provisioning capacity.From 2000 to 2020,the ecosystem service index value of Sanmenxia City increased by about 25%,while the level of social system development increased by 118.9%.The coordination between ESs and social systems improved by 25%,indicating that their relationships were shifting from trade-offs to synergies.Lushi County(one of the six administrative regions of Sanmenxia City)had the highest level of CCD,but the overall coordination remained relatively weak in Sanmenxia City,and none of the six administrative regions achieved a high level of coordination.CCD was influenced by multiple interacting factors,with topography and land use patterns being the primary drivers.Conclusions Optimizing the spatial layout of ecological space,agricultural space,and urban space based on natural geographic patterns can be an effective way to improve CCD.Accordingly,we identified the impacts of potential barriers on sustainable development and provided multiple possible effective actions.Our findings deepen the knowledge and understanding of the“human-nature relationships”,which are of great significance in promoting the synergistic development of social and ecological systems.
基金financially supported by grants from the National Natural Science Foundation of China (41930643 and 42273084)Natural Science Foundation of Henan Province (242300421039)Science and Technology Development Plan Project of Henan Province (242102110186)
文摘Background The temperate grasslands are facing numerous pressures from global change.Despite their essential ecological and economic role,how their microbial communities react to multiple varying factors remain obscure.In this study,we simulated three global change drivers,i.e.,nitrogen deposition(ambient N vs.elevated N,a N vs.e N),precipitation increase(ambient precipitation vs.elevated precipitation,a P vs.e P),and mowing,represented experimentally by clipping(unclipped vs.clipped,u C vs.CL),together in all possible combinations in a temperate semi-arid grassland ecosystem.Results Nitrogen addition had negative effects on the richness of bacterial and fungal communties,significantly changed their structures(P<0.05)and increased their dissimilarities(P<0.05),while water addition had positive effects on fungal and protist communities and significantly stimulated theα-diversity of protist communities under N addition without clipping,which was in contrast to the effect in clipped plots.Clipping had a marginal effect on fungal communities and significantly affected protist communities(P<0.05).A notable interactive effect of N and precipitation on the structure of bacterial communities and a significant interactive effect of clipping and precipitation on protists were found.Combination effects of N with precipitation or clipping on module aggregation of metanetworks were also observed between u C and CL,as well as a P and e P meta-networks.Bacterial,fungal,and protist communities varied in their assembly mechanisms,and their assembly processes differed in response to the three global change factors.Conclusions Overall,N,water addition,and clipping individually and/or interactively,in distinct degrees,altered soil microbial interaction,community structure,and the potential function in a semi-arid steppe.These findings enhance our understanding of soil microbial community assembly and provide a scientific basis for managing temperate grasslands,particularly in the context of global change's impact on ecosystem function and stability.
基金supported by the National Key Research and Development Program of China(2024YFD150140302)the Natural Science Foundation of China(Nos.32271843,41888101 and 41871027)the project of forestry science and technology innovation platform(No.LLC20245)
文摘Background The forest floor humus layer is an important carbon pool and serves as a key interface that influences forest soil carbon and nutrient cycling,especially in temperate and boreal forests.Over the past decades,China has implemented numerous forestry ecological programs,leading to an increasing quantity of forest floor litter and the formation of humus layers,which has altered the interface between aboveground litter and surface soil.Our previous study revealed that these alterations affect the litter decomposition rate;however,it is still unclear how the litter decomposition process changes,how nutrients are released or imported and the extent to which these changes depend on the humus layer.Results In this study,we used a 535-day in situ litterbag experiment to monitor the litter decomposition process and nutrient variations under forest floor humus layer removal in a Pinus sylvestris var.mongolica plantation in Northeast China.The results revealed that the litter decomposed quickly when a forest floor humus layer was present,with the decomposition rate constant(k value)increasing from 0.122 to 0.328.Accordingly,during decomposition,the litter C,N and P concentrations increased,whereas their contents varied only slightly(with the exception of the litter P content,which decreased significantly)compared with those in the treatment where the humus layer was removed.However,both the litter C and N contents decreased,whereas the litter P content increased significantly compared with the initial litter content.Moreover,the litter C:N,C:P and N:P ratios decreased significantly during decomposition.In addition,the microbial community diversity of the litter showed no significant change,whereas the relative abundances of several major fungal and bacterial taxa at the phylum and genus levels varied significantly.Furthermore,redundancy analysis revealed effective relationships among the k values,chemical traits and microbial communities,and the least squares method suggested that the C,P and C:P ratios of the litter were significantly correlated with the litter decomposition rate.Conclusions These results enhance our understanding of the role of the humus layer in forest soil-plant carbon and nutrient cycling and should be considered in carbon cycle models in the future.
文摘Background The mangrove ecosystem has the highest carbon sink potential which significantly contributes to bringing carbon neutrality.Understanding the carbon stock dynamics along the age of forest stands in the mangrove forest ecosystem is of significance for managing the forests and their carbon accumulation.This study aimed to estimate the forest structural attributes,biomass and total ecosystem carbon stock(TECS)of old natural(age>50 years)and young planted(age~20 years)mangrove forest stands at Bichitrapur Mangrove Reserve Forest in eastern coast of India.We also attempted to understand the interrelationship of structural attributes,biomass and soil properties in the mangrove forests.To achieve the results,twenty random plots were established(size:20 m×25 m)and suitable allometric equations along with species-specific wood density values were used to estimate the biomass and carbon stock.Results Altogether,29 plant species(18 exclusive and 11 associate species)were recorded.The mean total biomass(±SE)and soil organic carbon(at 30 cm depth)were 165.31±20.89 t ha^(-1)and 40.20±1.24 t C ha^(-1)for young stands,and 586.12±56.74 t ha^(-1)and 49.68±2.39 t C ha^(-1)for old stands,respectively.Among mangrove species,Avicennia marina contributed the highest vegetation biomass in both forest stands(59.72 t ha^(-1)and 262.28 t ha^(-1)in young and old stands,respectively),followed by Avicennia officinalis(35.05 t ha^(-1))and Sonneratia apetala(26.09 t ha^(-1))in young stand and Avicennia alba(169.28 t ha^(-1))and Avicennia officinalis(115.58 t ha^(-1))in old stand.The mean TECS was 235.62±27.34 t C ha^(-1).The contribution of vegetation and soil to TECS was 63%and 37%in the young stand,whereas in the old stand it was 83%and 17%,respectively.The correlation analyses revealed that mean stand height(r=0.87),basal area(r=0.99),soil nitrogen(r=0.76),potassium(r=0.78),and carbon(r=0.80)were significantly positively correlated with total biomass at p<0.01.Conclusions Our results demonstrate that old mangrove forest stands store substantially high carbon stock than young planted forest stands,implying the role of forest age in determining the carbon storage potential of mangrove ecosystems.
文摘Background The effects of war on biodiversity,habitats,ecosystem services,and water,seafood,and fishing resources are complex and long-lasting,yet their ongoing environmental analyses are limited.The Russia–Ukraine War(2022–present)comprises a unique ecological situation to examine biodiversity effects on the distinctive cold-temperate northern Black Sea ecosystem,which has an intriguing biogeographic history and high endemism resulting from geographic isolation and differentiation.Results We summarize negative and positive effects from the War on the aquatic(marine,estuarine,and freshwater)biota and their habitats,focusing on investigations by the Institute of Marine Biology,National Academy of Sciences of Ukraine.Negative effects include toxins and habitat damage from oil spills,shelling,mining,explosions,flooding,and fires;along with disregard of Protected Areas.Positive effects are reduced anthropogenic loads from less shipping,fishing,trawling,recreation,hydraulic engineering,construction,and tourism.The Kakhovka Dam's destruction on June 6,2023 was the greatest ecological catastrophe to date,causing extensive downstream flooding with freshwaters and pollutants that destroyed many populations and habitats.We discern that many effects have been temporary,with habitats and species replenishing,and some reverting to their historical biota characteristic of lower salinity regimes.However,significant habitat destruction,disturbances,and pollutant damages remain.Since many of the native species evolved in conditions favoring broad salinity,temperature,and oxygen tolerances,the northern Black Sea ecosystem appears pre-adapted for ecological recovery and persistence,which may equate to ecological resilience during and after the War.Conclusions The native biota exhibits long-term adaptiveness to marked salinity and temperature fluctuations,alongside a background of invasive species.An evolutionary and recent history of broad environmental tolerances by a large proportion of Black Sea species may enhance their ability to withstand marked environmental changes,including habitat destruction,as during the Kakhovka Dam's breakage and other stressors that continue during the Russia–Ukraine War.The Black Sea community's overall ecological resilience is likely to facilitate persistence and adaptation to the War's effects and the accelerating impacts of climate change,increased global transportation,and invasive species—meriting worldwide conservation agency focus and cooperation.
文摘Background Accurate measurements of aboveground biomass(AGB)are essential for understanding the planet's carbon balance.The Atlantic Forest of the Serra do Mar in southeastern Brazil contains large areas of well-preserved remnants,characterized by mountainous terrain with significant orographic contrasts along its elevation gradient.This diverse landscape creates a variety of biophysical factors that strongly influence the spatial distribution of AGB.This study aims to estimate AGB using a hybrid geostatistical methodology,regression kriging simulation(RKS),to analyze AGB spatial distribution at a local scale(84 plots,each 0.01 ha)across a small forest fragment covering the entire tree-covered area(8777 ha).Building on traditional regression kriging method,this study introduces an innovative approach by incorporating Gaussian simulation to interpolate residuals,allowing RKS to account for uncertainties in the estimation process and create new results.This allows us to clearly distinguish exogenous ecological processes from endogenous ones before reaching the model's final estimate.Results Four regression kriging models were created,and the best-performing model used the Enhanced Vegetation Index and direct solar radiation(DSR),achieving an R^(2) of 55%.A Gaussian simulation was performed to interpolate the residuals of this model.The final results indicate that RKS provides accurate AGB estimates(RMSE=1.333 Mg/0.01 ha and R^(2) of 77%).Additionally,the inclusion of DSR as a new predictor variable enhances the precision of AGB estimates.The analysis showed that 63%of the sample pairs exhibited measurable spatial dependence.Conclusions Regression kriging simulation is proposed using Gaussian simulation,altering the classical application of regression kriging.For this,a case study was conducted in the Atlantic Forest of Serra do Mar to estimate the spatial distribution of tree biomass in a forest fragment of this region.We demonstrate that the proposed method better captures the heterogeneity of the region and produces more comprehensive results than regression kriging.Regression kriging simulation estimates tree biomass by considering the actual fluctuations of the spatial distribution of tree biomass in the region,taking into account exogenous and endogenous ecological processes,addressing random noise,and allowing the creation of dynamic maps for use by environmental managers.
基金the Institution of Eminence(IOE),University of Delhithe Science and Engineering Research Board,Department of Science and Technology,India
文摘Background Biological invasions pose severe threats to global biodiversity and human well-being.Invading populations often experience negative growth rates during the‘lag phase',leading to Allee effects,a density-dependent phenomenon.Allee effects reduce species fitness or plant performance due to low-density populations.The rapid spread and range expansion of an invader,Hyptis suaveolens(L.)Poit.has been reported to have negative impacts on local biodiversity in the invaded regions of the Vindhyan highlands,India.The present study examines the effects of varied population densities of H.suaveolens on its vegetative trait performance,reproductive output,and density-dependent plant population regulations.Understanding the relationship between the population density and trait modulation ability of H.suaveolens at fine and coarse scales could help strategize for management.Methods The study was conducted in invaded habitats of H.suaveolens in the Vindhyan highlands,India.Population density was divided into low-,medium-,and high-density groups.Plant performance was assessed at two scales—fine scale and coarse scale.Plant performance traits,vegetative growth,and reproductive output were estimated as plant traits(Pl Ts)at the fine scale and patch traits(Pa Ts)at the coarse scale.The plasticity response index(PI)was also estimated among three population densities.Results Results showed that Pl Ts-vegetative and reproductive traits,such as plant height,biomass,and number of seeds,were significantly different across densities,with medium-density individuals showing maximum plant height and plant biomass and high-density individuals exhibiting a higher number of seeds per plant.Pa Ts analysis revealed that plant biomass per patch was similar for medium-and high-density populations,whereas the number of seeds per patch was similar in low-and medium-density populations.PI values revealed that Pl Ts showed low,medium,and high plastic responses,while Pa Ts exhibited low and high plastic responses.Conclusions The study concludes that H.suaveolens exhibits density-dependent plant population regulations.As population density increases,low-density populations grow more rapidly,resulting in denser populations.These populations can negatively impact recipient habitats and,if left unchecked,grow into high-density populations with higher seed production.The study suggests that low-density areas should be considered a high priority for developing efficient and cost-effective management strategies.The present study emphasizes the importance of incorporating Allee effects dynamics in invasion studies for predicting high-risk/priority areas for strategizing invasive species management.
基金funded by the United States Geological Survey Aquatic GAP Project
文摘Background Fluvial fish habitat in the Northeastern and Midwestern U.S. is substantially affected by natural landscape factors and anthropogenic stressors, with climate change expected to alter natural influences and exacerbate stressor effects. To conserve fluvial fish species in the future, it is crucial to understand which fish habitats will be most strongly influenced by changing climate, which species are most sensitive to climate change, and how changes in individual species will affect entire assemblages. To answer these questions, we modeled fluvial fish distributions under projected changes in climate to understand how climate could affect suitability of fish habitat for 55 widely distributed fluvial fishes with differing thermal preferences in the region. Using boosted regression tree models, we predicted distributions of fishes at a stream reach scale using four contemporary climate variables including annual mean air temperature, annual precipitation, and variation in monthly air temperature and precipitation along with seven natural landscape and anthropogenic stressor variables. We then used projected values from eight general circulation models(GCMs) during 2041–2080 to evaluate potential patterns in species richness, turnover, and range shifts under climate change across the study region.Results Most cold-water and cool-water species were projected to lose habitat;however, projected habitat loss also occurred for certain small-bodied warm-water species. The percentage change in species richness of all 55 species across reaches ranged from-40.4 to 33.93%, with regions of major species richness losses occurring across southern portions of the Northeastern coast and southern Midwest regions. Species turnover ranged from 0 to 43.5% with substantial turnover occurring along the Northeastern coast and upper Midwest.Conclusions Temperature and precipitation variation will influence fish species distribution substantially. Our findings provide multiple measures describing patterns of fish community change under climate change to aid management and conservation of stream fishes in the future.
文摘Background Describing where distribution hotspots and coldspots are located is crucial for any science-based species management and governance.Thus,here we created the world's first Super Species Distribution Models(SDMs)including all described primate species and the best-available predictor set.These Super SDMs are conducted using an ensemble of modern Machine Learning algorithms,including Maxent,Tree Net,Random Forest,CART,CART Boosting and Bagging,and MARS with the utilization of cloud supercomputers(as an add-on option for more powerful models).For the global cold/hotspot models,we obtained global distribution data from www.GBIF.org(approx.420,000 raw occurrence records)and utilized the world's largest Open Access environmental predictor set of 201 layers.For this analysis,all occurrences have been merged into one multi-species(400+species)pixel-based analysis.Results We present the first quantified pixel-based global primate hotspot prediction for Central and Northern South America,West Africa,East Africa,Southeast Asia,Central Asia,and Southern Africa.The global primate coldspots are Antarctica,the Arctic,most temperate regions,and Oceania past the Wallace line.We additionally described all these modeled hotspots/coldspots and discussed reasons for a quantified understanding of where the world's non-human primates occur(or not).Conclusions This shows us where the focus for most future research and conservation management efforts should be,using state-of-the-art digital data indication tools with reasoning.Those areas should be considered of the highest conservation management priority,ideally following‘no killing zones'and sustainable land stewardship approaches if primates are to have a chance of survival.
基金funded by the German Research Foundation(Project number:BA 5127/3-1)supported by the Czech Science Foundation(21-09334J)supported by the Ministry of Education,Youth and Sports of the Czech Republic(CZ.02.01.01/00/22_008/0004597)
文摘Background The decomposition of organic matter is among the most important ecosystem processes in forest ecosystems,regulating the carbon and nutrient cycle.However,our understanding about how direct(environment and decomposer diversity)and indirect effects(environment via decomposer diversity)contribute to deadwood decomposition is limited.We set up a large real-world deadwood experiment in a mixed mountain forest in southeastern Germany considering beech(Fagus sylvatica)and fir(Abies alba)as substrates.We simultaneously tested effects of canopy cover,amount and heterogeneity of surrounding deadwood and a broad set of fungal diversity measures mediated by environment on deadwood density loss after 10 years.Results Deadwood density loss was mainly explained by tree species and canopy cover.Beech showed higher density loss than fir and density loss was larger in open compared to closed canopies.Even though fungal diversity is mediated by environment,the direct effects on density loss were weak and inconsistent across tree species and fungal diversity measures.Conclusions We found weak support for the fungal diversity–ecosystem process relationship for deadwood decomposition.We suggest that deadwood decomposition and the resulting carbon and nutrient cycles in forest ecosystems are primarily regulated by the tree species selected through forest management and canopy disturbances,particularly in the context of climate change.
基金funded by the Deutsche Forschungsgemeinschaft(DFG,German Research FoundationCRC 1439/1,project number:426547801)
文摘Background The global freshwater biodiversity crisis has led to widespread implementation of measures to counteract environmental degradation and biodiversity loss.While these efforts aim to foster recovery,intensifying stressors continue to drive complex biotic responses,the trajectories and drivers of which are insufficiently understood.This study examines the roles of abiotic stressors,biotic interactions(e.g.,competition),and land use in shaping ecological status changes across Germany,using data from 1599 river sites sampled at least twice between 2004 and 2022.Results Changes in abiotic stressors emerged as the most consistent drivers of ecological status,explaining substantial variation(R^(2)=0.39)and similar slopes for recovery(β=-0.11)and degradation(β=-0.10).Biotic interactions,particularly interspecific competition,also influenced the ecological status(R^(2)=0.11),with stronger positive effects observed during recovery(β=2.99)compared to degradation(β=1.59).Land use effects varied by context:Streams in catchments with higher cropland or urban areas showed greater likelihood of recovery,whereas streams in forested catchments were more prone to degradation.These results highlight the interplay of abiotic and biotic factors in driving ecological processes of recovery and degradation.Conclusion These findings emphasize the critical role of improving water quality for enhancing biodiversity and ecological status in rivers,while also demonstrating the importance of biotic interactions and land use context in driving recovery dynamics.Integrating these insights into management and restoration efforts can enhance freshwater ecosystem resilience in the face of escalating environmental pressures.
基金supported by the National Natural Science Foundation of China(32130013)the National Key Research and Development Program of China(2022YFC2601601)+2 种基金the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK05010112,2019QZKK0304-02)Dynamic Monitoring of Distribution,Quantity and Activity of Typical Large and Medium-sized Mammals in the Yarlung Tsangpo River Basin(54000022T000000071200)the Institute of Zoology,Chinese Academy of Sciences(2023IOZ0104)
文摘Background Identifying the processes that govern community assembly along elevational gradients has been a central theme in ecology,especially in montane ecosystems where abundant species and strong turnover are present.However,our understanding of how the relative importance of deterministic and stochastic processes varies along elevational gradients remains limited.Here,we compiled a rigorously curated dataset of elevational distributions of 734 breeding bird species across the Hengduan Mountains in China to assess the dominant underlying mechanisms of bird community assembly at both intra-community and inter-community scales across four elevation zones:low,middle,subalpine,and alpine.Results At the intra-community scale,homogeneous dispersal played a pivotal role in driving community assembly of breeding birds across the Hengduan Mountains.Deterministic processes became more influential with increasing elevation,whereas stochastic processes prevailed in low,middle,and subalpine zones.At inter-community scale,assemblages from different elevation zones were more differentiated by dispersal limitation.Non-Passeriformes experienced more obvious influence of homogeneous dispersal but were less subject to dispersal limitation compared to Passeriformes.Conclusions Our findings highlight the role of stochastic processes in shaping biotic communities in montane ecosystems,but this effect is scale-dependent.The transition from stochastic to deterministic processes along elevational gradients suggests that environmental factors become more influential at higher elevations.Species dispersal ability may affect the relative importance of these two processes shaping community assembly.
基金financially supported by the National Natural Science Foundation of China(42203077,32192462)the Chinese Universities Scientific Fund(2020RC009)the 2115 Talent Development Program of China Agricultural University(1201-00109017)
文摘Background Increasing atmospheric nitrogen(N)deposition is a major threat to plant diversity globally.Recent observations show that the reduced-to-oxidized(NH_(x)/NO_(y))ratio of N deposition has been changing spatially and temporally.How and to what extent different N forms(i.e.,NH_(x)and NO_(y))influence grassland plant species loss are still unclear.Methods We employed a field manipulative experiment by using three N forms[i.e.,Ca(NO_(3))_(2),NH_(4)NO_(3),and(NH_(4))_(2)SO_(4)]with six N addition levels(0,4,8,16,24,32 g N m^(-2)year^(-1))in a temperate grassland and conducted a greenhouse experiment culturing four plant species corresponding different plant functional groups under Ca(NO_(3))_(2)or(NH_(4))_(2)SO_(4)addition.Results Results from our field experiment showed that the plant species loss rate was greater under NH_(4)^(+)-N than NO_(3)^(-)-N enrichment.Plant species loss was driven by light asymmetry under NO_(3)^(-)-N enrichment,while it was co-driven by light asymmetry and soil acidification under NH_(4)NO_(3)enrichment.Under NH_(4)^(+)-N enrichment,light asymmetry,pH decrease,NH_(4)^(+) toxicity,and metal toxicity jointly affected species loss.The greenhouse experiment provided direct evidence that legumes and forbs are more physiologically susceptible to NH_(4)^(+)-induced toxicity than grasses.Conclusions Our results emphasize that N forms play a vital role in affecting grassland plant diversity.This suggests that regions with higher NH_(x) enrichment may experience more severe plant diversity losses as N deposition continues to increase.Therefore,appropriate measures should be adopted to mitigate species losses.
基金funded through the internal funds of the ICMR-VCRC,Puducherry,India
文摘Background Tick borne diseases are re-emerging around the world,including India.Information about the occurrence of the tick vectors in different geographical locations is essential for controlling the diseases.Tick surveys have not been conducted in many parts of India and information on the current prevalence of tick vectors is not available in all states of India.Many studies have been carried out utilizing modelling methods to predict the distribution of tick species in other countries.The MaxEnt model is widely used for predicting tick species distribution using bioclimatic variables.Lyme disease vectors such as Ixodes sp.,Amblyomma sp.,and Dermacentor sp.are the most commonly predicted tick species.However,very few studies have been carried out to predict the distribution of tick species in India.Haemaphysalis spinigera,the primary Kyasanur Forest Disease vector,was predicted along the Western Ghats using the MaxEnt model.Rhipicephalus(Boophilus)microplus was predicted across India using the generalized linear model(GLM).Identifying the tick vectors in transmitting the infection through conventional survey and identification methods is cumbersome due to the less number of experienced persons available.Prediction of tick vectors of public health concern,including other tick species in different geographical regions of Tamil Nadu,India,is essential for the prevention and control of tick-borne disease in humans and domestic animals.The present study adopts the package‘SSDM’(stacked species distribution models)with R software containing ensemble species distribution models to predict the distribution of tick species using different available environmental and climatic data.Results The categorical variables such as land use and land cover(LULC),soil type,elevation,Bio1,Bio10,Bio15,Bio19 and Bio8 contributed more to modelling the distribution of tick species.MaxEnt,GLM,GBM and GAM are suitable models for predicting the tick species distribution in the present study.Among these models,MaxEnt is the most suitable model for predicting tick species distribution in Tamil Nadu,India.Conclusions Our results suggest that MaxEnt is a suitable model for predicting the distribution of tick species.Both environmental factors such as LULC,elevation and soil type and bioclimatic factors such as temperature and precipitation contribute significantly to predicting tick species distribution in domestic animals in Tamil Nadu.The SSDM package is very useful and user-friendly graphical user interface for modelling the distribution of tick species.However,the package can be further improved by using higher resolution raster variables in larger areas,which is not currently supported.The predicted elevation range of Ha.spinigera distribution could not be provided due to software limitations.
基金a Project(WAMOS)funded by the Austrian Promotion Agency(FFG)within the program line“ASAP”(Project Number FO999900575)
文摘Background The impact of vessel-induced waves on macrophyte communities in lakes remains controversial,due to a lack of comprehensive assessments which also consider mechanistic effects on ecological processes during early life stages.This study investigates both the direct and indirect effects of such waves on the early life stages of macrophytes in a case study of Lake W?rthersee,Austria.The study focuses on Characeae species and Najas intermedia which have both experienced significant declines in Lake W?rthersee.Results The linear wave theory was applied to model typical small vessel-induced waves,characterized by wave heights of 0.05–0.30 m and periods of 1 and 3 s.Relevant characteristics for testing remobilization of oospores and seeds like geometric dimensions and density were experimentally determined by field data.Sediment samples from ten locations across six beach sites at depths ranging from 0.8 to 2.2 m were collected and analyzed for oospore presence and sediment texture.Results indicate that maximum wave scenarios can affect oospores and seeds directly by motion activation at water depths down to 3.75 m.Moderate wave scenarios,which are assumed to occur more frequently,can mobilize those particles between 0.75 and 2.25 m water depth.This corresponds to our field data,where 95%of oospores were found in samples from water depths≥2 m.The mobilization disrupts germination processes and impedes the recovery of macrophyte populations.Additionally,in the study lake and other fine-sediment dominated lakes,a significant fraction of sediments can be initiated to motion by small vessel-induced waves,which may indirectly affect germination by altering habitat conditions like turbidity and nutrients.However,grain size distribution showed minimal variation with depth at the same sampling sites,indicating limited sediment redistribution at the selected sampling sites by small vessel-induced waves.No significant correlation was found between oospore abundance and sediment grain size.Conclusions These findings suggest that the impacts of increased traffic of small vessels in lakes may be a key factor contributing to the decline of macrophyte species in shallow waters by motion triggering of oospores and seeds,with broader implications for the recreational management.
文摘Nutrient concentrations in foliage are often used to infer whether growth of a species at a particular site is likely limited by low supply of soil nutrients.Sometimes ratios of nutrient elements(stoichiometry)are thought to be useful,as if a higher supply of one element might somehow physiologically alleviate,or interfere with,a low supply of another.The growth of most forests is indeed commonly limited by low supplies of nutrients in soils,but foliar chemistry has proven unable to discern nutrient limitations.We illustrate this conclusion using two large,regional experiments with Eucalyptus in Brazil and loblolly pine(Pinus taeda L.)in the southeastern USA.In both cases,most sites showed profitable increases in growth after fertilization,and nutrient concentrations in foliage differed substantially across sites.However,foliar nutrient concentrations(and stoichiometric ratios)did not provide useful information about forest growth responses.We urge authors,reviewers,and editors not to expect foliar chemistry to be a useful tool for diagnosing nutrient limitations in forests,unless strong,local evidence demonstrates a reliable association.
基金funded by the Forestry Science and Technology Research and Innovation Project of China(grant no.XLKY202322)Joint Funds of National Natural Science Foundation of China(grant no.U21A20187)+6 种基金Key Research and Development Program of Hunan province(grant no.2023SK2055)National Key R&D Program of China(grant no.2020YFA0608100)Creative Research Groups of Provincial Natural Science Foundation of Hunan(grant no.2024JJ1016)Water Science and Technology Project of Hunan province(grant no.XSKJ2022068-35)Hunan Provincial Natural Science Foundation of China(grant no.2024JJ5639)Changsha Municipal Natural Science Foundation(grant no.kq2402249)Three Gorges follow-up project of the Ministry of Water Resources(grant no.HY110161A0012022)
文摘Background Biochar is widely recognized for its capacity to capture and store carbon in soil attributed to its stable structure. However, in most field studies examining the effects of biochar application on soil respiration, the impact of rainfall events on the experimental outcomes has not been taken into account. To address the existing gap in this research field, we conducted a one-year study on soil respiration in an urban camphor forest and collected the data of soil respiration, soil temperature, soil moisture, and the rainfall events closest to the soil respiration monitoring time. We specifically examined how different stages of rainfall events influenced soil respiration in relation to biochar application.Results This study found that the annual average soil respiration rate increased with the doses of biochar application, and the soil respiration rate under the biochar application at the dose of 45 t/ha showed a significant rise. The stages of rainfall events, rainfall amount, and the interaction effect of the two, and biochar doses significantly affected soil respiration. The parameters in the regression model for soil respiration, soil temperature and moisture varied with the different stages of rainfall events and the doses of biochar application. The biochar application eliminated the significant effect of soil moisture on soil respiration during one day after rainfall events. The significant correlation between soil moisture and the temperature sensitivity of soil respiration(Q10) was eliminated by biochar application, both during one day after rainfall events and more than eight days after rainfall events.Conclusions Our findings indicated that the rice straw biochar application has a short-term positive effect on soil respiration in urban camphor forests. The rainfall events affect the field soil respiration monitored in the biochar applications, possibly by affecting the soil respiration response to soil temperature and moisture under different doses of biochar application. The impact of rainfall events on soil respiration in biochar application experiments should be considered in future forest monitoring management and practice.
基金funded by Tenaga Nasional Berhad Research(TNBR)grant number ST-2022–019
文摘Background The increasing demand for large-scale hydroelectric dam development in tropical developing countries has led to significant land-use changes that impact biodiversity,particularly in megadiverse countries,such as Malaysia.Although many recent infrastructure projects incorporate sustainable concepts for wildlife monitoring and management,studies on the impacts of habitat fragmentation on ground-dwelling birds during the development phase remain scarce.This study aimed to assess the response of forest bird communities,particularly the ground-dwelling birds,across different phases of hydroelectric dam development using infrared camera traps.We collected data from 14 sampling sites in Nenggiri hydroelectric dam catchment area for 25 months across three developmental phases:pre-logging,logging,and construction.Results We recorded 1045 occurrences of 33 bird species,including the critically endangered Malayan Crestless Fireback Lophura erythrophthalma and the endangered Malayan Peacock-Pheasant Polyplectron malacense.There were significant changes between phases,with a notable decrease in the number of pheasants detected,such as the Great Argus Argusianus argus and Malayan Crested Fireback Lophura rufa,especially during the construction phase.Indicator species analysis(Ind Val)identified seven species showing strong associations(p<0.05)with specific development phases,including the Barred Cuckoo-Dove Macropygia unchall and Great Argus for the pre-logging phase.Conclusion These results highlight the vulnerability of ground-dwelling birds,particularly pheasants,to habitat disturbances from large-scale development activities.We propose incorporating camera trap assessments into major infrastructure projects to identify key locations of conservation-priority bird species,and to inform targeted rescue or translocation efforts,particularly during high-impact phases such as habitat clearance and dam impoundment.
基金financially supported by the Third Xinjiang Scientific Expedition Program(2022xjkk0404)the National Science&Technology Fundamental Resources Investigation Program of China(2019FY100601)the National Natural Science Foundation of China(W2412123,32271624,32271579 and 31670446)
文摘Background The changing hydrological conditions in wetland ecosystems are often accompanied by salt fluctuations.However,how fluctuating salt conditions affect growth and interspecific competition of dominant plants in wetlands remains unclear.This study aims to investigate the response of growth and competitive ability of a dominant species in inland salt marshes,Bolboschoenus planiculmis,under different salt conditions and test if B.planiculmis is more adapted to the fluctuating salt environments.Methods We quantified the growth indices and competitive response of B.planiculmis and two other dominant species Phragmites australis and Suaeda salsa under five salt treatments(control,constant Na Cl,constant mixed salt,pulsed increase of mixed salt,and fixed increase of mixed salt)and two competition treatments(no competition and interspecific competition)in a greenhouse experiment.Results We found that the total biomass of B.planiculmis was significantly higher under the mixed salt treatments compared to the Na Cl treatment,and was more advantageous than S.salsa in the mixed salt treatments when competing with it.Fluctuating mixed salt treatments significantly increased the total biomass of B.planiculmis more than the constant mixed salt treatment.Particularly,B.planiculmis benefited more than P.australis or S.salsa in competition.Moreover,the competitive response of B.planiculmis was stronger than the other two species in the fluctuating mixed salt treatments,although the biomass of B.planiculmis was lower than the other two species.Conclusion Our results demonstrated that fluctuating salt conditions prioritized interspecific competition of B.planiculmis.We support the competition-to-stress hypothesis that the competition ability rather than salt stress tolerance was the main determinant of species survival in fluctuating salt with a less stressful survival condition.Our study provides important information in understanding community composition changes and restoration of degraded salt marshes.
基金supported by the National Natural Science Foundation of China Joint Fund Project(U21A20186)the International Cooperation Project of Key Research and Development and Transformation in Qinghai Province(2024-HZ-810)+1 种基金the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0302)the project of“No-till replanting technology to promote the production and ecological function of heavily degraded alpine grasslands”(QLC2024TG14)
文摘Background Soil respiration(Rs)is critical for maintaining the terrestrial carbon(C)cycling,and considerable research has focused on its response to climate warming.However,our knowledge of the mechanistic basis of the plant functional composition on Rs is limited.We conducted a 2-year field warming experiment to explore Rs responses to different warming levels across three types of alpine grasslands:alpine steppe(AS)dominated by grasses,alpine meadow(AM)and alpine swamp meadow(ASM),both of the latter two dominated by sedges.Results Our findings revealed contrasting effects of warming on Rs across three alpine grassland types:minimal change in the AS,a significant 24%increase in the AM,and a 20%decrease in the ASM.Dominant plant functional groups in each grassland type play an important role in regulating the response of Rs to warming.Moreover,we found a negative correlation between plant height and Rs in the grass-dominated AS and sedge-dominated AM.However,there was no correlation between plant height and Rs in ASM.Furthermore,Rs was regulated by both soil moisture and soil temperature,while in ASM it was constrained by soil moisture levels.Conclusions Our results underscore the importance of incorporating plant functional composition mechanisms when assessing ecosystem C balance under climate warming.Future studies should consider the ecosystem-specific characteristics when investigating the connections between plant community structure,traits,and ecosystem function.
