Predicting species responses to climate change is complicated business

In a recent publication appearing in the Journal Evolutionary Applications, the EcoGenetics Lab and collaborators used a functionally important Australian seaweed species (Hormosira banksii) as a case study to demonstrate that genetic and phenotypic differentiation may lead to uneven responses among species populations to warming sea surface temperatures. 

Sea surface temperatures in south-eastern Australia are warming at 4 times the global average, highlighting the need to understand how species can adapt to new environmental conditions. Understanding the environmental resilience of functionally important species is particularly important, given their response will have major impacts on community structure and ecosystem function.

In this study, population surveys across ~2,000 km of the species range revealed strong genetic structuring at regional and local scales reflecting extremely limited population connectivity, while common garden experiments revealed strong site differences in early development and mortality in response to elevated temperature. Notably, there was significant local scale variation in the thermal responses of embryos within regions which was corroborated by the finding of small-scale genetic differences. These differences are expected to lead to uneven responses to warming sea surface temperatures in this important marine foundation species.

The authors discuss that for locally adapted species with limited dispersal ability such as H. banksii, adaptive management strategies might be needed. These could include assisted migration of thermally adapted genotypes to populations showing signs of climate stress. Such approaches are being widely advocated as a tool for ‘climate proofing’ threatened marine and terrestrial animal and plant communities.