中国退耕还草的土壤碳固持效应及影响因素  

Effects of grassland restoration from cropland on soil carbon sequestration and the controlling factors across China

作　　者：何奕成 胡振华 向仰州 张金鑫[1] 钱永强[1] 王迎新 许丰伟 HE Yicheng;HU Zhenhua;XIANG Yangzhou;ZHANG Jinxin;QIAN Yongqiang;WANG Yingxin;XU Fengwei(Institute of Ecological Protection and Restoration,Chinese Academy of Forestry/Grassland Research Center,National Forestry and Grassland Administration,Beijing 100091,China;College of Grassland Science and Technology,China Agricultural University,Beijing 100193,China;Forestry and Grassland Bureau of Kailu County,Tongliao City,Inner Mongolia Autonomous Region,Kailu 028400,Inner Mongolia,China;School of Geographical Resources,Guizhou Normal University,Guiyang 550018,Guizhou,China)

机构地区：[1]中国林业科学研究院生态保护与修复研究所/国家林业和草原局草原研究中心,北京100091 [2]中国农业大学草业科学与技术学院,北京100193 [3]内蒙古自治区通辽市开鲁县林业和草原局,内蒙古开鲁028400 [4]贵州师范学院地理资源学院,贵州贵阳550018

出　　处：《草业科学》2024年第2期262-270,共9页Pratacultural Science

基　　金：国家自然科学基金项目(31400620)。

摘　　要：基于检索1950-2016年发表在中国知网、Google Scholar、Web of Science等数据库的文章,筛选出关于我国退耕还草工程与土壤有机碳的文献123篇(126个研究地点)。基于筛选文献,提取了农田和恢复草地的土壤有机碳含量、土壤有效养分含量、恢复时间和气候等数据735条,旨在探究我国退耕还草工程对土壤有机碳含量的影响及其主导因素。结果表明:1)农田恢复为草地后,土壤有机碳含量呈先下降后上升趋势(时间拐点约为第6年),整体上退耕还草工程使土壤有机碳含量提高了19.8%。2)土壤有机碳的正响应随土壤深度增加而减弱,且深度超过1 m时其正响应不明显。3)土壤有效氮是影响土壤有机碳恢复的主要因素,而土壤有效磷和植物功能群对其影响不大。4)沿着增加的水分梯度,土壤有机碳的恢复效果由负变正,转变阈值为25.15 (干旱指数)。总体而言,我国退耕还草工程对土壤有机碳含量的影响为正效应,此效应受环境梯度和恢复时间的共同影响。本研究能够为我国土地利用变化背景下土壤碳库管理的相关决策提供科学依据。Based on a search of literature databases,such as CNKI,Google Scholar,and Web of Science,for the 1950-2016 period,we screened 123 articles(126 study sites)related to China’s“Grain for Green”project and soil organic carbon(SOC).In total,we extracted 735 observations from these papers at both farmland and restored grassland sites,such as SOC,soil available nutrient,restoration time,and climate.The objective was to investigate the impact of the“Grain for Green”project on SOC,as well as identify the dominant factors influencing this impact.The results indicated that,First,after the“Grain for Green”project,SOC exhibited a first decreased but then increased response along with restoration time(with a turning point at around 6 years),and the project totally enhanced SOC by 19.8%.Second,the increase of SOC weakened with increasing soil depth,and this enhancement was not significant when the depth exceeded 1 m.Third,soil available nitrogen was the main factor affecting the recovery of SOC,while soil available phosphorus and plant functional groups had a minimal impact.Fourth,along an increasing water gradient,the recovery of SOC changed from negative to positive,and the transition threshold was 25.15(aridity index).Overall,our work indicates that the“Grain for Green”project shows a positive effect on SOC,but this enhancement is jointly determined by climate and recovery time,which could provide a scientific basis for decision-making regarding land use change and soil carbon management in China.

关 键 词：退耕还草工程 土壤有机碳 土壤有效氮 土壤有效磷 水分梯度 土地利用变化 恢复效应 

分 类 号：S153.6[农业科学—土壤学]