The aboveground biomass of desert steppe and its spatiotemporal variation in western Inner Mongolia

作     者：Tian Gao Bin Xu XiuChun Yang YunXiang Jin HaiLong Ma JinYa Li HaiDa Yu 

作者机构：Key Laboratory of Agri-informatics Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences 

出 版 物：《Research in Cold and Arid Regions》 (寒旱区科学（英文版）)

年 卷 期：2013年第5卷第3期

页      面：339-346页

核心收录：

学科分类：08[工学] 09[农学] 0903[农学-农业资源与环境] 0834[工学-风景园林学（可授工学、农学学位）] 

基　　金：supported by the National High Technology Project "863" (Nos. 2006AA10Z242, 2008AA121805) National Natural Science Foundation of China (NSFC, 40701055) 

主　　题：Inner Mongolia desert steppe normalized difference vegetation index （NDVI） aboveground biomass climate factors 

摘      要：A precise understanding of the aboveground biomass of desert steppe and its spatio-temporal variation is important to understand how arid ecosystems respond to climate change and to ensure that scarce grassland resources are used rationally. On the basis of 756 ground survey quadrats sampled in western Inner Mongolia steppe in 2005-2011 and remote sensing data from the Moderate Resolu- tion Imaging Spectroradiometer （MODIS）--the normalized difference vegetation index （NDVI） dataset for the period of 2001-2011--we developed a statistical model to estimate the aboveground biomass of the desert steppe and further explored the rela- tionships between aboveground biomass and climate factors. The conclusions are as follows： （1） the aboveground biomass of the steppe in the research area was 5.27 Tg （1 Tg=1012 g） on average over 11 years; between 2001 and 2011, the aboveground biomass of the western Inner Mongolia steppe exhibited fluctuations, with no significant trend over time; （2） the aboveground biomass of the steppe in the research area exhibits distinct spatial variation and generally decreases gradually from southeast to northwest; and （3） the important factor causing intemnnual variations in aboveground biomass is precipitation during the period from January to July, but we did not find a significant relationship between the aboveground biomass and the corresponding temperature changes. The precipitation in this period is also an important factor influencing the spatial distribution of aboveground biomass （R2=0.39, P〈0.001）, while the temperature might be a minor factor （R2=0.12, P〈0.01 ）. The uncertainties in our estimate are primarily due to uncertainty in converting the fresh grass yield estimates to dry weight, underestimates of the biomass of shrubs, and error in remote sensing dataset.