• 研究报告 •

### 半干旱草原型流域植被地上生物量时空分布特征及其影响因子

1. (1内蒙古农业大学水利与土木建筑工程学院， 呼和浩特 010018；2内蒙古自治区水资源保护与利用重点实验室， 呼和浩特 010018；3Application Center for System Technologies, Fraunhofer IOSB, Ilmenau 98693, Germany)
• 出版日期:2020-02-10 发布日期:2020-02-10

### Temporal and spatial distribution of aboveground biomass of vegetation and quantitative analysis of impact factors in semi-arid grassland basin.

ZHANG Jun-yi1, LIU Ting-xi1,2*, LUO Yan-yun1,2, DUAN Li-min1,2, LI Wei1, YANG Lu1, Buren Scharaw3

1. 1College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China;2Inner Mongolia Water Resource Protection and Utilization Key Laboratory, Hohhot 010018, China; 3Application Center for System Technologies, Fraunhofer IOSB, Ilmenau 98693, Germany)
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• Online:2020-02-10 Published:2020-02-10

Abstract: Xilin River Basin is the most representative area of typical steppe in Inner Mongolia. Characterizing the dynamics of aboveground biomass and its relationship with environmental factors can provide basic data for the research of ecosystem carbon cycling and a theoretical frame for rational use and management of grassland. Xilin River Basin locates in semiarid region. With filed empirical data, the methods of correlation analysis, classification and regression tree, nonlinear regression analysis were used to quantitatively analyze the relationship between aboveground biomass and its key driving factors in the upstream and downstream of the basin at different times (around June 20, July 5, July 20, and August 6 of 2016). The results showed that: (1) Aboveground biomass changed most significantly in July, with a peak on August 6. The aboveground biomass of the upper, middle and lower basin on August 6 were 79.64, 74.87, 69.34 g·m-2 respectively. Biomass showed a decreasing tendency from the southeast to the northwest. (2) Key factors affecting aboveground biomass at different times in the upstream of the basin were precipitation in April, soil water content on July 5, soil water content on July 20, and Simpson index on August 6. The Simpson index had a negative effect on aboveground biomass, while all other factors had positive effects on aboveground biomass. Corresponding key factors accounted for 77%, 72%, 79%, and 65% of the variation of aboveground biomass, respectively. (3) Longitude, precipitation in June, precipitation in July, and precipitation in July were the key factors affecting aboveground biomass of the downstream on June 20, July 5, July 20, and August 6, respectively. All the factors had a significant positive correlation with aboveground biomass. Corresponding key factors accounted for 88%, 75%, 85%, and 82% of the variation of aboveground biomass, respectively. Our results provide a reference for the analysis of the temporal and spatial variation of plant biomass at a large scale and provide data for in depth research and long-term monitoring of grasslands.