Edition 5, June 2010
Climate Thaw Will Unlock New Areas For Coolatai Grass
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June 18th, 2010
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| Coolatai grass. Image source |
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Under climate change, the invasive Coolatai grass (Hyparrhenia hirta) is likely to spread into new areas, with coastal Queensland, most of NSW, Central and South America, sub-Saharan Africa, Mexico, the Caribbean and south-eastern USA at particular risk.
On the basis of modelling (using the CLIMEX program), VK Chejara and co-researchers found that the grass is likely to invade areas currently too cold for its survival and contract from areas expected to become drier, such as inland Australia.
Introduced in the 1890s to the Coolatai district of northern NSW for pasture and erosion control, Coolatai grass is a serious environmental weed in Australia, and many other countries. It often forms monocultures with a dense growth of leaves and stems.
Even under existing climates, its potential invasive range is “vast and far greater than the current distribution, with suitable climate conditions extending over much of the tropics and subtropics”.
A rapidly changing climate is likely to benefit invasive species such as Coolatai grass because it can extend its range quickly and tolerate a wide range of climatic conditions, outcompeting native species.
References
Chejara VK, Kriticos DJ, Kristiansen P, Sindel BM, Whalley RDB and Nadolny C. 2010. The current and future potential geographical distribution of Hyparrhenia hirta. Weed Research 50(2): 174-184.