青海高原温性草原对气候变化和人类活动响应动态机制研究  

Dynamic response mechanisms of temperate steppe to climate change and human activities on the Qinghai Plateau

作　　者：俞文政 周雅文 魏柱灯 姚鑫 张玉冰 YU Wenzheng;ZHOU Yawen;WEI Zhudeng;YAO Xin;ZHANG Yubing(School of Geographical Sciences,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学地理科学学院,南京210044

出　　处：《地理研究》2024年第8期1941-1957,共17页Geographical Research

基　　金：国家自然科学基金重点项目(U20A2098)。

摘　　要：温性草原作为维护青海高原草畜平衡和生态安全的重点区域,对气候变化和人类活动极为敏感。本文依托GEE平台构建长时序、高精度的草地类型数据,结合气候数据,引入随机森林模拟气候因素与温性草原间的非线性关系,对传统残差分析进行改进,以此探究青海高原温性草原的时空演变及其驱动因素。结果表明:①1987—2020年青海高原温性草原面积呈显著增长趋势,主要上升区域为共和盆地、茶卡盆地、柴达木盆地东侧等,下降区域仅占21.4%。②青海高原温性草原面积与气温和降水间呈正相关的区域占比为58.1%和67.3%,其中显著相关区域均在15%以上,可见气候的暖湿化对温性草原面积增加具有促进作用。③青海高原温性草原面积增加主要受气候变化与人类活动的共同影响,其中气候变化和人类活动相对贡献超过75%的区域分别占比33.1%和32.6%,集中于研究区东部和南部;而温性草原面积减少的主导因子为人类活动,主要分布于黄河流域,青海湖沿岸的部分区域。青海高原温性草原的时空变化及其驱动因素的定量研究结果可为草地可持续发展和政策制定提供支撑。Temperate steppe is a crucial area for maintaining the balance between grassland and livestock and ensuring ecological security on the Qinghai Plateau.It is highly sensitive to both climate change and human activities.This study constructs long-term,high-resolution grassland type data using the Google Earth Engine(GEE)platform and integrates climate data.By introducing random forest modeling to simulate the nonlinear relationship between climate factors and temperate steppe,we improve traditional residual analysis and explore the spatiotemporal evolution and driving factors of temperate steppe on the Qinghai Plateau.The results indicate that:(1)From 1987 to 2020,the temperate steppe area on the Qinghai Plateau exhibited a significant increasing trend,particularly in regions such as the Gonghe Basin,Chaka Basin,and the eastern side of the Qaidam Basin,with only 21.4%showing a decrease.(2)The proportion of areas on the Qinghai Plateau with a positive correlation of temperature and precipitation were 58.1%and 67.3%,respectively,with significant correlation areas exceeding 15%.This indicates that warmer and wetter climate conditions facilitate an increase in grassland area.(3)The increase in temperate steppe area is mainly influenced by climate change and human activities,with regions where these factors contribute over 75%covering 33.1%and 32.6%,respectively,concentrated in the eastern and southern parts of the study area.Conversely,human activities predominantly drive the decrease in grassland area,mainly in the Yellow River Basin and some areas around the Qinghai Lake.This quantitative research on the spatiotemporal changes and driving factors of temperate steppe on the Qinghai Plateau provides support for sustainable grassland development and policy formulation.

关 键 词：温性草原 驱动因素 随机森林 残差分析 青海高原 

分 类 号：P467[天文地球—大气科学及气象学] S812[农业科学—草业科学]