What's best on the banks?

摘要

In the United States, strategies for the conservation of aquatic ecosystems emphasize the protection and restoration of streamside (riparian) forests--that is, current official policy encourages the reversion of stream-side areas to mature forest Butit has not always been thus, and throughout most of the twentieth century US government agencies have actively removed wood debris from channels to improve navigation or allow fish easier passage. These practices began to change in the 1970s, after it was recognized that the accumulation of coarse organic debris from forests leads to the greater incidence of ecologically beneficial cover, slow-water refugia and pools, and increased sediment storage.