Learning from Our Evolving Understanding of Biophysical Interactions to Improve River Restoration Practice.

Abstract:

Restoration of riverine habitats has largely proceeded on the assumption that by improving physical habitat, and more latterly processes, biophysical interactions will reassemble to a state similar to that prior to the disturbance event. Whilst there had been little monitoring to support this view, there is increasing evidence that the complexity of ecological systems demands a greater understanding of these biophysical interactions before we can state that a restoration has succeeded. In this paper I will draw on two examples to demonstrate the importance of understanding the spatial as well as the temporal scale of biophysical interactions. In the first example, field and modelling was used to demonstrate how different location of large wood and forest restoration can result in different hydrological outcomes. Similarly, as the forest matures it is possible to see change in restoration outcomes, extending beyond the lifetime of the project. In the second example I demonstrate how climate and land use drive the biophysical interactions within spawning salmonid habitats, research that questions accepted models used in the restoration of salmonid spawning habitat. Finally the paper reflects on the problems of restoring complex ecosystems; and points towards the need for improvements in how we research and communicate with stakeholders who ultimately live by the streams we restore.