REVIEW OF ECOLOGICAL RESEARCH ON IN-STREAM WOOD
森林溪流倒木生态学研究进展

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_caused). 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.