作　　者： ; ; ; ;

机构地区： 内蒙古农业大学生态环境学院

出　　处： 《植物生态学报》 2010年第8期907-914,共8页

摘　　要： 通过连续5年对退化草地进行凋落物添加处理,分析不同处理强度植物群落动态,探讨凋落物对草地地上和不同功能群生产力的影响。结果表明:凋落物添加对草地地上生产力有显著的促进作用,草地地上生产力随着凋落物添加强度的增加而变化不大。处理效应主要表现在处理后第一年,重度处理与对照有极显著差异(p<0.05),以后几年差异不显著(p>0.05),年度间差异极显著(p<0.001)。凋落物添加对植物群落各功能群生产力无显著影响。年度间不同处理各功能群相对生物量随年际变化的主成分分析(PCA)结果说明:草地生产力主要是由多年生丛生型禾草与多年生杂类草在生态系统中的竞争补偿作用决定的,随着凋落物添加强度的增加,二者的竞争作用减弱,相关性下降,多年生丛生型禾草占更大优势,预示着多年生杂类草与一二年生草本、灌木、多年生根茎型禾草的竞争补偿作用增大。 Aims Much research has been done on litter in forest ecosystems,but little has been done in grassland ecosys-tems,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.

关 键 词： 补偿 竞争 功能群 凋落物 生产力

领　　域： [农业科学] [农业科学] [农业科学]