Most ecosystems are undergoing threats from multiple sources. Understanding how these threats combine to drive ecosystem and biodiversity responses is a must for making sensible decisions about how to combat these threats. Land-use change and climate change are major drivers of ecosystem change and can combine to have enexpectedly large impacts on biodiversity if they act together synergistically. In a forthcoming paper in the Journal of Applied Ecology, Chrystal Mantyka-Pringle and co-authors explore this issue for freshwater systems.
In a study based in South East Queensland, Australia they show that the combined effects of climate change and land-use change are likely to have relatively small impacts on the richness of fish and macroinvertebrates at regional scales.
However, the combined impacts at the scale of individual sites can be very large, but also variable from site to site. Potential mitigation options include reducing in-stream nutrients, slowing terrestrial runoff, an providing shade, including riparian restoration. However, the need for mitigation measures at sites will vary and depend on the site scale charactersitics that determine the combined level of threat.