气候变化下中国植被GPP与土壤水的互馈关系  

Mutual feedback relationship between vegetation GPP and soil moisture in China under climate change

作　　者：罗敏 孟凡浩 王云倩 萨楚拉[1,2] 包玉海[1,2] 刘铁[4] LUO Min;MENG Fanhao;WANG Yunqian;SA Chula;BAO Yuhai;LIU Tie(College of Geographical Science,Inner Mongolia Normal University,Hohhot 010022,China;Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information Systems,Inner Mongolia Normal University,Hohhot 010022,China;School of Geography and Tourism,Qufu Normal University,Rizhao 276826,Shandong,China;Xinjiang Institute of Ecology and Geography,CAS,Urumqi 830011,China)

机构地区：[1]内蒙古师范大学地理科学学院,呼和浩特010022 [2]内蒙古自治区遥感与地理信息系统重点实验室,呼和浩特010022 [3]曲阜师范大学地理与旅游学院,日照276826 [4]中国科学院新疆生态与地理研究所,乌鲁木齐830011

出　　处：《地理学报》2024年第1期218-239,共22页Acta Geographica Sinica

基　　金：国家自然科学基金(42101030,42261079);内蒙古高校青年科技英才项目(NJYT22027,NJYT23019);内蒙古师范大学基本科研业务费项目(2022JBBJ014,2022JBQN093);第三次新疆综合科学考察项目(2021xjkk1400)。

摘　　要：土壤水是影响植被生长发育的关键驱动因素,而植被又通过蒸散发等过程反作用于土壤水。深入探究土壤水和植被GPP的相互作用关系对生态系统可持续发展及水资源的高效利用至关重要。本文基于MODIS GPP、ERA5-Land土壤水等数据,采用改进的非线性Granger因果模型、二阶偏相关分析、趋势分析等方法,解析2000—2021年中国不同植被区GPP与土壤水协同演变规律及互馈关系。研究结果表明:①2000年以来中国50.89%~57.61%的植被区呈GPP增加协同土壤水减少趋势,且该协同变化趋势占比随土层深度加深而增加;②59.88%~79.38%植被区GPP与土壤水表现为双向Granger因果关系,且面积占比随深度加深而减少。③GPP增加对100~289 cm土壤水消耗更加明显(57.03%)且滞后效应更长(2.15个月)。深度小于100 cm的土壤水对GPP增加主要呈促进作用(71.43%~76.58%),仅在天山及横断山区等部分区域出现抑制作用;而100~289 cm土壤水对植被GPP的促进作用(48.31%)减弱并伴随滞后期显著延长(2.92个月)。④二者相互作用关系在降水量介于200~400 mm时最为显著,随降水量增加二者关系逐渐减弱。而不同温度梯度对二者相互作用的影响呈多重阈值效应。本文深化了对气候变化背景下陆地生态系统碳—水循环相互作用的理解,能够对未来生态修复工程的实施及生态系统可持续发展提供重要的理论参考。Soil moisture is a key driving factor that affects vegetation growth.Vegetation reacts to soil moisture through processes such as evapotranspiration.In-depth exploration of the interaction between soil moisture and vegetation GPP is crucial to ensuring the sustainable development of ecosystems and the efficient utilization of water resources.This study employed MODIS GPP,ERA5-Land soil moisture,and other data sources.It utilized an enhanced nonlinear Granger causality model,along with partial correlation analysis,Sen's slope,and the Mann-Kendall method.These methods were used to examine the combined changes in GPP and soil moisture and their mutual feedback relationship across diverse vegetation types in China from 2000 to 2021.The results showed that:(1)Since 2000,50.89%-57.61% of the vegetated areas in China have shown a synergistic trend of increasing GPP and decreasing soil moisture,which exhibited a greater proportion with increasing soil depth.The proportion of areas with consistently increasing trends in both GPP and soil moisture was 39.03%-45.76%.(2)In 59.88%-79.38% of vegetated areas,both GPP and soil moisture showed a bidirectional Granger causal relationship.This proportion decreased with soil depth,notably in temperate grassland areas(R6)and temperate desert regions(R7).(3)The increase in GPP resulted in a more significant consumption(57.03%)of soil moisture at 100-289 cm depth and a longer lag effect(2.15 months).Soil moisture at a depth of less than 100 cm mainly promoted the increase in GPP(71.43%-76.58%)and only showed inhibitory effects in some areas,such as the Tianshan Mountains and Hengduan Mountains.The promoting effect of soil moisture at 100-289 cm depth on the vegetation GPP(48.31%)weakened and was accompanied by a significant increase in the lag effect(2.92 months).(4)As the precipitation increased,the interaction between vegetation GPP and soil moisture gradually decreased.When the precipitation was between 200 mm and 400 mm,the interaction was most significant.The influence of differen

关 键 词：土壤水 GPP 协同演变 互馈关系 滞后效应 

分 类 号：Q948[生物学—植物学] P467[天文地球—大气科学及气象学] X171.1[环境科学与工程—环境科学]