[Impact of micro-landform on grassland plant comniunity structure and function in the hilly Loess Plateau region, China].

In order to analyze the impact of micro-landform on grassland plant community structure and function, species composition, aboveground and belowground biomass, and annual fine root production at different slope aspects (sunny slope and shady slope) and different slope positions (top, upper, middle and lower) were investigated in the hilly Loess Plateau region. The results showed that grassland communities were mainly composed of plants species belonging to Compositae, Poaceae and Leguminosae. The aboveground and belowground biomass and annual fine root production of community were 164.12 g · m⁻², 1044.87 g · m⁻² and 731.77 g · m⁻² · a⁻¹, respectively. Aboveground biomass, belowground biomass and annual fine root production of community were in the order of shady slope > sunny slope > top slope. In shady slope, the biomass of community under different positions were in the order of lower > middle > upper > top, but it exhibited different orders in the sunny slope compared with shady slope. Fine root mainly concentrated in the 0-20 cm top soil layer and decreased with soil depth. The average turnover time of root was 0.75 a⁻¹ and changed with soil layers and micro-landform.