What is the rationale?
The riparian zone, representing the transition between freshwater and terrestrial ecosystems, is a unique and dynamic habitat that can support relatively high levels of biodiversity, and is thus one of particular conservation concern. The riparian zone can play a key role in the functioning of the aquatic ecosystem, affecting chemical, physical and biological processes, such as primary productivity, decomposition and ultimately inluencing community structure.

Tree cover, important particularly for its shading influence and effect on bank stability, has become widely degraded over time as a result of changes in land use, logging and livestock grazing and trampling, and river regulation. Increased stream temperature can have direct effects on poikilothermic organisms, such as fish, through changes in metabolism and ultimately mortality rates. Recently, there has been concern that this problem may be further exacerbated by the extreme summer temperatures predicted as a result of global climate change.

This review therefore seeks to bring together all available empirical evidence in order to examine the relationship between wooded riparian cover and stream temperature, and the impact on the diversity and abundance of stream biota in temperate zones.