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Posted 25 February 2009

Researchers in the US have called for the introduction of policy designed to deal with the interactions of climate change and invasive species.

In a paper published early last year in Conservation Biology Christopher Pyke and colleagues propose such policies should be based on three guiding principles:

1. Characterisation of interactions between invasive species and climate change;
2. Identification of areas where climate-change policies could negatively affect invasive-species management; and
3. Identification of areas where policies could benefit from synergies between climate change and invasive-species management.

The Invasive Species Council proposes a similar focus in Australia.

The US researchers have illustrated the interacting threats through a series of case studies, including one that looks at the potential for biofuel crops to become invasive weeds (see ISC’s Weedy Truth about Biofuels for information about this shared concern).

They also look at the threat an invasive rodent (nutria, Myocastor coypus) poses to coastal wetlands when its already destructive behaviour on the wetland ecology is teamed with climate-induced sea level rises and storms.

The researchers conclude that control and eradication of the invasive rodent should be made a priority to strengthen the functioning of coastal wetlands and flood-control structures.

The destructive behaviour of the rodent on coastal wetlands in the US is similar to the effect Australian water buffalo have on freshwater wetlands in the Northern Territory, creating swim channels and opening up these areas to inundation from salt water flooding.

The researchers point out one example in the US where the intersection between climate change and invasive species has been considered in a greenhouse-gas initiative that requires afforestation projects be “designed to promote the restoration of native forests by using mainly native species and avoiding the introduction of invasive non-native species”.

This is the sort of cross-issue consideration needed comprehensively in both climate change policy and invasive species policy.

References
Pyke, C. R., R. Thomas, R. D. Porter, J. J. Hellmann, J. S. Dukes, D. M. Lodge, and G. Chavarria. 2008. Current Practices and Future Opportunities for Policy on Climate Change and Invasive Species. Conservation Biology 22: 585-92.