Large wood restoration in boulder dominated streams
(English)Article in journal (Other academic) Submitted
1. An important aim of many restoration activities is to improve ecological structures and processes that have a central role for ecosystem functioning. Large wood (LW) is such a component, affecting hydraulics, channel morphology, floodplain dynamics, and ecological communities.
2. We studied the effect of in-stream wood restoration, evaluating the difference before and after wood addition using boulder restored sites as controls. We investigated channel dynamics, movement and recruitment of large wood, retention of propagules and fish communities.
3. One of three streams experienced a reduced current velocity after LW placement. The width of the channel and the reduced velocity were probably the reasons why this stream trapped most naturally drifting wood. LW sites experienced increased retention of organic matter compared to control sites, but LW proved to be unimportant in controlling brown trout density and biomass.
4. Restoring habitat heterogeneity has been widely used to enhance ecological functioning, but during the last years its potential to restore streams and rivers has been questioned. In streams affected by multiple stressors, increased habitat heterogeneity is less important. Our result demonstrates that restoration with wood can enhance the restoration made with only boulders, and as a consequence advance ecological functioning.
large wood, boulders, timber floating, river restoration, propagule retention, fish
IdentifiersURN: urn:nbn:se:umu:diva-37826OAI: oai:DiVA.org:umu-37826DiVA: diva2:370243