Plant functional types and climate along a precipitation gradient in temperate grasslands, north-east China and south-east Mongolia

Using data from three field surveys along a precipitation gradient of temperate grasslands in north-east China (the Northeast China Transect, NECT) and south-east Mongolia, the spatial distribution of six plant functional types (PFTs): C-3 species, C-4 species grasses, shrubs, forbs and succulents and their relationships with climate were analysed. The spatial distribution of different PFTs varies in different regions and in different grassland types of the study area. The species richness in each PFT also has different relationships with climate (significantly or not). Generally, the number of C-3 species, C-4 species, grasses and forbs have positive relationships with precipitation and aridity. Shrubs have negative relationship with precipitation and aridity. Succulents were found to have no relationship with precipitation and aridity. Shrubs, grasses and forbs have stronger relationships with precipitation than C-3 and C-4 species. The relationships between C-3 species, forbs and aridity are more significant than with precipitation. On a regional basis, the combined effect of precipitation and temperature, the aridity, is more significantly correlated with the distribution of C-3 species and forbs, which are more dominant in the study area, than with C-4 species, grasses and succulents. (C) 2002 Elsevier Science Ltd.