Temporal variation in aboveground biomass of Leymus chinense steppe from species to community levels in the Xilin River basin, Inner Mongolia, China

We analyzed the long-term dynamics of aboveground biomass of Leymus chinense steppe in relation to interannual variation of precipitation and temperature during 1980-1989 at levels of community, growth form and species in the Xilin river basin, Inner Mongolia Autonomous Region, China. Annual aboveground net primary production (ANPP) varied from 154.00 g m(-2) yr(-1) in 1980 to 318.59 g m(-2) yr(-1) in 1988, with a mean of 248.63 g m(-2) yr(-1) and the coefficient of variation of 25%. ANPP was not significantly correlated to annual precipitation and total precipitation during April-September at p less than or equal to 0.05 level, but precipitation in May and August accounted for 69% of interannual variation of ANPP. The means of rain use efficiency and water use efficiency of L. chinense steppe were 8.1 kg DM ha(-1) mm(-1) yr(-1) and 0.89 mg DM g(-1) H2O respectively. Aboveground biomass of various growth forms and species had different response patterns to interannual variation of precipitation and temperature. Monthly and seasonal distribution of precipitation and temperature were the key controls of aboveground biomass of species.