Climate Change Implications for River Restoration in Global Biodiversity Hotspots
Davies, PM. 2010. Climate Change Implications for River Restoration in Global Biodiversity Hotspots. RESTORATION ECOLOGY 18 (3): 261-268.
This is an opinion article considering how climate change trends will influence rivers in Southwestern Australia, a global biodiversity hotspot. The paper provides a useful chart summarizing specific climate change trends and their projected impacts on rivers.
Davies primarily uses this paper to profile his own work modeling a potential climate mitigation strategy, which he terms “over-restoration.” He makes the point that with global change upon us, restoring sites to historic conditions may not be sufficient to protect temperature limited aquatic species. Thus, river restoration should focus on planting vegetation around streams – with a priority on channel areas in east-west running streams, in order to maximize shade benefits. He claims that 10% of increased shade is required for every 1◦C rise in temperature.
I am skeptical of this approach, as it does not address the potential for increased evapo-transporation, which would add to the drying and warming effects of climate change on streams. Neither does this paper address the high levels of disturbance to be expected for vegetation planted within stream channels. Davies should have addressed these concerns and considered other restoration approaches in more detail, not simply his own modeling findings.