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ABSTRACT: Aims Much research has been done on litter in forest ecosystems, but little has been done in grassland ecosystems, although litter plays an important role in grasslands. Our objectives were to determine how litter affects aboveground biomass and productivity of different functional groups and whether litter addition has a positive or negative effect in typical grassland.Methods We added litter to typical grassland after frost in October 2002. Then we sampled peak standing crop in August from 2003 to 2007. We determined productivity by species by clipping the vegetation in two 20 cm × 50 cm quadrates. SAS 9.0 was used to analyze the data.Important findings Litter addition significantly increased aboveground biomass, especially in the first year after treatment; however, no significant differences (p > 0.05) in productivity among litter addition treatments were found in the following years. Biomass was significantly different among years (p < 0.001). Effects of litter addition on each functional group were not significant (p > 0.05). PCA analysis of each functional group in different years showed that productivity depended on the competition and compensation effect between perennial bunch grasses and perennial forbs. With greater amounts of litter, the competition effect and the correlation of these two functional groups decreased.
Chinese Journal of Plant Ecology. 01/2010;