中文摘要：

溪流倒木是指在河流中长度大于1 m、直径大于10 cm的死木.溪流倒木在森林河流中（特别是较小的河流中）是一个常见且重要的结构成分.该文综述了近30年溪流倒木的研究成果（主要来自北美）,总结溪流倒木在河流形态、碳循环、泥沙与养分拦截、水生生境的形成、水生生物多样性等方面的生态功能,倒木的时间动态性与空间变异性,以及干扰（包括自然干扰与人为干扰）与倒木存留量及分布的关系.此外,该文也探讨了溪流倒木的生态管理模式及未来研究方向.大量的研究证明,溪流倒木对森林水生生态系统具有重要的生态功能,但它的存留量、分布以及它的生态意义因所研究的森林生态系统、河流大小不同而异.随着河流宽度的增加, 倒木的存留量及它对河流的影响减少,并且倒木的分布以单个为主变为聚集体为主.单个倒木的直径则随河流宽度增加而增大.倒木也呈现十分明显的时间动态性,而这种动态往往是由大规模毁灭性的森林干扰（火、风倒等）所驱动的.研究倒木的时空变异性及自然干扰与人为干扰对倒木的不同影响对于保持倒木的生态功能是十分必要的.该文还对中国开展溪流倒木的生态研究提出一些建议.

英文摘要：

In-stream wood is defined as dead wood （ 〉 10 cm diameter and 〉 1 m length） in the stream channel. In-stream wood is a common, but important structural component in forest streams, particularly in relatively small creeks. Through review of research from the last 30 years （mainly from North America）, we synthesize information on in-stream wood ecological functions （on channel morphology, nutrient cycling, sediment storage, aquatic habitat and biodiversity）, dynamics, spatial variation and relationship between in-stream wood （loadings and distribution） and disturbance （natural and human-cansed）. We also present wood management paradigms and future research directions. Much research has demonstrated that in-stream wood has important ecological functions for aquatic ecosystems. In-stream wood can significantly change channel morphology through its role in intercepting sediments and water flow as well as stabilizing stream banks. Many aquatic habitat features such as pool, cover and substrate are positively related to in-stream wood characteristics. In-stream wood also affects nutrient cycling through its decomposition and interception of fine organic materials （ e. g., tree needles and branches）. Because of these ecological functions, in-stream wood supports greater aquatic biodiversity and productivity. However, its ecological significance largely depends on types of forested watersheds and sizes of streams. As stream sizes increase, wood loading and its influence generally decrease. The size of individual wood pieces, however, increases with increasing stream size. In-stream wood also has large temporal variations or dynamics which are mainly driven by large-scale catastrophic forest disturbance （i. e., fire, windthrow, etc）. Understanding spatial and temporal variations and differences between natural and human disturbances is important for protecting and maintaining wood ecological functions. We provide suggestions for future in-stream wood ecological research in China.