中文摘要：

凋落物分解是干旱半干旱区重要的生化过程，也是区域内物质周转与能量流动的关键生态环节，主要受气候、凋落物基质质量（简称凋落物质量）和土壤生物群落等因素的综合影响．本文综合评述了非生物因素（温度、降水、光辐射、土壤有机质等）和生物因素（凋落物质量、土壤微生物、种群组成和群落结构等）对干旱半干旱地区凋落物分解的影响的相关研究进展．在诸多影响因素中，降水与光辐射是最重要的限制因素．降水能够在短期内使凋落物分解速率迅速增加，而干旱半干旱区光照强度大、时间长，uV—B引起的光矿化效应能较好地解释区域内凋落物分解规律．凋落物质量和群落结构主要受生态系统类型的影响，属于长期效应．今后凋落物生态研究的重点主要为全球气候变化下各环境因素的交互作用，不同尺度下凋落物分解过程与格局的变化，以及多因素交互作用凋落物分解模型的构建等方面．

英文摘要：

Litter decomposition is one of the important biochemical processes in arid and semi-arid regions, and a key component of regional nutrient turnover and carbon cycling, which is mainly af- fected by climate, litter quality, and decomposer community. In order to deeply understand the re- lationships between litter decomposition and environmental factors in arid and semi-arid regions, this paper summarized the research progress in the effects of abiotic factors （soil temperature, pre- cipitation, and ultraviolet-B radiation） and biotic factors （litter quality, soil microbial and animal composition and community structure） on the litter decomposition in these regions. Among the fac- tors, precipitation and ultraviolet-B radiation are considered to be the main limiting factors of litter decomposition. In arid and semi-arid regions, precipitation can significantly increase the litter de- composition rate in a short term, while the photo-degradation induced by ultraviolet-B radiation, due to the strong and long-term radiation, can increase the decomposition rate of terrestrial litter. Litter quality, soil microbial and animal composition and community structure are mainly affected by the type of ecosystems in a long term. However, the affecting mechanisms of these environmental factors on litter decomposition are still not very clear. It was suggested that the future litter ecologi- cal research should be paid more attention to the interaction of environmental factors under climate change, the variations of litter decomposition at different spatial scales, and the establishment of lit- ter decomposition models in relation to the synergistic interactions of multiple factors.