The grassland in the Hindu Kush Himalayan(HKH)region is one of the largest and most biodiverse mountain grassland types in the world,and its ecosystem service functions have profound impacts on the sustainable development of the HKH region.Monitoring the spatiotemporal distribution of grassland aboveground biomass(AGB)accurately and quantifying its response to climate change are indispensable sources of information for sustainably managing grassland ecosystems in the HKH region.In this study,a pure vegetation index model(PVIM)was applied to estimate the long-term dynamics of grassland AGB in the HKH region during 2000-2018.We fur-ther quantified the response of grassland AGB to climate change(temperature and precipitation)by partial correlation and variance par-titioning analyses and then compared their differences with elevation.Our results demonstrated that the grassland AGB predicted by the PVIM had a good linear relationship with the ground sampling data.The grassland AGB distribution pattern showed a decreasing trend from east to west across the HKH region except in the southern Himalayas.From 2000 to 2018,the mean AGB of the HKH region in-creased at a rate of 1.57 g/(m2·yr)and ranged from 252.9(2000)to 307.8 g/m2(2018).AGB had a positive correlation with precipita-tion in more than 80％of the grassland,and temperature was positively correlated with AGB in approximately half of the region.The change in grassland AGB was more responsive to the cumulative effect of annual precipitation,while it was more sensitive to the change in temperature in the growing season;in addition,the influence of climate varied at different elevations.Moreover,compared with that of temperature,the contribution of precipitation to grassland AGB change was greater in approximately 60％of the grassland,but the differences in the contribution for each climate factor were small between the two temporal scales at elevations over 2000 m.An accurate assessment of the temporal and spatial distributions of grassland AGB and the quantification of its response to climate change are of great significance for grassland management and sustainable development in the HKH region.

XU Cong;LIU Wenjun;ZHAO Dan;HAO Yanbin;XIA Anquan;YAN Nana;ZENG Yuan

State Key Laboratory of Remote Sensing Science,Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Ecology and Environmental Sci-ences&Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments,Yunnan University,Kun-ming 650091,China;College of Life Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;CAS Center for Excellence in Tibetan Plateau Earth Sciences,Chinese Academy of Sciences,Beijing 100101,China;Beijing Yanshan Earth Critical Zone National Research Station,University of Chinese Academy of Sciences,Beijing 101408,China;College of Resources and Envir-onment,University of Chinese Academy of Sciences,Beijing 100049,China

中国地理科学（英文版）

[1]XU Cong;LIU Wenjun;ZHAO Dan;HAO Yanbin;XIA Anquan;YAN Nana;ZENG Yuan-.Remote Sensing-based Spatiotemporal Distribution of Grassland Aboveground Biomass and Its Response to Climate Change in the Hindu Kush Himalayan Region)[J].中国地理科学（英文版）,2022(05):759-775

HKH,PVIM,titioning

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