Spatial-temporal dynamics of alpine grassland coverage and its response to climate warming in Mt.Qomolangma Nature Preserve during 2000-2019  

作　　者：MA Fei PENG Pei-hao 

机构地区：[1]College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China

出　　处：《Journal of Mountain Science》2022年第8期2297-2311,共15页山地科学学报（英文）

基　　金：supported by the Second Tibetan Plateau Scientific Expedition and Research Program(Grant Nos.2019QZKK0301 and 2019QZKK0307)。

摘　　要：The Qinghai-Tibet Plateau(QTP)has the largest and highest alpine grassland ecosystem in the world,which is considered to be the most sensitive and vulnerable ecosystem to climate change.Its dynamic changes and driving mechanism have always been widely researched.The Qomolangma National Nature Preserve(QNNP),with the largest altitude difference in the world,was selected as the study area to analyse the spatial-temporal dynamics of grassland coverage and the different characteristics of elevation gradients at the southern slope(SS)and northern slope(NS)with MODIS MOD13Q1 NDVI and MOD11A2 land surface temperature data from 2000to 2019 using the Mann-Kendall trend test and Theil-Sen slope methods.Further,the response mechanism of grassland coverage to climate warming is discussed.The results revealed that from 2000 to 2019,the grassland coverage change in the study area is mainly stable.The increased area proportion of grassland coverage on the southern slope is significantly higher than that on the northern slope,and the decreased area proportion of grassland coverage on the northern slope is significantly greater than that on the southern slope.The change characteristics of grassland coverage in the QNNP exhibit an obvious elevation gradient;the higher the elevation,the greater the increased area proportion of grassland coverage,particularly on the SS.The land surface temperature can be used as a proxy for analysing the temporal and spatial variation trends of air temperature in the QNNP.With the increase of the altitude,the land surface temperature rise rate on both the southern slope and northern slope exhibited an increasing trend,and the sensitivity of grassland coverage to temperature rise was higher on the northern slope.The water condition was the decisive factor for the horizontal and vertical spatial heterogeneity of the dynamic change of grassland coverage,and the melting of glaciers and thawing of permafrost were important sources of water for grassland growth in the QNNP.Climate warming promotes the gro

关 键 词：Alpine grassland Global warming Vegetation dynamic Elevation gradient Qomolangma 

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]