Latitudinal patterns of treeβ-diversity reveal important insights into the biogeographical processes that influence forest ecosystems.Although previous studies have extensively documentedβ-diversity within relativel...Latitudinal patterns of treeβ-diversity reveal important insights into the biogeographical processes that influence forest ecosystems.Although previous studies have extensively documentedβ-diversity within relatively small spatial extents,the potential drivers ofβ-diversity along latitudinal gradients are still not well understood at larger spatial extents.In this study,we determined whether treeβ-diversity is correlated with latitude in forests of southeastern China,and if so,what ecological processes contribute to these patterns of treeβ-diversity.We specifically aimed to disentangle the relative contributions from interspecific aggregation and environmental filtering across various spatial extents.We delineated regional communities comprising multiple nearby national forest inventory(NFI)plots around random focal plots.The number of NFI plots in a regional community served as a surrogate for spatial extent.We also used a null model to simulate randomly assembled communities and quantify the deviation(β-deviation)between observed and expectedβ-diversity.We found thatβ-diversity decreased along a latitudinal gradient and that this pattern was clearer at larger spatial extents.In addition,latitudinal patterns ofβ-deviation were explained by the degree of species spatial aggregation.We also identified environmental factors that driveβ-deviation in these forests,including precipitation,seasonality,and temperature variation.At larger spatial extents,these environmental variables explained up to 84%of theβ-deviation.Our results reinforce that ecological processes are scale-dependent and collectively contribute to theβ-gradient in subtropical forests.We recommend that conservation efforts maintain diverse forests and heterogeneous environments at multiple spatial extents to mitigate the adverse effects of climate change.展开更多
Climate is a key factor to determine the pattern of ecosystems;however,the latitudinal patterns of climatic variables in the arid and semiarid areas remain largely unclear when compared to humid areas.The topography o...Climate is a key factor to determine the pattern of ecosystems;however,the latitudinal patterns of climatic variables in the arid and semiarid areas remain largely unclear when compared to humid areas.The topography of the dry valleys of southwestern China plays an important role in the formation of climate.However,its impact on the climate remains qualitative.In this study,eight climatic variables from 12 meteorological stations were analyzed to explore their latitudinal patterns in the wet and dry seasons from 1961 to 2019.We also quantified the effects of local topography(RH10)on the climatic variables.The results were as follows:sunshine duration,total solar radiation,average temperature,and evaporation decreased significantly,and wind speed increased significantly with increasing latitude in the annual,wet,and dry seasons(P<0.001).Relative humidity and precipitation decreased significantly with increasing latitude in the wet season(P<0.001),and no obvious change pattern was observed in the dry season.Aridity index significantly decreased(toward dryness)with increasing latitude in the wet season and increased in the dry season(P<0.001).Wind speed had a significantly positive relationship with topography(RH10)(P<0.01),whereas precipitation and aridity index were negatively associated with topography in the wet season and positively associated with topography in the dry season.Dryness was positively associated with RH10 in the wet season,and negatively in the dry season.The results of our research could provide new perspectives for understanding the relationship between topography and drought in the dry valleys of southwestern China.展开更多
The competitor,stress tolerator,and ruderal strategy(CSR)framework has been widely applied to explain ecological processes across species.However,its utility in revealing intra-specific trade-offs and genetic adaptati...The competitor,stress tolerator,and ruderal strategy(CSR)framework has been widely applied to explain ecological processes across species.However,its utility in revealing intra-specific trade-offs and genetic adaptation to climate remains unclear.In this study,we examined whether the CSR strategy estimated by leaf traits can identify adaptations to climate in the common reed Phragmites australis.For this purpose,we integrated functional trait data from field surveys and a three-year common garden experiment to compare CSR scores between two typical populations of P.australis from western and eastern China.We further assessed the associations of CSR scores with latitude,bioclimatic factors,and phylogeographical sources using a global dataset including two invaded lineages in the North America.We found that competitor scores were positively correlated with latitude,whereas stress tolerator scores were negatively correlated.Competitor scores were positively correlated with bioclimatic factors,even when controlling for phylogeny.All CSR scores displayed significant phylogenetic signals,with the invasive lineage in the higher latitudes(haplotype M)exhibiting higher stress tolerator scores than the native lineage.Differences in competitor and stress tolerator scores between western and eastern Chinese populations of P.australis were consistent across field and common garden experiments.Although intra-species variation in CSR strategy may be influenced by phylogenetic history,our finding that CSR strategy in P.australis populations is correlated with latitude suggests these plants have adapted to local climates along a latitudinal gradient.展开更多
Comprehensive information on geographic patterns of leaf morphological traits in Chinese forests is still scarce.To explore the spatial patterns of leaf traits,we investigated leaf area(LA),leaf thickness(LT),specific...Comprehensive information on geographic patterns of leaf morphological traits in Chinese forests is still scarce.To explore the spatial patterns of leaf traits,we investigated leaf area(LA),leaf thickness(LT),specific leaf area(SLA),and leaf dry matter content(LDMC) across 847 species from nine typical forests along the North-South Transect of Eastern China(NSTEC) between July and August 2013,and also calculated the community weighted means(CWM) of leaf traits by determining the relative dominance of each species.Our results showed that,for all species,the means(± SE) of LA,LT,SLA,and LDMC were 2860.01 ± 135.37 mm2,0.17 ± 0.003 mm,20.15 ± 0.43 m2 kg–1,and 316.73 ± 3.81 mg g–1,respectively.Furthermore,latitudinal variation in leaf traits differed at the species and community levels.Generally,at the species level,SLA increased and LDMC decreased as latitude increased,whereas no clear latitudinal trends among LA or LT were found,which could be the result of shifts in plant functional types.When scaling up to the community level,more significant spatial patterns of leaf traits were observed(R2 = 0.46–0.71),driven by climate and soil N content.These results provided synthetic data compilation and analyses to better parameterize complex ecological models in the future,and emphasized the importance of scaling-up when studying the biogeographic patterns of plant traits.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
Dissolved organic matter(DOM)represents the largest pool of reactive carbon on the Earth and plays a crucial role in various biogeochemical processes and ecosystem functions.However,it is understudied for a global und...Dissolved organic matter(DOM)represents the largest pool of reactive carbon on the Earth and plays a crucial role in various biogeochemical processes and ecosystem functions.However,it is understudied for a global understanding of DOM molecular properties such as molecular weight,stoichiometry,and oxidation state,and the linkages among them across Earth systems.Here,a meta-analysis of 2707 sites in 204 literatures was conducted by synthesizing four representative molecular properties of DOM,i.e.,mass,double bond equivalent(DBE),modified aromaticity index(AI_(mod)),and nominal oxidation state of carbon(NOSC).By exploring H/C and O/C ratios,we examined the relationships among these DOM properties across waters and land systems,and their geographical patterns and environmental drivers.We found that,compared to land system,the mass,DBE,and AI_(mod) were all significantly higher in water systems,with river sediments exhibiting the highest values.The DOM oxidation state indicated by NOSC was greater on average in wastewater(NOSC=0.226±0.06)and marine water(NOSC=0.133±0.06)than in other habitats.Compared to waters,the mass in land system showed more strongly positive correlations with oxidation states such as NOSC and O/C,and the NOSC showed stronger relations to bioavailability properties such as DBE,AI_(mod),and H/C.Among all the properties,H/C and AI_(mod) contributed to the most variations in global DOM properties.In waters,NOSC monotonically increased towards high latitudes,while DBE and AI_(mod) showed significant hump-shaped patterns indicating peaked unsaturation and aromaticity at mid-latitudes of approximately absolute 30°–50°.The variations in DOM properties were significantly correlated with environmental factors such as annual mean temperature and pH.Collectively,we revealed the spatial distribution and environmental drivers of DOM molecular properties across Earth ecosystems,which could shed light on our comprehensive understanding of DOM characteristics and its dynamics.展开更多
Dissolved organic matter(DOM)is ubiquitous and contains a complex pool of thousands of distinct molecules,and their chemical characteristics help us inform the fate of global carbon.However,a more holistic perspective...Dissolved organic matter(DOM)is ubiquitous and contains a complex pool of thousands of distinct molecules,and their chemical characteristics help us inform the fate of global carbon.However,a more holistic perspective of the molecular characteristics of DOM and underlying mechanisms across Earth systems and climates remains under study.Here,we present a comprehensive analysis of the molecular characteristics of DOM using two abundance-weighted average indices,i.e.,H/C and O/C ratios,by compiling 2,995 samples from 317 studies covering waters,land,plant,petroleum,and atmosphere systems and climatic regions from the tropics to tundra.H/C ratios are lower on average in waters(H/C=1.15±0.005)and land(H/C=1.20±0.010)than in the other systems,while their O/C ratios rank between plant and atmosphere systems.In the waters and land systems,the H/C ratios of DOM vary from the highest to the lowest in the habitats of the land-to-ocean continuum generally as snow>glacier>marine≥freshwater/soil>groundwater.The H/C ratios show predictably U-shaped patterns along latitudinal gradients,indicating the lowest abundance of more hydrogen-saturated molecules at mid-latitudes of approximately 40°-50°in river water,lake water,and forest soil.The two ratios are primarily controlled by environmental factors such as pH,dissolved oxygen,and carbon and nitrogen contents.We further unveil additional and considerable links between the ratios and the extremes of climatic factors such as precipitation of warmest quarter and maximum temperature of warmest month.Our synthesis provides molecular-level perspectives to characterize the global distribution and underlying drivers of DOM,which is complementary for our understanding of global carbon cycle processes under future global change.展开更多
Leaf construction cost(LCC),a proxy for the energetic investment plants make to construct leaf biomass,indicates carbon investment strategies of plants across diverse habitats.However,large-scale variations in LCC and...Leaf construction cost(LCC),a proxy for the energetic investment plants make to construct leaf biomass,indicates carbon investment strategies of plants across diverse habitats.However,large-scale variations in LCC and their correlations with climate and soil factors have yet been fully explored.To address this knowledge gap,here,we compiled a dataset comprising 442 species-site combinations,spanning nearly all vegetation types in China.We found that LCC exhibited substantial variation,ranging from 0.72 g glucose g^(−1) to 1.93 g glucose g^(−1),with an average of 1.25 g glucose g^(−1).LCC was significantly higher in woody species compared to nonwoody species;however,there was no significant difference in LCC between evergreen and deciduous plants.LCC decreased with increasing latitude and longitude but increased with increasing altitude.Among bivariate LCC-environment relationships,LCC was positively correlated with mean annual precipitation and temperature but negatively correlated with temperature seasonality,precipitation seasonality,soil potassium content,and soil silt content.Collectively,climate and soil factors account for over 54%of the variance in LCC,with soil exerting a more significant influence than climate on LCC.This study offers an exhaustive analysis of the evident pattern of LCC over a large spatial scale,fostering a fresh perspective on functional biogeography and establishing the foundation for exploring the interplay between LCC,ecological functions,and macroevolutionary implications.展开更多
Terrestrial species are predicted to migrate northward under global warming conditions,yet little is known about the direction and magnitude of change in microbial distribution patterns.In this continental-scale study...Terrestrial species are predicted to migrate northward under global warming conditions,yet little is known about the direction and magnitude of change in microbial distribution patterns.In this continental-scale study with more than 1600 forest soil samples,we verify the existence of core microbiota and lump them into a manageable number of eco-clusters based on microbial habitat preferences.By projecting the abundance differences of eco-clusters between future and current climatic conditions,we observed the potential warming-driven migration of the core microbiota under warming,partially verified by a field warming experiment at Southwest China.Specifically,the species that favor low p H are potentially expanding and moving northward to medium-latitudes(25°–45°N),potentially implying that warm temperate forest would be under threat of soil acidification with warming.The eco-cluster of high-p H with high-annual mean temperature(AMT)experienced significant abundance increases at middle-(35°–45°N)to high-latitudes(>45°N),especially under Representative Concentration Pathway(RCP)8.5,likely resulting in northward expansion.Furthermore,the eco-cluster that favors low-soil organic carbon(SOC)was projected to increase under warming scenarios at low-latitudes(<25°N),potentially an indicator of SOC storage accumulation in warmer areas.Meanwhile,at high-latitudes(>45°N)the changes in relative abundance of this eco-cluster is inversely related with the temperature variation trends,suggesting microbes-mediated soil organic carbon changes are more responsive to temperature variation in colder areas.These results have vital implications for the migration direction of microbial communities and its potential ecological consequences in future warming scenarios.展开更多
Climate warming has substantially advanced the timing of spring leaf-out of woody species at middle and high latitudes,albeit with large differences.Insights in the spatial variation of this climate warming response m...Climate warming has substantially advanced the timing of spring leaf-out of woody species at middle and high latitudes,albeit with large differences.Insights in the spatial variation of this climate warming response may therefore help to constrain future trends in leaf-out and its impact on energy,water and carbon balances at global scales.In this study,we used in situ phenology observations of 38 species from 2067 study sites,distributed across the northern hemisphere in China,Europe and the United States,to investigate the latitudinal patterns of spring leaf-out and its sensitivity(S T,advance of leaf-out dates per degree of warming)and correlation(R_(T),partial correlation coefficient)to temperature during the period 1980-2016.Across all species and sites,we found that S_(T) decreased significantly by 0.15±0.02 d℃^(-1)°N^(-1),and R_(T) increased by 0.02±0.001°N^(-1)(both at P<0.001).The latitudinal patterns in R_(T) and S_(T) were explained by the differences in requirements of chilling and thermal forcing that evolved to maximize tree fitness under local climate,particularly climate predictability and summed precipitation during the pre-leaf-out season.Our results thus showed complicated spatial differences in leaf-out responses to ongoing climate warming and indicated that spatial differences in the interactions among environmental cues need to be embedded into large-scale phenology models to improve the simulation accuracy.展开更多
基金supported by the National Natural Science Foundation of China(42271317)the Innovation Research Team Project of the Natural Science Foundation of Hainan Province(422CXTD515)。
文摘Latitudinal patterns of treeβ-diversity reveal important insights into the biogeographical processes that influence forest ecosystems.Although previous studies have extensively documentedβ-diversity within relatively small spatial extents,the potential drivers ofβ-diversity along latitudinal gradients are still not well understood at larger spatial extents.In this study,we determined whether treeβ-diversity is correlated with latitude in forests of southeastern China,and if so,what ecological processes contribute to these patterns of treeβ-diversity.We specifically aimed to disentangle the relative contributions from interspecific aggregation and environmental filtering across various spatial extents.We delineated regional communities comprising multiple nearby national forest inventory(NFI)plots around random focal plots.The number of NFI plots in a regional community served as a surrogate for spatial extent.We also used a null model to simulate randomly assembled communities and quantify the deviation(β-deviation)between observed and expectedβ-diversity.We found thatβ-diversity decreased along a latitudinal gradient and that this pattern was clearer at larger spatial extents.In addition,latitudinal patterns ofβ-deviation were explained by the degree of species spatial aggregation.We also identified environmental factors that driveβ-deviation in these forests,including precipitation,seasonality,and temperature variation.At larger spatial extents,these environmental variables explained up to 84%of theβ-deviation.Our results reinforce that ecological processes are scale-dependent and collectively contribute to theβ-gradient in subtropical forests.We recommend that conservation efforts maintain diverse forests and heterogeneous environments at multiple spatial extents to mitigate the adverse effects of climate change.
基金supported by the National Key Research and Development Program of China(2017YFC0505105)。
文摘Climate is a key factor to determine the pattern of ecosystems;however,the latitudinal patterns of climatic variables in the arid and semiarid areas remain largely unclear when compared to humid areas.The topography of the dry valleys of southwestern China plays an important role in the formation of climate.However,its impact on the climate remains qualitative.In this study,eight climatic variables from 12 meteorological stations were analyzed to explore their latitudinal patterns in the wet and dry seasons from 1961 to 2019.We also quantified the effects of local topography(RH10)on the climatic variables.The results were as follows:sunshine duration,total solar radiation,average temperature,and evaporation decreased significantly,and wind speed increased significantly with increasing latitude in the annual,wet,and dry seasons(P<0.001).Relative humidity and precipitation decreased significantly with increasing latitude in the wet season(P<0.001),and no obvious change pattern was observed in the dry season.Aridity index significantly decreased(toward dryness)with increasing latitude in the wet season and increased in the dry season(P<0.001).Wind speed had a significantly positive relationship with topography(RH10)(P<0.01),whereas precipitation and aridity index were negatively associated with topography in the wet season and positively associated with topography in the dry season.Dryness was positively associated with RH10 in the wet season,and negatively in the dry season.The results of our research could provide new perspectives for understanding the relationship between topography and drought in the dry valleys of southwestern China.
基金supported by the National Natural Science Foundation of China(No.32100304,32470388,U22A20558,32271588).
文摘The competitor,stress tolerator,and ruderal strategy(CSR)framework has been widely applied to explain ecological processes across species.However,its utility in revealing intra-specific trade-offs and genetic adaptation to climate remains unclear.In this study,we examined whether the CSR strategy estimated by leaf traits can identify adaptations to climate in the common reed Phragmites australis.For this purpose,we integrated functional trait data from field surveys and a three-year common garden experiment to compare CSR scores between two typical populations of P.australis from western and eastern China.We further assessed the associations of CSR scores with latitude,bioclimatic factors,and phylogeographical sources using a global dataset including two invaded lineages in the North America.We found that competitor scores were positively correlated with latitude,whereas stress tolerator scores were negatively correlated.Competitor scores were positively correlated with bioclimatic factors,even when controlling for phylogeny.All CSR scores displayed significant phylogenetic signals,with the invasive lineage in the higher latitudes(haplotype M)exhibiting higher stress tolerator scores than the native lineage.Differences in competitor and stress tolerator scores between western and eastern Chinese populations of P.australis were consistent across field and common garden experiments.Although intra-species variation in CSR strategy may be influenced by phylogenetic history,our finding that CSR strategy in P.australis populations is correlated with latitude suggests these plants have adapted to local climates along a latitudinal gradient.
基金National Natural Science Foundation of China,No.31290221,No.31470506Chinese Academy of Sciences Strategic Priority Research Program,No.XDA05050702Program for Kezhen Distinguished Talents in Institute of Geographic Sciences and Natural Resources Research,CAS,No.2013RC102
文摘Comprehensive information on geographic patterns of leaf morphological traits in Chinese forests is still scarce.To explore the spatial patterns of leaf traits,we investigated leaf area(LA),leaf thickness(LT),specific leaf area(SLA),and leaf dry matter content(LDMC) across 847 species from nine typical forests along the North-South Transect of Eastern China(NSTEC) between July and August 2013,and also calculated the community weighted means(CWM) of leaf traits by determining the relative dominance of each species.Our results showed that,for all species,the means(± SE) of LA,LT,SLA,and LDMC were 2860.01 ± 135.37 mm2,0.17 ± 0.003 mm,20.15 ± 0.43 m2 kg–1,and 316.73 ± 3.81 mg g–1,respectively.Furthermore,latitudinal variation in leaf traits differed at the species and community levels.Generally,at the species level,SLA increased and LDMC decreased as latitude increased,whereas no clear latitudinal trends among LA or LT were found,which could be the result of shifts in plant functional types.When scaling up to the community level,more significant spatial patterns of leaf traits were observed(R2 = 0.46–0.71),driven by climate and soil N content.These results provided synthetic data compilation and analyses to better parameterize complex ecological models in the future,and emphasized the importance of scaling-up when studying the biogeographic patterns of plant traits.
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(Nos.U24A20578,42225708,42377122,92251304)the Basic Research Program of Jiangsu Province(No.BK20240111)+1 种基金the Key Laboratory of Lake and Watershed Science for Water Security(No.NKL2023-QN04)the Science and Technology Planning Project of Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences(No.NIGLAS2022GS09).
文摘Dissolved organic matter(DOM)represents the largest pool of reactive carbon on the Earth and plays a crucial role in various biogeochemical processes and ecosystem functions.However,it is understudied for a global understanding of DOM molecular properties such as molecular weight,stoichiometry,and oxidation state,and the linkages among them across Earth systems.Here,a meta-analysis of 2707 sites in 204 literatures was conducted by synthesizing four representative molecular properties of DOM,i.e.,mass,double bond equivalent(DBE),modified aromaticity index(AI_(mod)),and nominal oxidation state of carbon(NOSC).By exploring H/C and O/C ratios,we examined the relationships among these DOM properties across waters and land systems,and their geographical patterns and environmental drivers.We found that,compared to land system,the mass,DBE,and AI_(mod) were all significantly higher in water systems,with river sediments exhibiting the highest values.The DOM oxidation state indicated by NOSC was greater on average in wastewater(NOSC=0.226±0.06)and marine water(NOSC=0.133±0.06)than in other habitats.Compared to waters,the mass in land system showed more strongly positive correlations with oxidation states such as NOSC and O/C,and the NOSC showed stronger relations to bioavailability properties such as DBE,AI_(mod),and H/C.Among all the properties,H/C and AI_(mod) contributed to the most variations in global DOM properties.In waters,NOSC monotonically increased towards high latitudes,while DBE and AI_(mod) showed significant hump-shaped patterns indicating peaked unsaturation and aromaticity at mid-latitudes of approximately absolute 30°–50°.The variations in DOM properties were significantly correlated with environmental factors such as annual mean temperature and pH.Collectively,we revealed the spatial distribution and environmental drivers of DOM molecular properties across Earth ecosystems,which could shed light on our comprehensive understanding of DOM characteristics and its dynamics.
基金supported by National Natural Science Foundation of China(42225708,92251304,42377122,42077052)the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK0503)+2 种基金Research Program of Sino-Africa Joint Research Center,Chinese Academy of Sciences(151542KYSB20210007)Science and Technology Planning Project of NIGLAS(NIGLAS2022GS09)the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP218).
文摘Dissolved organic matter(DOM)is ubiquitous and contains a complex pool of thousands of distinct molecules,and their chemical characteristics help us inform the fate of global carbon.However,a more holistic perspective of the molecular characteristics of DOM and underlying mechanisms across Earth systems and climates remains under study.Here,we present a comprehensive analysis of the molecular characteristics of DOM using two abundance-weighted average indices,i.e.,H/C and O/C ratios,by compiling 2,995 samples from 317 studies covering waters,land,plant,petroleum,and atmosphere systems and climatic regions from the tropics to tundra.H/C ratios are lower on average in waters(H/C=1.15±0.005)and land(H/C=1.20±0.010)than in the other systems,while their O/C ratios rank between plant and atmosphere systems.In the waters and land systems,the H/C ratios of DOM vary from the highest to the lowest in the habitats of the land-to-ocean continuum generally as snow>glacier>marine≥freshwater/soil>groundwater.The H/C ratios show predictably U-shaped patterns along latitudinal gradients,indicating the lowest abundance of more hydrogen-saturated molecules at mid-latitudes of approximately 40°-50°in river water,lake water,and forest soil.The two ratios are primarily controlled by environmental factors such as pH,dissolved oxygen,and carbon and nitrogen contents.We further unveil additional and considerable links between the ratios and the extremes of climatic factors such as precipitation of warmest quarter and maximum temperature of warmest month.Our synthesis provides molecular-level perspectives to characterize the global distribution and underlying drivers of DOM,which is complementary for our understanding of global carbon cycle processes under future global change.
基金supported by the Third Xinjiang Scientific Expedition Program (Grant No. 2022xjkk1200)National Natural Science Foundation of China [32201311]Leading Plan Project of Academic Team of Minzu University of China (2024XSYL04)。
文摘Leaf construction cost(LCC),a proxy for the energetic investment plants make to construct leaf biomass,indicates carbon investment strategies of plants across diverse habitats.However,large-scale variations in LCC and their correlations with climate and soil factors have yet been fully explored.To address this knowledge gap,here,we compiled a dataset comprising 442 species-site combinations,spanning nearly all vegetation types in China.We found that LCC exhibited substantial variation,ranging from 0.72 g glucose g^(−1) to 1.93 g glucose g^(−1),with an average of 1.25 g glucose g^(−1).LCC was significantly higher in woody species compared to nonwoody species;however,there was no significant difference in LCC between evergreen and deciduous plants.LCC decreased with increasing latitude and longitude but increased with increasing altitude.Among bivariate LCC-environment relationships,LCC was positively correlated with mean annual precipitation and temperature but negatively correlated with temperature seasonality,precipitation seasonality,soil potassium content,and soil silt content.Collectively,climate and soil factors account for over 54%of the variance in LCC,with soil exerting a more significant influence than climate on LCC.This study offers an exhaustive analysis of the evident pattern of LCC over a large spatial scale,fostering a fresh perspective on functional biogeography and establishing the foundation for exploring the interplay between LCC,ecological functions,and macroevolutionary implications.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB15010300)the National Science Foundation of China(U1602234,41807316,41471218,41501282,and 31870467)+1 种基金the CAS 135 project(2017XTBG-F01)the National Key Research and Development Program(2016YFC0500702)。
文摘Terrestrial species are predicted to migrate northward under global warming conditions,yet little is known about the direction and magnitude of change in microbial distribution patterns.In this continental-scale study with more than 1600 forest soil samples,we verify the existence of core microbiota and lump them into a manageable number of eco-clusters based on microbial habitat preferences.By projecting the abundance differences of eco-clusters between future and current climatic conditions,we observed the potential warming-driven migration of the core microbiota under warming,partially verified by a field warming experiment at Southwest China.Specifically,the species that favor low p H are potentially expanding and moving northward to medium-latitudes(25°–45°N),potentially implying that warm temperate forest would be under threat of soil acidification with warming.The eco-cluster of high-p H with high-annual mean temperature(AMT)experienced significant abundance increases at middle-(35°–45°N)to high-latitudes(>45°N),especially under Representative Concentration Pathway(RCP)8.5,likely resulting in northward expansion.Furthermore,the eco-cluster that favors low-soil organic carbon(SOC)was projected to increase under warming scenarios at low-latitudes(<25°N),potentially an indicator of SOC storage accumulation in warmer areas.Meanwhile,at high-latitudes(>45°N)the changes in relative abundance of this eco-cluster is inversely related with the temperature variation trends,suggesting microbes-mediated soil organic carbon changes are more responsive to temperature variation in colder areas.These results have vital implications for the migration direction of microbial communities and its potential ecological consequences in future warming scenarios.
基金supported by the National Science Fund for Distinguished Young Scholars(Grant No.42025101)the Interna-tional Cooperation and Exchanges NSFC-STINT Project(Grant No.42111530181)+2 种基金the General Program of National Nature Science Foundation of China(Grant No.31770516)the 111 Project(Grant No.B18006)support from the Euro-pean Research Council through Synergy grant ERC-2013-SyG-610028“IMBALANCE-P”.
文摘Climate warming has substantially advanced the timing of spring leaf-out of woody species at middle and high latitudes,albeit with large differences.Insights in the spatial variation of this climate warming response may therefore help to constrain future trends in leaf-out and its impact on energy,water and carbon balances at global scales.In this study,we used in situ phenology observations of 38 species from 2067 study sites,distributed across the northern hemisphere in China,Europe and the United States,to investigate the latitudinal patterns of spring leaf-out and its sensitivity(S T,advance of leaf-out dates per degree of warming)and correlation(R_(T),partial correlation coefficient)to temperature during the period 1980-2016.Across all species and sites,we found that S_(T) decreased significantly by 0.15±0.02 d℃^(-1)°N^(-1),and R_(T) increased by 0.02±0.001°N^(-1)(both at P<0.001).The latitudinal patterns in R_(T) and S_(T) were explained by the differences in requirements of chilling and thermal forcing that evolved to maximize tree fitness under local climate,particularly climate predictability and summed precipitation during the pre-leaf-out season.Our results thus showed complicated spatial differences in leaf-out responses to ongoing climate warming and indicated that spatial differences in the interactions among environmental cues need to be embedded into large-scale phenology models to improve the simulation accuracy.
