In recent years,many studies have focused on the effects of global climate warming and increased nitrogen deposition on the structure and function of grassland ecosystem.However,there are still significant uncertainti...In recent years,many studies have focused on the effects of global climate warming and increased nitrogen deposition on the structure and function of grassland ecosystem.However,there are still significant uncertainties in the response mechanism of stability of plant community biomass in alpine meadows of the Qinghai-Xizang Plateau,China to these two major climate factors.Given this,based on field control experiments,this study systematically evaluated the effects of different levels of climate warming(W0(no warming),W1(air temperature increased by 0.47℃ or soil temperature increased by 0.61℃),W2(air temperature increased by 0.92℃ or soil temperature increased by 1.09℃),W3(air temperature increased by 1.44℃ or soil temperature increased by 1.95℃)),nitrogen deposition(N0(0 kg N/(hm^(2)·a)),N16(16 kg N/(hm^(2)·a)),and N32(32 kg N/(hm^(2)·a))),and their interactions on plant community biomass and its temporal stability,and explored its potential regulatory mechanisms.The results showed that the biomass of total community,Gramineae,and dominant species increased significantly with increasing temperature,but the biomass of common and rare species decreased significantly.Nitrogen deposition also significantly promoted the biomass accumulation of community and gramineous plants.Under the treatment of W3N32,the biomass of plant community,Gramineae,and dominant species reached the highest values,indicating that there was a synergistic effect under this treatment.Structural equation model showed that increasing temperature significantly decreased the stability of plant community biomass by reducing the stability of grass and dominant species biomass and weakening species asynchronism.Interaction of increased nitrogen deposition and temperature increased the biomass fluctuation of grass functional group,thus amplifying its negative influence on community stability.More attention should be paid to the response and regulatory mechanisms of dominant species and functional groups under global climate change.This study provides a theoretical basis for revealing the stability maintenance mechanism of alpine grassland and also provides scientific support for the development of future grassland ecosystem management and assessment.展开更多
The concept of plant community and community classification were expatiated, the study history and actuality were summarized, and the developmental trends of phytocoenology were prospected.
This paper reports a geomorphologic landscape investigation, vegetationsurvey and soil sampling at 14 sites across the Gurbantunggut Desert between87°37′09″-88°24′04″E and 44°14′04″-45°41′52...This paper reports a geomorphologic landscape investigation, vegetationsurvey and soil sampling at 14 sites across the Gurbantunggut Desert between87°37′09″-88°24′04″E and 44°14′04″-45°41′52″N. The study encountered 8 species of lowtrees and shrubs, 5 of perennial herbs, 8 of annual plants and 48 of ephemeral and ephemeroidplants. These species of plants represent one-third of the species found in the GurbantunggutDesert, and their communities make up a large proportion of desert vegetation with great landscapesignificance. In the investigation we found that the plant communities are accordingly succeededwith the spatial variation of macro-ecoenvironment. Using Principal Component Analysis (PCA) andCorrelation Analysis (CA) we found that the micro-ecoenvironment heterogeneity of aeolian sandysoil's physical and chemical properties such as soil nutrient, soil moisture, soil salt, pH etc.only impacted the diversity of herb synusia (PIEherb) of the desert, with a negative correlation.Meanwhile, the impact of microhabitat on the plant community pattern with an antagonisticinteraction made vegetation's eco-distribution in a temporary equilibrium.展开更多
Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate th...Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate that the amount of elements from litter decomposition was less than that of the plant uptake from soil, but that from plant uptake was higher than that in soil with mineralization process released. On the other hand, in the open system including precipitation input and soil leaching output, because of great number of elements from precipitation into the open system, the element cycling(except N, P) in the Alpine tundra ecosystem was in a dynamic balance. In this study, it was also found that different organ of plants had significant difference in accumulating elements. Ca, Mg, P and N were accumulated more obviously in leaves, while Fe was in roots. The degree of concentration of elements in different tissues of the same organ of the plants also was different, a higher concentration of Ca, Mg, P and N in mesophyll than in nerve but Fe was in a reversed order. The phenomenon indicates (1) a variety of biochemical functions of different elements, (2) the elements in mesophyll were with a shorter turnover period than those in nerve or fibre, but higher utilization rate for plant. Therefore, this study implies the significance of keeping element dynamic balance in the alpine tundra ecosystem of Changbai Mountains.展开更多
We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia to determine plant community types and species distribution patterns and their relationships...We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia to determine plant community types and species distribution patterns and their relationships with environmental variables, including altitude, pH, cation exchange capacity, electrical conductivity （EC）, and moisture. We used a selective approach with a systematic sampling design. A total of 74 quadrats, each 25m × 25m at intervals of 150-200 m were sampled along the established transect lines. For herbaceous vegetation and soil data collection, five subquadrats each lm x lm were established at the four corners and the center of each quadrat. Three community types were identified using TWINSPAN analysis. All three community types showed high diversity （Shannon-Weiner index）, the highest in community type II at 3.55. The highest similarity coefficient was 0.49 （49%） between community types II and III, reflecting 0.51 （51%） dissimilarity in their species richness. The canonical correspondence ordination diagram revealed that the distribution pattern of community type I was explained by moisture while that of community types III and II was explained by EC and altitude and moisture, respectively. Altitude was the most statistically significant environmental variable, followed by moisture and EC in determining the total variation in species composition and distribution patterns while pH and cation exchange capacity were non significant. In conclusion, we recommend that any intervention should take into account these three discrete community types and their environmental settings to make the intervention more successful.展开更多
Topography and soil factors are known to play crucial roles in the species composition of plant communities in subtropical evergreen-deciduous broadleaved mixed forests.In this study,we used a systematic quantitative ...Topography and soil factors are known to play crucial roles in the species composition of plant communities in subtropical evergreen-deciduous broadleaved mixed forests.In this study,we used a systematic quantitative approach to classify plant community types in the subtropical forests of Hubei Province(central China),and then quantified the relative contribution of drivers responsible for variation in species composition and diversity.We classified the subtropical forests in the study area into 12 community types.Of these,species diversity indices of three communities were significantly higher than those of others.In each community type,species richness,abundance,basal area and importance values of evergreen and deciduous species were different.In most community types,deciduous species richness was higher than that of evergreen species.Linear regression analysis showed that the dominant factors that affect species composition in each community type are elevation,slope,aspect,soil nitrogen content,and soil phosphorus content.Furthermore,structural equation modeling analysis showed that the majority of variance in species composition of plant communities can be explained by elevation,aspect,soil water content,litterfall,total nitrogen,and total phosphorus.Thus,the major factors that affect evergreen and deciduous species distribution across the 12 community types in subtropical evergreendeciduous broadleaved mixed forests include elevation,slope and aspect,soil total nitrogen content,soil total phosphorus content,soil available nitrogen content and soil available phosphorus content.展开更多
Methane(CH_(4))is an important greenhouse gas second only to CO_(2)in terms of its greenhouse effect.Vegetation plays an important role in controlling soil CH_(4)fluxes,but the spatial variability of soil CH_(4)fluxes...Methane(CH_(4))is an important greenhouse gas second only to CO_(2)in terms of its greenhouse effect.Vegetation plays an important role in controlling soil CH_(4)fluxes,but the spatial variability of soil CH_(4)fluxes during vegetation restoration in Loess Hilly Region(LHR)is not fully understood.The effects of different plant community types[Medicago sativa grassland(MS);Xanthoceras sorbifolium forestland(XS);Caragana korshinskii bushland(CK);Hippophae rhamnoides shrubland(HR);and Stipa bungeana grassland(SB)]on soil CH_(4)flux in LHR were studied via the static chamber technique.The results showed that the five plant community types were sinks of soil CH_(4)in LHR,the plant community type significantly affected the soil CH_(4)flux,and the average CH_(4)uptake from high to low was in SB,HR,CK,MS,and XS.During the whole study period,the soil CH_(4)flux showed similar interannual variation.The maximum absorption of soil CH_(4)appeared in the growing season,while the minimum appeared in winter.Soil CH_(4)uptake was positively correlated with soil temperature and soil moisture.Soil temperature and moisture are important controlling factors for the temporal variability of soil CH_(4)flux.In LHR,the Stipa bungeana grassland is the more suitable plant community type for reducing soil CH_(4)emissions.In the process of vegetation restoration in LHR,the soil CH_(4)absorption potential of different plant community types should be considered,ecological benefits should be taken into account,and vegetation more suitable for mitigating the greenhouse effect should be selected.展开更多
Background:Seed dispersal by scatter-hoarding animals can affect the developmental dynamics of plant communities.However,how animals might participate in plant inter-community competition has rarely been investigated....Background:Seed dispersal by scatter-hoarding animals can affect the developmental dynamics of plant communities.However,how animals might participate in plant inter-community competition has rarely been investigated.Forest community junction is an area where the competition between plant communities is most prominent and animal activity is more frequent.At present,little is known about how scatter-hoarding animals might assist competitions by adjacent plant communities.Thus,for 3 years(2015–2017),we tracked the fate of 2880 tagged seeds(Quercus aliena var.acuteserrata,Pinus tabuliformis,and P.armandii seed)placed near an edge where the forest composition changes from a pine forest to an oak forest in northwestern China.Results:We found that the seed fates differed when Quercus and Pinus seeds entered adjacent stands.In contrast to Pinus seeds,acorns that entered pine forests were characterized by higher caching rates and longer dispersal distances.Pinus seeds had the highest probability of being predated(85%)by rodents,and eleven Q.aliena var.acuteserrata seedlings were established in pine forests,although none survived in the later stages.In addition,rodents exhibited obvious selectivity in terms of the microhabitats for the seed caching sites.Conclusions:Seed fates differed when Quercus and Pinus seeds entered adjacent stands.The predation pressure by rodents on the seeds of Pinus species limited the germination of seeds and seedling establishment in oak forests.The different seed fates after their bidirectional dispersal could affect the differences in natural regeneration between pine and oak forests,and they might increase the recruitment rates for oak at the edge of an adjacent community.Rodent-mediated seed dispersal could potential unintentionally affect the competition between plant communities.展开更多
The change of plant community character during recovery succession processes of high mountain meadow in Naqu, Tibet, was investigated. The results show that there are 41 plant species in the inventoried quadrates. The...The change of plant community character during recovery succession processes of high mountain meadow in Naqu, Tibet, was investigated. The results show that there are 41 plant species in the inventoried quadrates. The high-plants in four big families plays important roles in natural vegetation recovery, while Kobresia play an important role in climax communities. The plant species components changed with each succession stage. The plant species were mainly annual and biennial during the early succession stage, and perennial during the medium; and dominated by Kobresia humilis during the late. Potentilla bifurca and Potentilla tanaletfolia were both found in all stages. The accumulated number of family, genus, and species during the succession process varied quadric with the stages. The main plant community characteristics varied logistically with the succession stages except the height. The community characteristics mainly affected by dominant species which were changed in same rhythms. The biomass under ground was far more than the upground. The plant diversity inflated in the medium stage.展开更多
[Objective] To investigate the relationship between the grassland caterpillar with different grades and the structure of alpine Kobresia meadow or soil feature. [Method] A total of 10 plots （20.00 m × 20.00 m） ...[Objective] To investigate the relationship between the grassland caterpillar with different grades and the structure of alpine Kobresia meadow or soil feature. [Method] A total of 10 plots （20.00 m × 20.00 m） were chosen. In each plot, five smaller plots （5.00 m × 5.00 m） were randomly selected and six sample plots （0.25 m × 0.25 m） were then selected in each smaller plot. The biomass, vegetation height, grasslayer thickness, bare land area, soil moisture and total vegetation cover degree were determined. Data were analyzed statistically by Excel 2003 and SPSS 13.0 software. [ Result] There was a significant difference （P 〈 0.05） between the grassland caterpillars at different hazard grades and the structure of alpine Kobresia meadow or soil properties. [ Conclusion] With the increase of grassland caterpillar density, the plant community structure of alpine Kobresia meadows changes from sedge family-dominant community to the forbs-dominant community.展开更多
[Objectives] This study was conducted to explore the characteristics of natural grassland plant communities in the National Photovoltaic and Energy Storage Empirical Experiment Platform(Daqing Base), so as to provide ...[Objectives] This study was conducted to explore the characteristics of natural grassland plant communities in the National Photovoltaic and Energy Storage Empirical Experiment Platform(Daqing Base), so as to provide data reference for local grassland resources. [Methods] June to July, 2022, standard plot site investigation was carried out to investigate vegetation species, relative height, relative coverage, relative abundance, relative frequency and dominance in the National Photovoltaic and Energy Storage Empirical Experiment Platform in Datong District, Daqing City of Heilongjiang Province, and to analyze plant community structures in the photovoltaic DC field. [Results] The photovoltaic DC field contained 22 species of plants, of which Suaeda salsa was the common species. The dominant species in photovoltaic DC field were Leymus chinensis, Eleocharis intersita, Carex duriuscula and Carex rugurosa. [Conclusions] The dominant vegetation types were Poaceae and Cyperaceae in the natural grassland of the National Photovoltaic and Energy Storage Empirical Experiment Platform(Daqing Base).展开更多
A sand-accumulation belt came into being during the process of desert control in recent 60 years at the edge of oasis,especially at the upwind places in desert area in Hexi Corridor of Gansu.Among them,the sand-accumu...A sand-accumulation belt came into being during the process of desert control in recent 60 years at the edge of oasis,especially at the upwind places in desert area in Hexi Corridor of Gansu.Among them,the sand-accumulation belt at the edge of Minqin Oasis is relatively typical and the most complete.The vegetation on the sand-accumulation belt is not only the formation factor of the sand-accumulation belt,but also an important factor to maintain the stability of the sand-accumulation belt.In a certain sense,the health status of the vegetation of the sand-accumulation belt determines the stability of the sand-accumulation belt.In order to analyze the vegetation status of the sand-accumulation belt,the health sequence analysis of the plant community was carried out of sand-accumulation belt at the edge of Minqin Oasis,by setting 11 lines of equal spacing of sand-accumulation belt at the edge of Minqin Oasis,and through the vegetation survey of more than 60 samples.The vegetation on the sand-accumulation belt at the edge of Minqin Oasis is generally unhealthy.But for the health sequence of this study,the health status of vegetation of the sand-accumulation belt formed by artificial sand fixation forest is better than that of vegetation of the sand-accumulation belt formed by natural shrub at the edge of Minqin Oasis.The health status of vegetation of the sand-accumulation belt of mixed forest of arbor and shrub is the worst at the edge of Minqin Oasis.The dominant species Tamarix laxa on the sand-accumulation belt in the lower reaches of the oasis are seriously withered,and their health is the worst.There is potential danger of the sand-accumulation belt being blown and activated.After abandonment of farmland,protection of protection forest and sand-accumulation belt at the edge of farmland in sand area is a new problem,which is worth considering.展开更多
The overexploitation of the natural environment caused by urbanization makes more and more natural and semi-natural plant communities gradually lack,which causes a lot of irreversible damage to the environment.Therefo...The overexploitation of the natural environment caused by urbanization makes more and more natural and semi-natural plant communities gradually lack,which causes a lot of irreversible damage to the environment.Therefore,it is very important to carry out ecological environment construction in all fields of urban construction.In this paper,based on theory and method of plant landscape construction under the concept of"nearly natural"plant community,through the investigation and analysis on plant species,distribution,and structural characteristics of plant community in Baguang District of Shenzhen,regional native plant species are summarized,and structural characteristics of original zonal plant community are simulated.The research aims to provide a reference basis for creating a coastal plant landscape with subtropical marine climate for Baguang and even Lingnan,constructing near natural ecological park according to local conditions,forming the pattern well-coordinated with the local natural ecosystem,and carrying out protection of the regional ecological environment.展开更多
To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in Apr...To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in April 2009, and TM (30 m) data in 2006, the composition and characteristics of natural plants community in different time of the Fengxian area in the Changjiang (Yangtze) River estuary were analyzed with two-way indicator species analysis (TWINSPAN), multivariate analysis of variance (MANOVA), detrended canonical correspondence analysis (DCCA) and canonical correspondence analysis (CCA). The results show that: 1) The plant communities in the reclaimed area are mainly mesophytes and helophytic-mesophytic transitional communities, showing a gradient distribution trend with the change in reclamation years. Species richness (MA), species diversity (H) and above-ground biomass also increase with the increase of reclamation years. Nevertheless, they appear to decline slightly in the middle and late reclamation period (> 30 years). 2) With the rise in land use levels, the changes in species richness and species diversity tend to increase at first and then decrease; species dominance (D), however, tends to decline; and above-ground biomass increases slightly. 3) The distribution of the plant community is mainly influenced by the following factors: land use levels (R = 0.55, p < 0.05), soil moisture (R = 0.53, p < 0.05), soil salinity (R = 0.43, p < 0.05) and reclamation time (R = 0.40, p < 0.05).展开更多
The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics...The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events,vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter's variance ratio, pearson's chi-squared test, Spearman's correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups.This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing,and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area.展开更多
Urban green spaces have positive effects on both physical and mental wellbeing.However,few studies have focused on the trends and thresholds of the effects of different influences on restorative benefits when viewing ...Urban green spaces have positive effects on both physical and mental wellbeing.However,few studies have focused on the trends and thresholds of the effects of different influences on restorative benefits when viewing scenes differfeaturing plant communities.We measured subjective evaluations and objective physiological data from 44 participants who viewed images of plant communities in the yellow to green hue range to compare differences in restorative benefits among plant communities at different visual distances,as well as quantifying the influencing factors involved.The following results were found:(1)Coniferous and multi-layered plant communities were found to provide greater restorative benefits,and the restorative benefits grew with increasing visual distance.(2)Shape and color characteristics were significantly correlated with restorative benefits,but the relationship is not simply linear.(3)The restorative benefits were found to be greatest when crown proportion was 61.23%,trunk proportion ranged from 4.11%to 13.70%,and the value of color index value ranged from 25.44%to 35.56%;the restorative benefits gradually increased when sky proportion exceeded 12.95%-13.19%,the fractal dimension exceeded 1.62-1.67,and hue index exceeded 91.64°-95.67°;additionally,the restorative benefits decreased when the saturation index increased.This study provides a scientific basis for the construction and improvement of plant landscapes in urban green spaces.展开更多
Livestock farming is a critical pillar of Tajikistan’s national economy and livelihood security.However,significant economic challenges in the country have led to the degradation of grassland ecosystems.This degradat...Livestock farming is a critical pillar of Tajikistan’s national economy and livelihood security.However,significant economic challenges in the country have led to the degradation of grassland ecosystems.This degradation has not only reduced the productivity of grassland ecosystems but also severely impacted their ecological functions.A particularly concerning consequence is the threat to biodiversity,as the survival and persistence of endemic,rare,and endangered plant species are at serious risk,thereby diminishing the value of species’genetic resources.Based on the data from multiple sources such as literature reviews,field observations,and national statistics,this study employed a systematic literature review and meta-analysis to investigate the current status,causes of degradation,and restoration measures for grassland ecosystems in Tajikistan.The results revealed that Tajikistan’s grassland ecosystems support exceptionally high plant species diversity,comprising over 4500 vascular plant species,including nearly 1500 endemic and sub-endemic taxa that constitute a unique genetic reservoir.These ecosystems are experiencing severe degradation,characterized by significantly reduced vegetation cover and declining species richness.Palatable forage species are increasingly being displaced by unpalatable,thorny,and poisonous species.The primary drivers of degradation include excessive grazing pressure,which disrupts plant reproductive cycles and regeneration capacity,habitat fragmentation due to urbanization and infrastructure development,and uncontrolled exploitation of medicinal and edible plants.Climate change,particularly rising temperatures and altered precipitation patterns,further exacerbates these anthropogenic pressures.Ecological restoration experiments suggested that both ecosystem productivity and plant species diversity are significantly enhanced by systematic reseeding trials using altitude-adapted native species.These findings underscore the necessity of establishing scientifically grounded approaches for ecological restoration.展开更多
Understory plants are an integral part of forests,serving a variety of functions that help maintain healthy ecosystems.The structure and composition of the understory are influenced by numerous biotic and abiotic fact...Understory plants are an integral part of forests,serving a variety of functions that help maintain healthy ecosystems.The structure and composition of the understory are influenced by numerous biotic and abiotic factors,with light being critical.The introduction of the pathogen Cronartium ribicola,which causes white pine blister rust,into North America in the early 20 th century led to the near total loss of western white pine(Pinus monticola)from moist forests of the Northern Rockies.Management is reintroducing blister rust-resistant western white pine across the landscape,but the effects on the understory are unknown.We examined the effects of stand structure and proportion of western white pine in the overstory on understory diversity of vascular plants in closed canopy stands dominated by blister rust-resistant western white pine across northern Idaho.Habitat series explained the greatest amount of variation(34%)in species presence-absence,while canopy cover accounted for 25%,basal area of all trees for 18%,and the proportion of western white pine composition by 14%.Our analysis revealed positive relationships between the proportion of western white pine in the overstory and both the presence of understory plants and the cover of several understory species.For both the presence and cover,separate sets of thirteen species were found to have a positive relationship with the proportion of western white pine in the overstory,with eight species in common.This research fills a knowledge gap by using data from a range of stands across northern Idaho with varying abundance of western white pine in the overstory to evaluate the relationship between the understory and overstory composition.As land managers plant more western white pine trees,we are likely to see the concomitant increase in understory plant diversity across the landscape,in addition to numerous other benefits,including disturbance resistance and resilience.展开更多
For more than a century, ecologists have concentrated on competition as a crucial process for community organization. However, more recent experimental investigations have uncovered the striking Influence of positive ...For more than a century, ecologists have concentrated on competition as a crucial process for community organization. However, more recent experimental investigations have uncovered the striking Influence of positive Interactions on the organization of plant communities. Complex combinations of competition and positive interactions operating simultaneously among plant species seem to be widespread In nature. In the present paper, we reviewed the mechanism and ecological importance of positive Interactions In plant communities, emphasizing the certainties and uncertainties that have made It an attractive area of research. Positive Interactions, or facilitation, occur when one species enhances the survival, growth, or richness of another. The Importance of facilitation in plant organization increases with ablotlc stress and the relative Importance of competition decreases. Only by combining plant interactions and the many fields of biology can we fully understand how and when the positive Interactions occur.展开更多
A better understanding the mechanisms driving plant biomass allocation in different ecosystems is an important theoretical basis for ilustrating the adaptive strategies of plants.To date,the effects of habitat conditi...A better understanding the mechanisms driving plant biomass allocation in different ecosystems is an important theoretical basis for ilustrating the adaptive strategies of plants.To date,the effects of habitat conditions on plant biomass allocation have been widely studied.However,it is less known how plant community traits and functions(PCTF)affect biomass allocation,particularly in alpine grassland ecosystems.In this study,community-weighted means(CWM)were calculated at the community level using five leaf functional traits,and the relationships between PCTF and biomass trade-offs were explored using correlation analysis,variation partitioning analysis and structural equation modeling.We found that the trade-off values were greater than zero in both alpine meadow(AM)and alpine steppe(AS)across the Tibetan Plateau,with different values of 0.203 and 0.088 for AM and AS,respectively.Moreover,the critical factors determining biomass allocation in AS were species richness(SR;scored at 0.69)and leaf dry matter content of CWM(CWM_(LDMC),scored at 0.42),while in AM,the key factors were leaf dry matter content(CWM.pMC scored at 0.48)and leaf carbon content of CWM(CWM_(LC),scored at-0.45).In particular,both CWM_(LDMC)and SR in AS,as well as CWM_(LDMC)and CWM_(LDMC)in AM were primarily regulated by precipitation.In summary,precipitation tends to drive biomass allocation in alpine grasslands through its effects on PCTF,hence highlighting the importance of PCTF in regulating plant biomass allocation strategies along precipitation gradients.展开更多
基金supported by the Key Research and Development and Transformation Plan of Qinghai Provincial Science and Technology Department(2024-NK-137)the Qinghai Province Science and Technology Commissioner Special Project(2024-NK-P28).
文摘In recent years,many studies have focused on the effects of global climate warming and increased nitrogen deposition on the structure and function of grassland ecosystem.However,there are still significant uncertainties in the response mechanism of stability of plant community biomass in alpine meadows of the Qinghai-Xizang Plateau,China to these two major climate factors.Given this,based on field control experiments,this study systematically evaluated the effects of different levels of climate warming(W0(no warming),W1(air temperature increased by 0.47℃ or soil temperature increased by 0.61℃),W2(air temperature increased by 0.92℃ or soil temperature increased by 1.09℃),W3(air temperature increased by 1.44℃ or soil temperature increased by 1.95℃)),nitrogen deposition(N0(0 kg N/(hm^(2)·a)),N16(16 kg N/(hm^(2)·a)),and N32(32 kg N/(hm^(2)·a))),and their interactions on plant community biomass and its temporal stability,and explored its potential regulatory mechanisms.The results showed that the biomass of total community,Gramineae,and dominant species increased significantly with increasing temperature,but the biomass of common and rare species decreased significantly.Nitrogen deposition also significantly promoted the biomass accumulation of community and gramineous plants.Under the treatment of W3N32,the biomass of plant community,Gramineae,and dominant species reached the highest values,indicating that there was a synergistic effect under this treatment.Structural equation model showed that increasing temperature significantly decreased the stability of plant community biomass by reducing the stability of grass and dominant species biomass and weakening species asynchronism.Interaction of increased nitrogen deposition and temperature increased the biomass fluctuation of grass functional group,thus amplifying its negative influence on community stability.More attention should be paid to the response and regulatory mechanisms of dominant species and functional groups under global climate change.This study provides a theoretical basis for revealing the stability maintenance mechanism of alpine grassland and also provides scientific support for the development of future grassland ecosystem management and assessment.
文摘The concept of plant community and community classification were expatiated, the study history and actuality were summarized, and the developmental trends of phytocoenology were prospected.
基金Xinjiang Uygur Autonomous Region′s Natural Science Foundation Project，The special support project from the Director′s fund of the Xinjiang Institute of Ecology and Geology，国家自然科学基金
文摘This paper reports a geomorphologic landscape investigation, vegetationsurvey and soil sampling at 14 sites across the Gurbantunggut Desert between87°37′09″-88°24′04″E and 44°14′04″-45°41′52″N. The study encountered 8 species of lowtrees and shrubs, 5 of perennial herbs, 8 of annual plants and 48 of ephemeral and ephemeroidplants. These species of plants represent one-third of the species found in the GurbantunggutDesert, and their communities make up a large proportion of desert vegetation with great landscapesignificance. In the investigation we found that the plant communities are accordingly succeededwith the spatial variation of macro-ecoenvironment. Using Principal Component Analysis (PCA) andCorrelation Analysis (CA) we found that the micro-ecoenvironment heterogeneity of aeolian sandysoil's physical and chemical properties such as soil nutrient, soil moisture, soil salt, pH etc.only impacted the diversity of herb synusia (PIEherb) of the desert, with a negative correlation.Meanwhile, the impact of microhabitat on the plant community pattern with an antagonisticinteraction made vegetation's eco-distribution in a temporary equilibrium.
基金The National Natural Science Foundation of China(No. 90211003) and the Innovation Program of the Chinese Acdemy of Sciences(No. KZCX3 SW 332)
文摘Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate that the amount of elements from litter decomposition was less than that of the plant uptake from soil, but that from plant uptake was higher than that in soil with mineralization process released. On the other hand, in the open system including precipitation input and soil leaching output, because of great number of elements from precipitation into the open system, the element cycling(except N, P) in the Alpine tundra ecosystem was in a dynamic balance. In this study, it was also found that different organ of plants had significant difference in accumulating elements. Ca, Mg, P and N were accumulated more obviously in leaves, while Fe was in roots. The degree of concentration of elements in different tissues of the same organ of the plants also was different, a higher concentration of Ca, Mg, P and N in mesophyll than in nerve but Fe was in a reversed order. The phenomenon indicates (1) a variety of biochemical functions of different elements, (2) the elements in mesophyll were with a shorter turnover period than those in nerve or fibre, but higher utilization rate for plant. Therefore, this study implies the significance of keeping element dynamic balance in the alpine tundra ecosystem of Changbai Mountains.
基金supported by Special Fund for Public Welfare Technology Research of Agricultural Industry (200903014)
文摘We studied woodland vegetation in broad-leaved deciduous woodlands of Metema in northwestern Amhara regional state, Ethiopia to determine plant community types and species distribution patterns and their relationships with environmental variables, including altitude, pH, cation exchange capacity, electrical conductivity （EC）, and moisture. We used a selective approach with a systematic sampling design. A total of 74 quadrats, each 25m × 25m at intervals of 150-200 m were sampled along the established transect lines. For herbaceous vegetation and soil data collection, five subquadrats each lm x lm were established at the four corners and the center of each quadrat. Three community types were identified using TWINSPAN analysis. All three community types showed high diversity （Shannon-Weiner index）, the highest in community type II at 3.55. The highest similarity coefficient was 0.49 （49%） between community types II and III, reflecting 0.51 （51%） dissimilarity in their species richness. The canonical correspondence ordination diagram revealed that the distribution pattern of community type I was explained by moisture while that of community types III and II was explained by EC and altitude and moisture, respectively. Altitude was the most statistically significant environmental variable, followed by moisture and EC in determining the total variation in species composition and distribution patterns while pH and cation exchange capacity were non significant. In conclusion, we recommend that any intervention should take into account these three discrete community types and their environmental settings to make the intervention more successful.
基金the National Natural Science Foundation of China(51809250)Hubei Provincial Natural Science Foundation for Innovation Groups(No.2019CFA019).
文摘Topography and soil factors are known to play crucial roles in the species composition of plant communities in subtropical evergreen-deciduous broadleaved mixed forests.In this study,we used a systematic quantitative approach to classify plant community types in the subtropical forests of Hubei Province(central China),and then quantified the relative contribution of drivers responsible for variation in species composition and diversity.We classified the subtropical forests in the study area into 12 community types.Of these,species diversity indices of three communities were significantly higher than those of others.In each community type,species richness,abundance,basal area and importance values of evergreen and deciduous species were different.In most community types,deciduous species richness was higher than that of evergreen species.Linear regression analysis showed that the dominant factors that affect species composition in each community type are elevation,slope,aspect,soil nitrogen content,and soil phosphorus content.Furthermore,structural equation modeling analysis showed that the majority of variance in species composition of plant communities can be explained by elevation,aspect,soil water content,litterfall,total nitrogen,and total phosphorus.Thus,the major factors that affect evergreen and deciduous species distribution across the 12 community types in subtropical evergreendeciduous broadleaved mixed forests include elevation,slope and aspect,soil total nitrogen content,soil total phosphorus content,soil available nitrogen content and soil available phosphorus content.
基金financially supported by the Gansu Province Key Research and Development Program (Grant No. 20YF8NA135)the Gansu Province Financial Special Project (Grant No. GSCZZ 20160909)the Industrial Support Program Project (Grant No. 2021CYZC15, No.2022CYZC-41)
文摘Methane(CH_(4))is an important greenhouse gas second only to CO_(2)in terms of its greenhouse effect.Vegetation plays an important role in controlling soil CH_(4)fluxes,but the spatial variability of soil CH_(4)fluxes during vegetation restoration in Loess Hilly Region(LHR)is not fully understood.The effects of different plant community types[Medicago sativa grassland(MS);Xanthoceras sorbifolium forestland(XS);Caragana korshinskii bushland(CK);Hippophae rhamnoides shrubland(HR);and Stipa bungeana grassland(SB)]on soil CH_(4)flux in LHR were studied via the static chamber technique.The results showed that the five plant community types were sinks of soil CH_(4)in LHR,the plant community type significantly affected the soil CH_(4)flux,and the average CH_(4)uptake from high to low was in SB,HR,CK,MS,and XS.During the whole study period,the soil CH_(4)flux showed similar interannual variation.The maximum absorption of soil CH_(4)appeared in the growing season,while the minimum appeared in winter.Soil CH_(4)uptake was positively correlated with soil temperature and soil moisture.Soil temperature and moisture are important controlling factors for the temporal variability of soil CH_(4)flux.In LHR,the Stipa bungeana grassland is the more suitable plant community type for reducing soil CH_(4)emissions.In the process of vegetation restoration in LHR,the soil CH_(4)absorption potential of different plant community types should be considered,ecological benefits should be taken into account,and vegetation more suitable for mitigating the greenhouse effect should be selected.
基金the National Natural Science Foundation of China(No.31470644).
文摘Background:Seed dispersal by scatter-hoarding animals can affect the developmental dynamics of plant communities.However,how animals might participate in plant inter-community competition has rarely been investigated.Forest community junction is an area where the competition between plant communities is most prominent and animal activity is more frequent.At present,little is known about how scatter-hoarding animals might assist competitions by adjacent plant communities.Thus,for 3 years(2015–2017),we tracked the fate of 2880 tagged seeds(Quercus aliena var.acuteserrata,Pinus tabuliformis,and P.armandii seed)placed near an edge where the forest composition changes from a pine forest to an oak forest in northwestern China.Results:We found that the seed fates differed when Quercus and Pinus seeds entered adjacent stands.In contrast to Pinus seeds,acorns that entered pine forests were characterized by higher caching rates and longer dispersal distances.Pinus seeds had the highest probability of being predated(85%)by rodents,and eleven Q.aliena var.acuteserrata seedlings were established in pine forests,although none survived in the later stages.In addition,rodents exhibited obvious selectivity in terms of the microhabitats for the seed caching sites.Conclusions:Seed fates differed when Quercus and Pinus seeds entered adjacent stands.The predation pressure by rodents on the seeds of Pinus species limited the germination of seeds and seedling establishment in oak forests.The different seed fates after their bidirectional dispersal could affect the differences in natural regeneration between pine and oak forests,and they might increase the recruitment rates for oak at the edge of an adjacent community.Rodent-mediated seed dispersal could potential unintentionally affect the competition between plant communities.
文摘The change of plant community character during recovery succession processes of high mountain meadow in Naqu, Tibet, was investigated. The results show that there are 41 plant species in the inventoried quadrates. The high-plants in four big families plays important roles in natural vegetation recovery, while Kobresia play an important role in climax communities. The plant species components changed with each succession stage. The plant species were mainly annual and biennial during the early succession stage, and perennial during the medium; and dominated by Kobresia humilis during the late. Potentilla bifurca and Potentilla tanaletfolia were both found in all stages. The accumulated number of family, genus, and species during the succession process varied quadric with the stages. The main plant community characteristics varied logistically with the succession stages except the height. The community characteristics mainly affected by dominant species which were changed in same rhythms. The biomass under ground was far more than the upground. The plant diversity inflated in the medium stage.
基金funded by the grants from Basic Science and Research Special Fund for the State Level and Public Scientific Research Institute (Grassland Research Institute,Chinese Academy of Agricultural Sciences) and Wild Science Observation Testing Station of Alpine Meadow Grassland Resource and Ecotope of the Ministry of Agriculture
文摘[Objective] To investigate the relationship between the grassland caterpillar with different grades and the structure of alpine Kobresia meadow or soil feature. [Method] A total of 10 plots （20.00 m × 20.00 m） were chosen. In each plot, five smaller plots （5.00 m × 5.00 m） were randomly selected and six sample plots （0.25 m × 0.25 m） were then selected in each smaller plot. The biomass, vegetation height, grasslayer thickness, bare land area, soil moisture and total vegetation cover degree were determined. Data were analyzed statistically by Excel 2003 and SPSS 13.0 software. [ Result] There was a significant difference （P 〈 0.05） between the grassland caterpillars at different hazard grades and the structure of alpine Kobresia meadow or soil properties. [ Conclusion] With the increase of grassland caterpillar density, the plant community structure of alpine Kobresia meadows changes from sedge family-dominant community to the forbs-dominant community.
基金Supported by Daqing"Jiebangguashuai"Science and Technology Key Project in the New Energy Field (2021BD05)。
文摘[Objectives] This study was conducted to explore the characteristics of natural grassland plant communities in the National Photovoltaic and Energy Storage Empirical Experiment Platform(Daqing Base), so as to provide data reference for local grassland resources. [Methods] June to July, 2022, standard plot site investigation was carried out to investigate vegetation species, relative height, relative coverage, relative abundance, relative frequency and dominance in the National Photovoltaic and Energy Storage Empirical Experiment Platform in Datong District, Daqing City of Heilongjiang Province, and to analyze plant community structures in the photovoltaic DC field. [Results] The photovoltaic DC field contained 22 species of plants, of which Suaeda salsa was the common species. The dominant species in photovoltaic DC field were Leymus chinensis, Eleocharis intersita, Carex duriuscula and Carex rugurosa. [Conclusions] The dominant vegetation types were Poaceae and Cyperaceae in the natural grassland of the National Photovoltaic and Energy Storage Empirical Experiment Platform(Daqing Base).
基金Sponsored by the National Natural Science Foundation of China(41661064)。
文摘A sand-accumulation belt came into being during the process of desert control in recent 60 years at the edge of oasis,especially at the upwind places in desert area in Hexi Corridor of Gansu.Among them,the sand-accumulation belt at the edge of Minqin Oasis is relatively typical and the most complete.The vegetation on the sand-accumulation belt is not only the formation factor of the sand-accumulation belt,but also an important factor to maintain the stability of the sand-accumulation belt.In a certain sense,the health status of the vegetation of the sand-accumulation belt determines the stability of the sand-accumulation belt.In order to analyze the vegetation status of the sand-accumulation belt,the health sequence analysis of the plant community was carried out of sand-accumulation belt at the edge of Minqin Oasis,by setting 11 lines of equal spacing of sand-accumulation belt at the edge of Minqin Oasis,and through the vegetation survey of more than 60 samples.The vegetation on the sand-accumulation belt at the edge of Minqin Oasis is generally unhealthy.But for the health sequence of this study,the health status of vegetation of the sand-accumulation belt formed by artificial sand fixation forest is better than that of vegetation of the sand-accumulation belt formed by natural shrub at the edge of Minqin Oasis.The health status of vegetation of the sand-accumulation belt of mixed forest of arbor and shrub is the worst at the edge of Minqin Oasis.The dominant species Tamarix laxa on the sand-accumulation belt in the lower reaches of the oasis are seriously withered,and their health is the worst.There is potential danger of the sand-accumulation belt being blown and activated.After abandonment of farmland,protection of protection forest and sand-accumulation belt at the edge of farmland in sand area is a new problem,which is worth considering.
基金Supported by Entrusted Project of Shenzhen Environmental Monitoring Center Station(D11520349)Science and Technology Project of Construction and Works Bureau in Shenzhen Dapeng New Area(QT 2016-166).
文摘The overexploitation of the natural environment caused by urbanization makes more and more natural and semi-natural plant communities gradually lack,which causes a lot of irreversible damage to the environment.Therefore,it is very important to carry out ecological environment construction in all fields of urban construction.In this paper,based on theory and method of plant landscape construction under the concept of"nearly natural"plant community,through the investigation and analysis on plant species,distribution,and structural characteristics of plant community in Baguang District of Shenzhen,regional native plant species are summarized,and structural characteristics of original zonal plant community are simulated.The research aims to provide a reference basis for creating a coastal plant landscape with subtropical marine climate for Baguang and even Lingnan,constructing near natural ecological park according to local conditions,forming the pattern well-coordinated with the local natural ecosystem,and carrying out protection of the regional ecological environment.
基金Under the auspices of Ministry of Education, China (No. 108148)State Key Laboratory of Urban and Regional Ecology (No. SKLURE2010-2-2)+1 种基金National Basic Research Program of China (No. 2010CB951203)Key Research Program of Shanghai Science & Technology (No. 08231200700, 08231200702)
文摘To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in April 2009, and TM (30 m) data in 2006, the composition and characteristics of natural plants community in different time of the Fengxian area in the Changjiang (Yangtze) River estuary were analyzed with two-way indicator species analysis (TWINSPAN), multivariate analysis of variance (MANOVA), detrended canonical correspondence analysis (DCCA) and canonical correspondence analysis (CCA). The results show that: 1) The plant communities in the reclaimed area are mainly mesophytes and helophytic-mesophytic transitional communities, showing a gradient distribution trend with the change in reclamation years. Species richness (MA), species diversity (H) and above-ground biomass also increase with the increase of reclamation years. Nevertheless, they appear to decline slightly in the middle and late reclamation period (> 30 years). 2) With the rise in land use levels, the changes in species richness and species diversity tend to increase at first and then decrease; species dominance (D), however, tends to decline; and above-ground biomass increases slightly. 3) The distribution of the plant community is mainly influenced by the following factors: land use levels (R = 0.55, p < 0.05), soil moisture (R = 0.53, p < 0.05), soil salinity (R = 0.43, p < 0.05) and reclamation time (R = 0.40, p < 0.05).
基金Funds of China West Normal University (17YC332 17YC114)+2 种基金the National Natural Science Foundation of China (31572293)the Natural Science project of the Sichuan Department of Education (16ZB0177)the Fundamental Research Funds of China West Normal University (14D010)
文摘The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events,vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter's variance ratio, pearson's chi-squared test, Spearman's correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups.This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing,and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area.
基金funded by the National Natural Science Foundation of China(32471953)the Educational Department of Liaoning Province Key Research Project(LJ212410153073).
文摘Urban green spaces have positive effects on both physical and mental wellbeing.However,few studies have focused on the trends and thresholds of the effects of different influences on restorative benefits when viewing scenes differfeaturing plant communities.We measured subjective evaluations and objective physiological data from 44 participants who viewed images of plant communities in the yellow to green hue range to compare differences in restorative benefits among plant communities at different visual distances,as well as quantifying the influencing factors involved.The following results were found:(1)Coniferous and multi-layered plant communities were found to provide greater restorative benefits,and the restorative benefits grew with increasing visual distance.(2)Shape and color characteristics were significantly correlated with restorative benefits,but the relationship is not simply linear.(3)The restorative benefits were found to be greatest when crown proportion was 61.23%,trunk proportion ranged from 4.11%to 13.70%,and the value of color index value ranged from 25.44%to 35.56%;the restorative benefits gradually increased when sky proportion exceeded 12.95%-13.19%,the fractal dimension exceeded 1.62-1.67,and hue index exceeded 91.64°-95.67°;additionally,the restorative benefits decreased when the saturation index increased.This study provides a scientific basis for the construction and improvement of plant landscapes in urban green spaces.
基金supported by the National Key Research and Development Program of China(2025YFE0103800,2023YFE0102600,2024YFE0214200).
文摘Livestock farming is a critical pillar of Tajikistan’s national economy and livelihood security.However,significant economic challenges in the country have led to the degradation of grassland ecosystems.This degradation has not only reduced the productivity of grassland ecosystems but also severely impacted their ecological functions.A particularly concerning consequence is the threat to biodiversity,as the survival and persistence of endemic,rare,and endangered plant species are at serious risk,thereby diminishing the value of species’genetic resources.Based on the data from multiple sources such as literature reviews,field observations,and national statistics,this study employed a systematic literature review and meta-analysis to investigate the current status,causes of degradation,and restoration measures for grassland ecosystems in Tajikistan.The results revealed that Tajikistan’s grassland ecosystems support exceptionally high plant species diversity,comprising over 4500 vascular plant species,including nearly 1500 endemic and sub-endemic taxa that constitute a unique genetic reservoir.These ecosystems are experiencing severe degradation,characterized by significantly reduced vegetation cover and declining species richness.Palatable forage species are increasingly being displaced by unpalatable,thorny,and poisonous species.The primary drivers of degradation include excessive grazing pressure,which disrupts plant reproductive cycles and regeneration capacity,habitat fragmentation due to urbanization and infrastructure development,and uncontrolled exploitation of medicinal and edible plants.Climate change,particularly rising temperatures and altered precipitation patterns,further exacerbates these anthropogenic pressures.Ecological restoration experiments suggested that both ecosystem productivity and plant species diversity are significantly enhanced by systematic reseeding trials using altitude-adapted native species.These findings underscore the necessity of establishing scientifically grounded approaches for ecological restoration.
基金supported by the United States Department of Agriculture,Forest Service,Rocky Mountain Research Station through Research Joint Venture Agreement 17–098Funding was provided by the USDA Forest Service Northern Region。
文摘Understory plants are an integral part of forests,serving a variety of functions that help maintain healthy ecosystems.The structure and composition of the understory are influenced by numerous biotic and abiotic factors,with light being critical.The introduction of the pathogen Cronartium ribicola,which causes white pine blister rust,into North America in the early 20 th century led to the near total loss of western white pine(Pinus monticola)from moist forests of the Northern Rockies.Management is reintroducing blister rust-resistant western white pine across the landscape,but the effects on the understory are unknown.We examined the effects of stand structure and proportion of western white pine in the overstory on understory diversity of vascular plants in closed canopy stands dominated by blister rust-resistant western white pine across northern Idaho.Habitat series explained the greatest amount of variation(34%)in species presence-absence,while canopy cover accounted for 25%,basal area of all trees for 18%,and the proportion of western white pine composition by 14%.Our analysis revealed positive relationships between the proportion of western white pine in the overstory and both the presence of understory plants and the cover of several understory species.For both the presence and cover,separate sets of thirteen species were found to have a positive relationship with the proportion of western white pine in the overstory,with eight species in common.This research fills a knowledge gap by using data from a range of stands across northern Idaho with varying abundance of western white pine in the overstory to evaluate the relationship between the understory and overstory composition.As land managers plant more western white pine trees,we are likely to see the concomitant increase in understory plant diversity across the landscape,in addition to numerous other benefits,including disturbance resistance and resilience.
基金Supported by the National Natural Science Foundation of China （90102015, 30170161） and Cooperation Project of International in China and Greece （2003DFB0034）
文摘For more than a century, ecologists have concentrated on competition as a crucial process for community organization. However, more recent experimental investigations have uncovered the striking Influence of positive Interactions on the organization of plant communities. Complex combinations of competition and positive interactions operating simultaneously among plant species seem to be widespread In nature. In the present paper, we reviewed the mechanism and ecological importance of positive Interactions In plant communities, emphasizing the certainties and uncertainties that have made It an attractive area of research. Positive Interactions, or facilitation, occur when one species enhances the survival, growth, or richness of another. The Importance of facilitation in plant organization increases with ablotlc stress and the relative Importance of competition decreases. Only by combining plant interactions and the many fields of biology can we fully understand how and when the positive Interactions occur.
基金the National Science Foundation of China(41871040)the Second Tibetan Plateau Scientific Expedition and Research(2019QZKK0405)Joint Research Project of Three-River-Resource National Park funded by the Chinese Academy of Sciences and Qinghai Provincial People's Government(LHZX-2020-08).
文摘A better understanding the mechanisms driving plant biomass allocation in different ecosystems is an important theoretical basis for ilustrating the adaptive strategies of plants.To date,the effects of habitat conditions on plant biomass allocation have been widely studied.However,it is less known how plant community traits and functions(PCTF)affect biomass allocation,particularly in alpine grassland ecosystems.In this study,community-weighted means(CWM)were calculated at the community level using five leaf functional traits,and the relationships between PCTF and biomass trade-offs were explored using correlation analysis,variation partitioning analysis and structural equation modeling.We found that the trade-off values were greater than zero in both alpine meadow(AM)and alpine steppe(AS)across the Tibetan Plateau,with different values of 0.203 and 0.088 for AM and AS,respectively.Moreover,the critical factors determining biomass allocation in AS were species richness(SR;scored at 0.69)and leaf dry matter content of CWM(CWM_(LDMC),scored at 0.42),while in AM,the key factors were leaf dry matter content(CWM.pMC scored at 0.48)and leaf carbon content of CWM(CWM_(LC),scored at-0.45).In particular,both CWM_(LDMC)and SR in AS,as well as CWM_(LDMC)and CWM_(LDMC)in AM were primarily regulated by precipitation.In summary,precipitation tends to drive biomass allocation in alpine grasslands through its effects on PCTF,hence highlighting the importance of PCTF in regulating plant biomass allocation strategies along precipitation gradients.
