Spatiotemporal variation of grassland aboveground biomass in Inner Mongolia from 2000 to 2019

doi:10.7523/j.ucas.2020.0047

Abstract

Abstract: Based on the acquisition of a large number of grassland aboveground biomass (AGB) field sampling data and the corresponding remote sensing indices, random forest (RF) models were constructed for different grassland types in Inner Mongolia. After validating the reliability of the models, the maximum AGB values from 2000 to 2019 were simulated. The results showed that the average annual maximum AGB was (82.74±56.34)g/m², gradually declining from northeast to southwest. The grassland types in the order of decreasing AGB:temperate meadow steppe, lowland meadow, temperate typical steppe, temperate desert steppe, temperate steppe desert, and temperate desert. From 2000 to 2019, the maximum AGB showed an overall significantly rising trend, and increased most significantly for lowland meadow and temperate typical steppe. The maximum AGB exhibited increasing trend for 70.62% of Inner Mongolia, and increased significantly for 16.28% of the area. The area with significantly increasing AGB was larger than that with significantly decreasing AGB for all the grassland types. However, the maximum AGB for all grassland types was on the fluctuant increase, and the temperature desert steppe had the largest interannual fluctuation while temperature desert the smallest. The interaction between summer air temperature and accumulated precipitation had the greatest positive effect on AGB, followed by the total precipitation from January to August, while summer air temperature had little negative effect on AGB.

Key words: grassland type, random forest model, trend variation, interannual fluctuation, climate effect

CLC Number:

S812

YUE Rongwu, ZHANG Na, WANG Jingjie, LI Zhenyu, YAN Zhihui, FENG Yiming. Spatiotemporal variation of grassland aboveground biomass in Inner Mongolia from 2000 to 2019[J]. Journal of University of Chinese Academy of Sciences, 2022, 39(1): 21-33.

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