Above-and belowground biomass in relation to envi- ronmental factors in temperate grasslands, Inner Mongolia  

作　　者：MA WenHong1,2, YANG YuanHe1, HE JinSheng1, ZENG Hui1,2 & FANG JingYun1 1 Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China 2 School of Environment & Urban Study, Peking University Shenzhen Graduate School, Shenzhen 518055, China 

出　　处：《Science China(Life Sciences)》2008年第3期263-270,共8页中国科学（生命科学英文版）

基　　金：Supported by the National Natural Science Fundation of China (Grant Nos. 90211016, 40021101 and 30700090)

摘　　要：Above- and belowground biomasses of grasslands are important parameters for characterizing re- gional and global carbon cycles in grassland ecosystems. Compared with the relatively detailed in- formation for aboveground biomass (AGB), belowground biomass (BGB) is poorly reported at the re- gional scales. The present study, based on a total of 113 sampling sites in temperate grassland of the Inner Mongolia, investigated regional distribution patterns of AGB, BGB, vertical distribution of roots, and their relationships with environmental factors. AGB and BGB increased from the southwest to the northeast of the study region. The largest biomass occurred in meadow steppe, with mean AGB and BGB of 196.7 and 1385.2 g/m2, respectively; while the lowest biomass occurred in desert steppe, with an AGB of 56.6 g/m2 and a BGB of 301.0 g/m2. In addition, about 47% of root biomass was distributed in the top 10 cm soil. Further statistical analysis indicated that precipitation was the primary determinant factor in shaping these distribution patterns. Vertical distribution of roots was significantly affected by precipitation, while the effects of soil texture and grassland types were weak.Above- and belowground biomasses of grasslands are important parameters for characterizing re- gional and global carbon cycles in grassland ecosystems. Compared with the relatively detailed in- formation for aboveground biomass (AGB), belowground biomass (BGB) is poorly reported at the re- gional scales. The present study, based on a total of 113 sampling sites in temperate grassland of the Inner Mongolia, investigated regional distribution patterns of AGB, BGB, vertical distribution of roots, and their relationships with environmental factors. AGB and BGB increased from the southwest to the northeast of the study region. The largest biomass occurred in meadow steppe, with mean AGB and BGB of 196.7 and 1385.2 g/m2, respectively; while the lowest biomass occurred in desert steppe, with an AGB of 56.6 g/m2 and a BGB of 301.0 g/m2. In addition, about 47% of root biomass was distributed in the top 10 cm soil. Further statistical analysis indicated that precipitation was the primary determinant factor in shaping these distribution patterns. Vertical distribution of roots was significantly affected by precipitation, while the effects of soil texture and grassland types were weak.

关 键 词：TEMPERATE grasslands ABOVEGROUND BIOMASS (AGB) BELOWGROUND BIOMASS (BGB) spatial pattern vertical distribution precipitation 

分 类 号：S812[农业科学—草业科学]