Understory bryophytes play unique and disproportionately important roles in water retention,biogeochemical cycling,and biodiversity conservation,and serve as bioindicators of environmental health in forest ecosystems....Understory bryophytes play unique and disproportionately important roles in water retention,biogeochemical cycling,and biodiversity conservation,and serve as bioindicators of environmental health in forest ecosystems.However,biogeographical research on the biomass of forest bryophytes is inadequately studied and has been limited to elevational gradients.We conducted a systematic cross-regional survey of bryophyte biomass across 413 forest sites in Sichuan Province,China.We analyzed how each environmental variable,including climatic and atmospheric factors,overstory covers,and soil nutrients,relates to bryophyte biomass and quantified their relative contributions.The results indicate that,largely similar to previous local investigations and experiments,at a large scale,bryophytes are abundant in forests with lower temperature,nitrogen deposition,vapor pressure deficit,and tree and herb covers,as well as higher light availability.Moreover,bryophyte biomass is positively associated with soil carbon and nitrogen content.These environmental variables are closely related and jointly influence bryophyte biomass,with mean annual temperature being the most significant factor(accounting for 83%of the relative contribution).The biogeographical patterns of bryophyte biomass contribute to deepening our understanding of their adaptations to multiple environmental variables and enable us to predict their responses to global climate change.These patterns also provide essential evidence for establishing more accurate terrestrial vegetation ecosystem models.展开更多
Accurate estimates of land surface characteristic parameters and turbulent heat fluxes play an important role in the understanding of land-atmosphere interaction.In this study,Fengyun-4A(FY-4A)Advanced Geostationary R...Accurate estimates of land surface characteristic parameters and turbulent heat fluxes play an important role in the understanding of land-atmosphere interaction.In this study,Fengyun-4A(FY-4A)Advanced Geostationary Radiation Imager(AGRI)satellite data and the China Land Data Assimilation System(CLDAS)meteorological forcing dataset CLDAS-V2.0 were applied for the retrieval of broadband albedo,land surface temperature(LST),radiation flux components,and turbulent heat fluxes over the Tibetan Plateau(TP).The FY-4A/AGRI and CLDAS-V2.0 data from 12 March 2018 to 30 April 2018 were first used to estimate the hourly turbulent heat fluxes over the TP.The time series data of in-situ measurements from the Tibetan Observation and Research Platform were divided into two halves-one for developing retrieval algorithms for broadband albedo and LST based on FY-4A,and the other for the cross validation.Results show the root-mean-square errors(RMSEs)of the FY-4A retrieved broadband albedo and LST were 0.0309 and 3.85 K,respectively,which verifies the applicability of the retrieval method.The RMSEs of the downwelling/upwelling shortwave radiation flux and downwelling/upwelling longwave radiation flux were 138.87/32.78 W m^(−2)and 51.55/17.92 W m^(−2),respectively,and the RMSEs of net radiation flux,sensible heat flux,and latent heat flux were 58.88 W m^(−2),82.56 W m^(−2)and 72.46 W m^(−2),respectively.The spatial distributions and diurnal variations of LST and turbulent heat fluxes were further analyzed in detail.展开更多
The central and western Tibetan Plateau(CWTP)is characterized by harsh environment and strong interactions among the spheres of earth as well as significant changes in climate and water cycles over the past four decad...The central and western Tibetan Plateau(CWTP)is characterized by harsh environment and strong interactions among the spheres of earth as well as significant changes in climate and water cycles over the past four decades.The lack of precipitation observations is a bottleneck for the study of land surface processes in this region.Over the past six years,we have designed and established two observation transects across the south-north and the west-east in this region to obtain hourly rainfall data during the warm season(May-September).The south-north transect extends from Yadong Valley on the southern slope of the Himalayas to Shuanghu County in the hinterland of the plateau,with a total of 31stations;the west-east transect extends from Shiquanhe in the west to Naqu in the central TP,with a total of 22 stations.The observation dataset has been applied to clarify the spatiotemporal characteristics of precipitation in the CWTP,to evaluate the quality of typical gridded precipitation products,to support the development of regional climate models,and to reveal the processes of summertime lake-air interactions.The observation dataset has been released in the National Tibetan Plateau Data Center.展开更多
基金supported by the National Natural Science Foundation of China(No.31600316)the Sichuan Science and Technology Program(2023NSFSC0198)。
文摘Understory bryophytes play unique and disproportionately important roles in water retention,biogeochemical cycling,and biodiversity conservation,and serve as bioindicators of environmental health in forest ecosystems.However,biogeographical research on the biomass of forest bryophytes is inadequately studied and has been limited to elevational gradients.We conducted a systematic cross-regional survey of bryophyte biomass across 413 forest sites in Sichuan Province,China.We analyzed how each environmental variable,including climatic and atmospheric factors,overstory covers,and soil nutrients,relates to bryophyte biomass and quantified their relative contributions.The results indicate that,largely similar to previous local investigations and experiments,at a large scale,bryophytes are abundant in forests with lower temperature,nitrogen deposition,vapor pressure deficit,and tree and herb covers,as well as higher light availability.Moreover,bryophyte biomass is positively associated with soil carbon and nitrogen content.These environmental variables are closely related and jointly influence bryophyte biomass,with mean annual temperature being the most significant factor(accounting for 83%of the relative contribution).The biogeographical patterns of bryophyte biomass contribute to deepening our understanding of their adaptations to multiple environmental variables and enable us to predict their responses to global climate change.These patterns also provide essential evidence for establishing more accurate terrestrial vegetation ecosystem models.
基金This research was jointly funded by the Second Tibetan Plateau Scientific Expedition and Research Pro-gram(Grant No.2019QZKK010305)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA20060101)+2 种基金the National Natural Science Foundation of China(Grant Nos.41875031,91837208,41522501 and 41275028)the Chinese Academy of Sciences Basic Frontier Sci-ence Research Program from 0 to 1 Original Innovation Project(Grant No.ZDBS-LY-DQC005-01)the Chinese Academy of Sciences(Grant No.QYZDJ-SSW-DQC019).
文摘Accurate estimates of land surface characteristic parameters and turbulent heat fluxes play an important role in the understanding of land-atmosphere interaction.In this study,Fengyun-4A(FY-4A)Advanced Geostationary Radiation Imager(AGRI)satellite data and the China Land Data Assimilation System(CLDAS)meteorological forcing dataset CLDAS-V2.0 were applied for the retrieval of broadband albedo,land surface temperature(LST),radiation flux components,and turbulent heat fluxes over the Tibetan Plateau(TP).The FY-4A/AGRI and CLDAS-V2.0 data from 12 March 2018 to 30 April 2018 were first used to estimate the hourly turbulent heat fluxes over the TP.The time series data of in-situ measurements from the Tibetan Observation and Research Platform were divided into two halves-one for developing retrieval algorithms for broadband albedo and LST based on FY-4A,and the other for the cross validation.Results show the root-mean-square errors(RMSEs)of the FY-4A retrieved broadband albedo and LST were 0.0309 and 3.85 K,respectively,which verifies the applicability of the retrieval method.The RMSEs of the downwelling/upwelling shortwave radiation flux and downwelling/upwelling longwave radiation flux were 138.87/32.78 W m^(−2)and 51.55/17.92 W m^(−2),respectively,and the RMSEs of net radiation flux,sensible heat flux,and latent heat flux were 58.88 W m^(−2),82.56 W m^(−2)and 72.46 W m^(−2),respectively.The spatial distributions and diurnal variations of LST and turbulent heat fluxes were further analyzed in detail.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grants No.2019QZKK0206)the National Key Research and Development Project(Grants No.2018YFA0605400)the National Natural Science Foundation of China(Grants No.41975125)。
文摘The central and western Tibetan Plateau(CWTP)is characterized by harsh environment and strong interactions among the spheres of earth as well as significant changes in climate and water cycles over the past four decades.The lack of precipitation observations is a bottleneck for the study of land surface processes in this region.Over the past six years,we have designed and established two observation transects across the south-north and the west-east in this region to obtain hourly rainfall data during the warm season(May-September).The south-north transect extends from Yadong Valley on the southern slope of the Himalayas to Shuanghu County in the hinterland of the plateau,with a total of 31stations;the west-east transect extends from Shiquanhe in the west to Naqu in the central TP,with a total of 22 stations.The observation dataset has been applied to clarify the spatiotemporal characteristics of precipitation in the CWTP,to evaluate the quality of typical gridded precipitation products,to support the development of regional climate models,and to reveal the processes of summertime lake-air interactions.The observation dataset has been released in the National Tibetan Plateau Data Center.
