Novel methods for managing freshwater refuges against climate change in southern Australia. Supporting Document 2: Riparian replanting for temperature control in streams

Project Page   Final Report

Southern Australia is becoming warmer and drier as climate change progresses. This creates particular threats for freshwater ecosystems that are dependent on the presence of water for their existence. This project focused on riparian vegetation and its ability to mediate water temperature by reducing input of solar radiation through shading. 

Unfortunately, resilience of freshwater ecosystems to predicted thermal shifts associated with climate change has been reduced by the widespread removal or degradation of riparian vegetation, characteristic of many temperate Australian streams. Many stream species in southern Australia are intolerant of elevated water temperatures, meaning that the maintenance of cool water refuges is critical to their sustainability, and consequently ecosystem health. In situ restoration of rivers and streams is a practical response to climate change and restoration efforts are prioritising riparian revegetation particularly in areas of current or predicted climate change. 

To assist in the determination of optimal shading regimes for refuges using riparian plantings, this study (i) established both species-specific tolerances and communitylevel thresholds of concern using existing experimental data as well as relationships between species distribution and associated environmental data, (ii) developed the scenario testing capacity of the SimpSTREAMLINE model approach for developing a riparian replanting strategy that will provide relief from high temperatures, and (iii) tested this approach for selected case studies.