Abstract: This study on litter decomposition of Potentilla fruticosa shrub and Kobresia humilis meadow in Qinghai Tibet plateau was carried out at the Haibei research station from Oct.of 1997 to Dec.of 1999.The decomposition rates were assessed by using litter bag method.Samples were retrieved at regular intervals,and the weightlessness of samples was measured.The results shown as follows: 1. The litter decomposition rates of two kinds vegetation types were shown a significant seasonal dynamics,with a fast litter mass loss in the first three months and there were no obvious increase in the litter mass loss during late five months.2. Comparison of the litter decomposition rate between two kinds vegetation types was indicated that the decomposition rate of Kobresia humilis meadow was obviously higher than that of Potentilla fruticosa shrub(P<0.01).3. The soil temperature,the numbers of microorganism and the chemical composition of litter itself are the main factors what affect the litter decomposition rate.4. Comparison between the decomposition rate of litter and different feces was shown that the decomposition rates of feces were much lower than that of litters.

Key words: Potentilla fruticosa Shrub, Kobresia humilis meadow, Decomposition rate, Litter, Microbial biomass, Animal feces

摘要： 研究青藏高原金露梅灌丛和矮嵩草草甸两种植被类型枯枝落叶分解作用强度及其随着埋放时间延长的变化规律.结果表明,两种植被的枯枝落叶在埋放的前3个月均显示出明显的分解效果.其总分解率分别达到20.31%和30.4%,随后分解率逐渐降低,埋放后个月的总分解率仅为前3个月的37.60%和39.33%.矮嵩草草甸枯枝落叶的分解率显著高于金露梅灌丛.土壤温度、微生物数量和枯枝落叶本身的化学成分是影响分解率的主要因素.与其相比,动物粪便的分解率很低.

关键词: 金露梅灌丛, 矮嵩草草甸, 分解率, 枯枝落叶, 微生物生物量, 动物粪便