Divergent contributions of spring and autumn photosynthetic phenology to seasonal carbon uptake of subtropical vegetation in China  

作　　者：PENG Ying LI Peng ZHOU Xiaolu LUO Yunpeng ZHANG Cicheng WANG Longjun LI Tong PENG Changhui 

机构地区：[1]School of Geographic Sciences,Hunan Normal University,Changsha,410081,China [2]Department for Biogeochemical Integration,Max-Planck-Institute for Biogeochemistry,Jena,07745,Germany [3]Department of Biology Sciences,Institute of Environment Sciences,University of Quebec at Montreal,C.P.8888,Succ.Centre-Ville,Montreal,H3C 3P8,Canada

出　　处：《Journal of Geographical Sciences》2024年第7期1280-1296,共17页地理学报（英文版）

基　　金：National Natural Science Foundation of China,No.42371121;Joint Fund for Regional Innovation and Development of the National Natural Science Foundation of China,No.U22A20570;Science and Technology Innovation Program of Hunan Province,China,No.2022RC4027。

摘　　要：Phenological changes play a central role in regulating seasonal variation in the ecological processes,exerting significant impacts on hydrologic and nutrient cycles,and ultimately influencing ecosystem functioning such as carbon uptake.However,the potential impact mechanisms of phenological events on seasonal carbon dynamics in subtropical regions are under-investigated.These knowledge gaps hinder from accurately linking photosynthetic phenology and carbon sequestration capacity.Using chlorophyll fluorescence remote sensing and productivity data from 2000 to 2019,we found that an advancement in spring phenology increased spring gross(GPP)and net primary productivity(NPP)in subtropical vegetation of China by 2.1 gC m^(-2)yr^(-1)and 1.4 gC m^(-2)yr^(-1),respectively.A delay in autumn phenology increased the autumnal GPP and NPP by 0.4 gC m^(-2)yr^(-1)and 0.2 gC m^(-2)yr^(-1),respectively.Temporally,the contribution of the spring phenology to spring carbon uptake increased significantly during the study period,while this positive contribution showed a nonsignificant trend in summer.In comparison,the later autumn phenology could significantly contribute to the increase in autumnal carbon uptake;however,this contributing effect was weakened.Path analysis indicated that these phenomena have been caused by the increased leaf area and enhanced photosynthesis due to earlier spring and later autumn phenology,respectively.Our results demonstrate the diverse impacts of vegetation phenology on the seasonal carbon sequestration ability and it is imperative to consider such asymmetric effects when modeling ecosystem processes parameterized under future climate change.

关 键 词：SUBTROPICS vegetation phenology remote sensing carbon cycle climate change 

分 类 号：P467[天文地球—大气科学及气象学] Q948[生物学—植物学]