关键词: 温带草原, 根冠比, 年均温, 年降水, 土壤含水率

Abstract: Grasslands play a significant role in terrestrial ecosystem carbon cycle due to large biomass stored belowground. R : S ratio (belowground to aboveground biomass ratio) has been widely used for estimating root biomass. However, there was a gap for the estimation of R : S ratio in regional or large scale. Therefore, it is necessary to provide R : S ratio data for a wide range of community types, which will improve the accuracy of carbon budget and root biomass estimate. Here the authors synthesized field biomass data from 113 sites and conducted regression analysis between R : S ratio and environmental variables in Inner Mongolia temperate steppe, aiming to illustrate spatial variations of R : S ratio and their regulating factors. The results showed that overall aboveground and belowground biomass of the temperate steppe averaged 135.3 and 775.2g·m^-2, respectively. R : S ratio varied from 5.2 to 6.7 in different steppe, with median value 6.3. No significant relationships were found between R : S ratio and mean annual temperature, soil water content, annual precipitation and steppe types.

Key words: temperate steppe, R : S ratio, mean annual temperature, annual precipitation, soil water content