Novel methods for managing freshwater refuges against climate change in southern Australia. Supporting Document 2: Riparian replanting for temperature control in 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 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 community-level thresholds of concern, (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.The relative proportion of temperature-sensitive, tolerant and very tolerant taxa changed among multiple pairs of shaded and unshaded sites, suggesting that upper thermal threshold data for stream invertebrates can be used to set biodiversity targets for stream restoration aimed at temperature control. The approach developed in this study to set biodiversity targets for stream restoration could be used across southern Australia to assess whether planned restoration activities, aimed at mitigating against rising water temperatures, will provide for biodiversity outcomes.