Tree mortality significantly influences forest structure and function,yet our understanding of its dynamic patterns among a range of tree sizes and among different plant functional types(PFTs)remains incomplete.This s...Tree mortality significantly influences forest structure and function,yet our understanding of its dynamic patterns among a range of tree sizes and among different plant functional types(PFTs)remains incomplete.This study analysed size-dependent tree mortality in a temperate forest,encompassing 46 tree species and 32,565 individuals across different PFTs(i.e.,evergreen conifer vs.deciduous broadleaf species,shade-tolerant vs.shade-intolerant species).By employing all-subset regression procedures and logistic generalized linear mixed-effects models,we identified distinct mortality patterns influenced by biotic and abiotic factors.Our results showed a stable mortality patte rn in eve rgreen conifer species,contrasted by a declining pattern in deciduous broadleaf and shadetolerant,as well as shade-intolerant species,across size classes.The contribution to tree mortality of evergreen conifer species shifted from abiotic to biotic factors with increasing size,while the mortality of deciduous broadleaf species was mainly influenced by biotic factors,such as initial diameter at breast height(DBH)and conspecific negative density.For shade-tolerant species,the mortality of small individuals was mainly determined by initial DBH and conspecific negative density dependence,whereas the mortality of large individuals was subjected to the combined effect of biotic(competition from neighbours)and abiotic factors(i.e.,convexity and pH).As for shade-intolerant species,competition from neighbours was found to be the main driver of tree mortality throughout their growth stages.Thus,these insights enhance our understanding of forest dynamics by revealing the size-dependent and PFT-specific tree mortality patterns,which may inform strategies for maintaining forest diversity and resilience in temperate forest ecosystems.展开更多
The ecological concept of Plant Functional Types（PFTs）, which refers to the assemblage of plants with certain functional traits, has been introduced for the study of plant responses to the environment change and hum...The ecological concept of Plant Functional Types（PFTs）, which refers to the assemblage of plants with certain functional traits, has been introduced for the study of plant responses to the environment change and human disturbance. Taking the alpine meadow community in the Zoigê Plateau as a study case, this paper classified PFTs in terms of plant nutrition traits. The sequential results are as follows.（1） The main herbages in the Zoigê Plateau included 16 species in 5 families. Among the five families, Cyperaceae vegetation accounted for 81.37%of herbage area in total, while the remaining 4families occupied less than 20%. As for the species,Kobresia setchwanensis Hand.-Maizz. was dominant,accounting for 48.74% of the total area; while the remaining 51.26% was comprised of Polygonum viviparum L., Anaphalis fiavescens Hand.-Mazz.,Stipa aliena Keng and other species.（2） By using the Principal Component Analysis（PCA）, the assessment of herbages nutrition was carried out based on the comprehensive multi-index evaluation model.Polygonum viviparum L. had the highest nutritional value score（1.43）, and Stipa aliena Keng had the lowest（-1.40）. Nutritional value of herbage species had a significantly positive correlation with altitude（P＆lt;0.01） in the Zoigê Plateau.（3） Based on the nutritional values, herbages in the Zoigê Plateau could be grouped into 3 nutrition PFTs（high, medium and low） by using the Natural Breaks（Jenks） method.展开更多
Land surface models and dynamic global vegetation models typically represent vegetation through coarse plant functional type groupings based on leaf form, phenology, and bioclimatic limits. Although these groupings we...Land surface models and dynamic global vegetation models typically represent vegetation through coarse plant functional type groupings based on leaf form, phenology, and bioclimatic limits. Although these groupings were both feasible and functional for early model generations, in light of the pace at which our knowledge of functional ecology, ecosystem demographics, and vegetation-climate feedbacks has advanced and the ever growing demand for enhanced model performance, these groupings have become antiquated and are identified as a key source of model uncertainty. The newest wave of model development is centered on shifting the vegetation paradigm away from plant functional types(PFTs)and towards flexible trait-based representations. These models seek to improve errors in ecosystem fluxes that result from information loss due to over-aggregation of dissimilar species into the same functional class. We advocate the importance of the inclusion of plant hydraulic trait representation within the new paradigm through a framework of the whole-plant hydraulic strategy. Plant hydraulic strategy is known to play a critical role in the regulation of stomatal conductance and thus transpiration and latent heat flux. It is typical that coexisting plants employ opposing hydraulic strategies, and therefore have disparate patterns of water acquisition and use. Hydraulic traits are deterministic of drought resilience, response to disturbance, and other demographic processes. The addition of plant hydraulic properties in models may not only improve the simulation of carbon and water fluxes but also vegetation population distributions.展开更多
We conducted a systematic census of leaf N for 102 plant species at 112 research sites along the North-South Transect of Eastern China （NSTEC） following the same protocol, to explore how plant functional types （PFT...We conducted a systematic census of leaf N for 102 plant species at 112 research sites along the North-South Transect of Eastern China （NSTEC） following the same protocol, to explore how plant functional types （PFTs） and environmental factors affect the spatial pattern of leaf N. The results showed that mean leaf N was 17.7 mg g^-1 for all plant species. The highest and lowest leaf N were found in deciduous-broadleaf and evergreen-conifer species, respectively, and the ranking of leaf N from high to low was： deciduous 〉 evergreen species, broadleaf 〉 coniferous species, shrubs ≈ trees 〉 grasses. For all data pooled, leaf N showed a convex quadratic response to mean annual temperature （MAT）, and a negative linear relationship with mean annual precipitation （MAP）, but a positive linear relationship with soil nitrogen concentration （Nsoil）. These patterns were similar when PFTs were examined individually. Importantly, PFTs, climate and Nsoil, jointly explained 46.1% of the spatial variation in leaf N, of which the independent explanatory powers of PFTs, climate and Nsoil, were 15.6%, 2.3% and 4.7%, respectively. Our findings suggest that leaf N is regulated by climate and Nsoil, mainly via plant species composition. The wide scale empirical relationships developed here are useful for understanding and modeling of the effects of PFTs and environmental factors on leaf N.展开更多
Land use projections are crucial for climate models to forecast the impacts of land use changes on the Earth’s system.However,the spatial resolution of existing global land use projections(e.g.,0.25°×0.25&#...Land use projections are crucial for climate models to forecast the impacts of land use changes on the Earth’s system.However,the spatial resolution of existing global land use projections(e.g.,0.25°×0.25°in the Land-Use Harmonization(LUH2)datasets)is still too coarse to drive regional climate models and assess mitigation effectiveness at regional and local scales.To generate a high-resolution land use product with the newest integrated scenarios of the shared socioeconomic pathways and the representative concentration pathways(SSPs-RCPs)for various regional climate studies in China,here we first conduct land use simulations with a newly developed Future Land Uses Simulation(FLUS)model based on the trajectories of land use demands extracted from the LUH2 datasets.On this basis,a new set of land use projections under the plant functional type(PFT)classification,with a temporal resolution of 5 years and a spatial resolution of 5 km,in eight SSP-RCP scenarios from 2015 to 2100 in China is produced.The results show that differences in land use dynamics under different SSP-RCP scenarios are jointly affected by global assumptions and national policies.Furthermore,with improved spatial resolution,the data produced in this study can sufficiently describe the details of land use distribution and better capture the spatial heterogeneity of different land use types at the regional scale.We highlight that these new land use projections at the PFT level have a strong potential for reducing uncertainty in the simulation of regional climate models with finer spatial resolutions.展开更多
The identification of easily measured plant functional types (PFTs) that consistently predict grazing response would be a major advance.The responses to grazing of individual traits and PFTs were analyzed along a graz...The identification of easily measured plant functional types (PFTs) that consistently predict grazing response would be a major advance.The responses to grazing of individual traits and PFTs were analyzed along a grazing gradient in an alpine shrub meadow on the Qinghai-Tibet Plateau,China.Three response types were identified;grazing increaser (GI),grazing decreaser (GD),and neutral (NE) for both traits and PFTs.Seven traits were measured:plant height,economic group,cotyledon type,plant inclination,growth form,life cycle,and vegetative structure.The first five were significantly affected by grazing.Ordinal regressions for grazing response of the seven traits showed that the best single predictors of response were growth form (including the attributes "Scattered","Bunched" or "Closely Bunched"),and plant inclination ("Rosette","Prostrate",or "Erect"),followed by economic group ("Shrub","Grass","Sedge","Legume","Forb",or "Harmful") and plant height ("Tall","Medium",or "Small").Within the four optimal traits,the summed dominance ratio (SDR) of small plants,forbs,rosette and bunched plants,invariably increased,while that of tall plants,shrubs,grasses,and erect plants decreased,when grazing pressure was enhanced.Canonical correspondence analysis (CCA) identified eleven explanatory PFTs based on 195 defined PFTs,by combining the different attributes of the four optimal traits.Among explanatory PFTs,the most valuable in predicting the community response to grazing were Tall×Shrub×Erect×Scattered and Small×Forb×Rosette,as these have the closest connections with grazing disturbance and include fewer species.Species richness,diversity,and community evenness,did not differ among grazing treatments because turnover occurred in component species and their relative abundances along the grazing gradient.We have demonstrated that a minimum set of PFTs resulting from optimal individual traits can provide consistent prediction of community responses to grazing in this region.This approach provides a more accurate indicator of change within a changing environment than do univariate measures of species diversity.We hope to provide a link between management practices and vegetation structure,forming a basis for future,large scale,plant trait comparisons.展开更多
为揭示系统发育和植物功能性状对新疆木本植物开花物候的影响,以新疆乌鲁木齐、伊宁和喀什三地典型植物园或公园的木本植物为研究对象,利用系统发育信号值和系统发育广义最小二乘模型(Phylogenetic Generalized Least Squares, PGLS),...为揭示系统发育和植物功能性状对新疆木本植物开花物候的影响,以新疆乌鲁木齐、伊宁和喀什三地典型植物园或公园的木本植物为研究对象,利用系统发育信号值和系统发育广义最小二乘模型(Phylogenetic Generalized Least Squares, PGLS),探究开花物候分布特征、谱系保守性以及功能性状的贡献率。结果表明:(1)新疆木本植物开花期集中在3月31日至4月20日,持续时间为(13.03±0.38)d。乔木、肉质果、彩色花和风媒植物分别比灌木、非肉质果、非彩色花和虫媒植物的开花早。(2)亲缘关系越近的物种开花物候特征越相似,系统发育信号值Pagel’sλ为0.67~0.74。(3)果实类型、花色和传粉方式与开花物候最相关,解释度为17.4%~31.6%。本研究证明系统发育和植物功能性状均能影响新疆木本植物开花物候,研究结果对阐明干旱区生物多样性维持机制和虫植关系具有重要意义。展开更多
Potassium(K),calcium(Ca),and magnesium(Mg)are essential elements with important physiological functions in plants.Previous studies showed that leaf K,Ca,and Mg concentrations generally increase with increasing latitud...Potassium(K),calcium(Ca),and magnesium(Mg)are essential elements with important physiological functions in plants.Previous studies showed that leaf K,Ca,and Mg concentrations generally increase with increasing latitudes.However,recent meta-analyses suggested the possibility of a unimodal pattern in the concentrations of these elements along latitudinal gradients.The authenticity of this unimodal latitudinal pattern,however,requires validation through large-scale field experimental data,and exploration of the underlying mechanisms if the pattern is confirmed.Here,we collected leaves of common species of woody plants from 19 montane forests in the north-south transect of eastern China,including 322 species from 160 genera,67 families;and then determined leaf K,Ca,and Mg concentrations to explore their latitudinal patterns and driving mechanisms.Our results support unimodal latitudinal patterns for all three elements in woody plants across eastern China,with peak values at latitude 36.5±1.0°N.The shift of plant-functional-type compositions from evergreen broadleaves to deciduous broadleaves and to conifers along this latitudinal span was the key factor contributing to these patterns.Climatic factors,mainly temperature,and to a lesser extent solar radiation and precipitation,were the main environmental drivers.These factors,by altering the composition of plant communities and regulating plant physiological activities,influence the latitudinal patterns of plant nutrient concentrations.Our findings also suggest that high leaf K,Ca,and Mg concentrations may represent an adaptive strategy for plants to withstand water stress,which might be used to predict plant nutrient responses to climate changes at large scales,and broaden the understanding of biogeochemical cycling of K,Ca,and Mg.展开更多
Wood density(WD)is an important quality and functional trait of wood.However,despite the relationships between WD and abiotic factors being important to model or predict spatial distributions of functional traits,as w...Wood density(WD)is an important quality and functional trait of wood.However,despite the relationships between WD and abiotic factors being important to model or predict spatial distributions of functional traits,as well as responses of vegetation to climate changes,in current Earth system models or dynamic global vegetation models(ESMs/DGVMs),WD is often oversimplified,being defined as a globally uniform constant either for all plant functional types(PFTs)or for each individual PFT.Such oversimplifications may lead to simulation biases in the morphology of woody PFTs,as well as ecosystem transition and vegetation-atmosphere interactions.Moreover,existing conclusions about the relationships between WD and abiotic factors drawn from field observations remain mixed,making model parameterization improvements difficult.This study systematically investigated the influences of climate and soil factors on WD across various PFTs.Optimal fitting models for predicting WD within each PFT were then constructed by utilizing our collated global database of 138604 observations.For WDs of tree PFTs,climate emerges as a more influential factor than soil characteristics,whereas for shrub PFTs the effects of climate and soil are of equivalent significance.Across all six PFTs,correlation coefficients between predictions by fitting models and observed WD range from 0.49 to 0.93.The predicted and observed WD exhibit good agreement across climate space.It is expected that the incorporation of our research findings into DGVMs will improve the simulation of tree height and forest fractional coverage,particularly in the central forest areas and forest transition zones.展开更多
基金supported by the China Postdoctoral Science Foundation (No.2023M733712)the National Natural Science Foundation of China (No.31971491)。
文摘Tree mortality significantly influences forest structure and function,yet our understanding of its dynamic patterns among a range of tree sizes and among different plant functional types(PFTs)remains incomplete.This study analysed size-dependent tree mortality in a temperate forest,encompassing 46 tree species and 32,565 individuals across different PFTs(i.e.,evergreen conifer vs.deciduous broadleaf species,shade-tolerant vs.shade-intolerant species).By employing all-subset regression procedures and logistic generalized linear mixed-effects models,we identified distinct mortality patterns influenced by biotic and abiotic factors.Our results showed a stable mortality patte rn in eve rgreen conifer species,contrasted by a declining pattern in deciduous broadleaf and shadetolerant,as well as shade-intolerant species,across size classes.The contribution to tree mortality of evergreen conifer species shifted from abiotic to biotic factors with increasing size,while the mortality of deciduous broadleaf species was mainly influenced by biotic factors,such as initial diameter at breast height(DBH)and conspecific negative density.For shade-tolerant species,the mortality of small individuals was mainly determined by initial DBH and conspecific negative density dependence,whereas the mortality of large individuals was subjected to the combined effect of biotic(competition from neighbours)and abiotic factors(i.e.,convexity and pH).As for shade-intolerant species,competition from neighbours was found to be the main driver of tree mortality throughout their growth stages.Thus,these insights enhance our understanding of forest dynamics by revealing the size-dependent and PFT-specific tree mortality patterns,which may inform strategies for maintaining forest diversity and resilience in temperate forest ecosystems.
基金supported by the sub topics of National Key Technology R&D Program (Grant No. 2015BAC05B05-01)
文摘The ecological concept of Plant Functional Types（PFTs）, which refers to the assemblage of plants with certain functional traits, has been introduced for the study of plant responses to the environment change and human disturbance. Taking the alpine meadow community in the Zoigê Plateau as a study case, this paper classified PFTs in terms of plant nutrition traits. The sequential results are as follows.（1） The main herbages in the Zoigê Plateau included 16 species in 5 families. Among the five families, Cyperaceae vegetation accounted for 81.37%of herbage area in total, while the remaining 4families occupied less than 20%. As for the species,Kobresia setchwanensis Hand.-Maizz. was dominant,accounting for 48.74% of the total area; while the remaining 51.26% was comprised of Polygonum viviparum L., Anaphalis fiavescens Hand.-Mazz.,Stipa aliena Keng and other species.（2） By using the Principal Component Analysis（PCA）, the assessment of herbages nutrition was carried out based on the comprehensive multi-index evaluation model.Polygonum viviparum L. had the highest nutritional value score（1.43）, and Stipa aliena Keng had the lowest（-1.40）. Nutritional value of herbage species had a significantly positive correlation with altitude（P＆lt;0.01） in the Zoigê Plateau.（3） Based on the nutritional values, herbages in the Zoigê Plateau could be grouped into 3 nutrition PFTs（high, medium and low） by using the Natural Breaks（Jenks） method.
基金Funding for this study was provided by the U.S. National Science Foundation Hydrological Science grant 1521238the U.S. Department of Energy's Office of Science Office of Biological and Environmental Research,Terrestrial Ecosystem Sciences Program Award No. DE-SC0007041Ameriflux Management Project Core Site Agreement No. 7096915
文摘Land surface models and dynamic global vegetation models typically represent vegetation through coarse plant functional type groupings based on leaf form, phenology, and bioclimatic limits. Although these groupings were both feasible and functional for early model generations, in light of the pace at which our knowledge of functional ecology, ecosystem demographics, and vegetation-climate feedbacks has advanced and the ever growing demand for enhanced model performance, these groupings have become antiquated and are identified as a key source of model uncertainty. The newest wave of model development is centered on shifting the vegetation paradigm away from plant functional types(PFTs)and towards flexible trait-based representations. These models seek to improve errors in ecosystem fluxes that result from information loss due to over-aggregation of dissimilar species into the same functional class. We advocate the importance of the inclusion of plant hydraulic trait representation within the new paradigm through a framework of the whole-plant hydraulic strategy. Plant hydraulic strategy is known to play a critical role in the regulation of stomatal conductance and thus transpiration and latent heat flux. It is typical that coexisting plants employ opposing hydraulic strategies, and therefore have disparate patterns of water acquisition and use. Hydraulic traits are deterministic of drought resilience, response to disturbance, and other demographic processes. The addition of plant hydraulic properties in models may not only improve the simulation of carbon and water fluxes but also vegetation population distributions.
基金supported by the National Key Research and Development Program (2010CB833504)the CAS Strategic Priority Research Program (XDA05050602)
文摘We conducted a systematic census of leaf N for 102 plant species at 112 research sites along the North-South Transect of Eastern China （NSTEC） following the same protocol, to explore how plant functional types （PFTs） and environmental factors affect the spatial pattern of leaf N. The results showed that mean leaf N was 17.7 mg g^-1 for all plant species. The highest and lowest leaf N were found in deciduous-broadleaf and evergreen-conifer species, respectively, and the ranking of leaf N from high to low was： deciduous 〉 evergreen species, broadleaf 〉 coniferous species, shrubs ≈ trees 〉 grasses. For all data pooled, leaf N showed a convex quadratic response to mean annual temperature （MAT）, and a negative linear relationship with mean annual precipitation （MAP）, but a positive linear relationship with soil nitrogen concentration （Nsoil）. These patterns were similar when PFTs were examined individually. Importantly, PFTs, climate and Nsoil, jointly explained 46.1% of the spatial variation in leaf N, of which the independent explanatory powers of PFTs, climate and Nsoil, were 15.6%, 2.3% and 4.7%, respectively. Our findings suggest that leaf N is regulated by climate and Nsoil, mainly via plant species composition. The wide scale empirical relationships developed here are useful for understanding and modeling of the effects of PFTs and environmental factors on leaf N.
文摘为了探究海拔对我国西南高寒地区植物稳定碳同位素组成特征及水分利用效率的影响,本研究以梅里雪山东坡不同海拔(2200、2500、2700、3000、3200和4200 m)上不同功能型植物为对象,分析了不同光合途径(C3和Crassulacean acid metabolism,CAM)植物和C3植物中不同生活型(灌木、阔叶乔木和针叶乔木)植物叶片稳定碳同位素组成特征(δ^(13)C_(p))及内在水分利用效率(intrinsic water use efficiency,iWUE)随海拔梯度的变化。结果表明:(1)梅里雪山东坡C3植物叶片的δ^(13)C_(p)值分布范围在-26.72‰~-31.67‰,均值为-29.12‰,而CAM植物的δ^(13)C_(p)值分布范围在-13.24‰~-14.59‰,均值为-13.77‰;(2)CAM植物δ^(13)C_(p)值和iWUE显著高于C3植物,其中,C3植物中不同生活型植物δ^(13)C_(p)和iWUE值呈现灌木>阔叶乔木>针叶乔木的变化规律;(3)海拔3200 m以下乔木和灌木植物δ^(13)C_(p)和iWUE值随海拔升高而降低,主要受土壤水分的影响,3200 m以上灌木植物δ^(13)C_(p)和iWUE值随海拔升高有增大的趋势,可能受温度的调控。梅里雪山东坡不同功能型植物水分利用效率对海拔梯度的响应反映了不同植物对高寒山地气候不同的适应性。
基金the National Key Research&Development Program of China(2019YFA0607203,2017YFA0604404)the National Natural Science Foundation of China(41901327,41671398,41871318)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(2019A1515010823)the Fundamental Research Funds for the Central Universities(19lgpy41)Natural Resources of the People’s Republic of China(GS(2020)2879)。
文摘Land use projections are crucial for climate models to forecast the impacts of land use changes on the Earth’s system.However,the spatial resolution of existing global land use projections(e.g.,0.25°×0.25°in the Land-Use Harmonization(LUH2)datasets)is still too coarse to drive regional climate models and assess mitigation effectiveness at regional and local scales.To generate a high-resolution land use product with the newest integrated scenarios of the shared socioeconomic pathways and the representative concentration pathways(SSPs-RCPs)for various regional climate studies in China,here we first conduct land use simulations with a newly developed Future Land Uses Simulation(FLUS)model based on the trajectories of land use demands extracted from the LUH2 datasets.On this basis,a new set of land use projections under the plant functional type(PFT)classification,with a temporal resolution of 5 years and a spatial resolution of 5 km,in eight SSP-RCP scenarios from 2015 to 2100 in China is produced.The results show that differences in land use dynamics under different SSP-RCP scenarios are jointly affected by global assumptions and national policies.Furthermore,with improved spatial resolution,the data produced in this study can sufficiently describe the details of land use distribution and better capture the spatial heterogeneity of different land use types at the regional scale.We highlight that these new land use projections at the PFT level have a strong potential for reducing uncertainty in the simulation of regional climate models with finer spatial resolutions.
基金supported by National Natural Science Foundation of China (Grant Nos. 30671490, and 31070382)
文摘The identification of easily measured plant functional types (PFTs) that consistently predict grazing response would be a major advance.The responses to grazing of individual traits and PFTs were analyzed along a grazing gradient in an alpine shrub meadow on the Qinghai-Tibet Plateau,China.Three response types were identified;grazing increaser (GI),grazing decreaser (GD),and neutral (NE) for both traits and PFTs.Seven traits were measured:plant height,economic group,cotyledon type,plant inclination,growth form,life cycle,and vegetative structure.The first five were significantly affected by grazing.Ordinal regressions for grazing response of the seven traits showed that the best single predictors of response were growth form (including the attributes "Scattered","Bunched" or "Closely Bunched"),and plant inclination ("Rosette","Prostrate",or "Erect"),followed by economic group ("Shrub","Grass","Sedge","Legume","Forb",or "Harmful") and plant height ("Tall","Medium",or "Small").Within the four optimal traits,the summed dominance ratio (SDR) of small plants,forbs,rosette and bunched plants,invariably increased,while that of tall plants,shrubs,grasses,and erect plants decreased,when grazing pressure was enhanced.Canonical correspondence analysis (CCA) identified eleven explanatory PFTs based on 195 defined PFTs,by combining the different attributes of the four optimal traits.Among explanatory PFTs,the most valuable in predicting the community response to grazing were Tall×Shrub×Erect×Scattered and Small×Forb×Rosette,as these have the closest connections with grazing disturbance and include fewer species.Species richness,diversity,and community evenness,did not differ among grazing treatments because turnover occurred in component species and their relative abundances along the grazing gradient.We have demonstrated that a minimum set of PFTs resulting from optimal individual traits can provide consistent prediction of community responses to grazing in this region.This approach provides a more accurate indicator of change within a changing environment than do univariate measures of species diversity.We hope to provide a link between management practices and vegetation structure,forming a basis for future,large scale,plant trait comparisons.
文摘为揭示系统发育和植物功能性状对新疆木本植物开花物候的影响,以新疆乌鲁木齐、伊宁和喀什三地典型植物园或公园的木本植物为研究对象,利用系统发育信号值和系统发育广义最小二乘模型(Phylogenetic Generalized Least Squares, PGLS),探究开花物候分布特征、谱系保守性以及功能性状的贡献率。结果表明:(1)新疆木本植物开花期集中在3月31日至4月20日,持续时间为(13.03±0.38)d。乔木、肉质果、彩色花和风媒植物分别比灌木、非肉质果、非彩色花和虫媒植物的开花早。(2)亲缘关系越近的物种开花物候特征越相似,系统发育信号值Pagel’sλ为0.67~0.74。(3)果实类型、花色和传粉方式与开花物候最相关,解释度为17.4%~31.6%。本研究证明系统发育和植物功能性状均能影响新疆木本植物开花物候,研究结果对阐明干旱区生物多样性维持机制和虫植关系具有重要意义。
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA26040202)the National Natural Science Foundation of China(41173083)+1 种基金SL was also supported by the National Natural Science Foundation of China(32001165)the Natural Science Foundation of Sichuan Province(2022NSFSC1753)。
文摘Potassium(K),calcium(Ca),and magnesium(Mg)are essential elements with important physiological functions in plants.Previous studies showed that leaf K,Ca,and Mg concentrations generally increase with increasing latitudes.However,recent meta-analyses suggested the possibility of a unimodal pattern in the concentrations of these elements along latitudinal gradients.The authenticity of this unimodal latitudinal pattern,however,requires validation through large-scale field experimental data,and exploration of the underlying mechanisms if the pattern is confirmed.Here,we collected leaves of common species of woody plants from 19 montane forests in the north-south transect of eastern China,including 322 species from 160 genera,67 families;and then determined leaf K,Ca,and Mg concentrations to explore their latitudinal patterns and driving mechanisms.Our results support unimodal latitudinal patterns for all three elements in woody plants across eastern China,with peak values at latitude 36.5±1.0°N.The shift of plant-functional-type compositions from evergreen broadleaves to deciduous broadleaves and to conifers along this latitudinal span was the key factor contributing to these patterns.Climatic factors,mainly temperature,and to a lesser extent solar radiation and precipitation,were the main environmental drivers.These factors,by altering the composition of plant communities and regulating plant physiological activities,influence the latitudinal patterns of plant nutrient concentrations.Our findings also suggest that high leaf K,Ca,and Mg concentrations may represent an adaptive strategy for plants to withstand water stress,which might be used to predict plant nutrient responses to climate changes at large scales,and broaden the understanding of biogeochemical cycling of K,Ca,and Mg.
基金supported by the National Natural Science Foundation of China(Grant No.42275177)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2021B0301030007)the National Key Scientific and Technological Infrastructure project“Earth System Numerical Simulation Facility”(EarthLab).
文摘Wood density(WD)is an important quality and functional trait of wood.However,despite the relationships between WD and abiotic factors being important to model or predict spatial distributions of functional traits,as well as responses of vegetation to climate changes,in current Earth system models or dynamic global vegetation models(ESMs/DGVMs),WD is often oversimplified,being defined as a globally uniform constant either for all plant functional types(PFTs)or for each individual PFT.Such oversimplifications may lead to simulation biases in the morphology of woody PFTs,as well as ecosystem transition and vegetation-atmosphere interactions.Moreover,existing conclusions about the relationships between WD and abiotic factors drawn from field observations remain mixed,making model parameterization improvements difficult.This study systematically investigated the influences of climate and soil factors on WD across various PFTs.Optimal fitting models for predicting WD within each PFT were then constructed by utilizing our collated global database of 138604 observations.For WDs of tree PFTs,climate emerges as a more influential factor than soil characteristics,whereas for shrub PFTs the effects of climate and soil are of equivalent significance.Across all six PFTs,correlation coefficients between predictions by fitting models and observed WD range from 0.49 to 0.93.The predicted and observed WD exhibit good agreement across climate space.It is expected that the incorporation of our research findings into DGVMs will improve the simulation of tree height and forest fractional coverage,particularly in the central forest areas and forest transition zones.
