Abstract: Based on the generalized linear model (GLM),this study analyzed the relationship between aboveground biomass (AGB) dynamics and climatic factors in the desert and typical grassland of Inner Mongolia from May to October during the main growing season from 2009 to 2015,using MODIS vegetation index products and AGB measured in the field. The results showed that:the NDVI power function model optimally simulated AGB of Inner Mongolian desert grassland,and the RVI logarithmic function model optimally simulated AGB of Inner Mongolian typical grassland,and the average aboveground biomass of desert grassland was 6.51 Tg,and that of typical grassland was 36.94 Tg during 7 years,and the AGB variation trend of desert and typical grassland in Inner Mongolia presented a single peak curve,with the lowest value appearing in October and the maximum value appearing in July and August from 2009 to 2015.The spatial distribution of AGB from May to October was analyzed using the panel analytic method,taking August as the node to advance alternately with the seasonal change,to explain the limiting factors of the two types of grasslands. The results showed that the temperature contribution of typical grasslands was large,while the precipitation contribution of desert grasslands was large. Therefore,the hydrothermal dynamic hypothesis of climate could be used to explain this pattern.

Key words: Inner Mongolia desert and typical grassland, AGB, MODIS products, Generalized linear model, Climate

摘要： 本研究基于广义线性模型（generalized linear model，GLM），利用中分辨率成像光谱仪（moderate resolution imaging spectroradiometer，MODIS）植被指数产品和野外实测的地上生物量数据（aboveground biomass，AGB），分析了2009-2015年主要生长季5-10月内蒙古荒漠草原及典型草原AGB动态变化及气候因子的关系。结果表明：NDVI幂函数模型最佳模拟内蒙荒漠草原AGB，RVI对数函数模型最优模拟内蒙典型草原AGB；七年间荒漠草原平均地上总生物量为6.51 Tg，典型草原平均地上总生物量为36.94 Tg；2009-2015年主要生长季内蒙荒漠草原及典型草原AGB变化趋势呈现单峰曲线，生物量高峰出现在每年7，8月份，低值出现在每年10月份；AGB空间分布5-10月，以8月为节点随着季相变化南北交替推进；最后采用面板分析方法解释2类草原的限制因子，结果表明荒漠草原降水贡献较大，典型草原气温贡献较大，因此水热动态假说对该格局解释最佳。

关键词: 内蒙古荒漠草原及典型草原, AGB, MODIS产品, 广义线性模型, 气候