Climate change opens new avenue for spread of invasive plants

University of Florida: Plants that range northward because of climate change may be better at defending themselves against local enemies than native plants. So concludes a team of scientists including a University of Florida geneticist. The team’s findings, reported in today’s online edition of Nature, suggest that certain plants could become invasive if they spread to places that were previously too cold for them.

“This paper is the first to suggest that the mechanisms that aid invasive species when they move from one continent to the next may actually work within continents when climate change gradually extends the distributional range of a species,” said Koen J.F. Verhoeven, an evolutionary biologist at The Netherlands Institute of Ecology. “Plants may be able to outrun, so to speak, their enemies from the southern range.”

Often, exotic plants and animals are introduced to new continents or geographic regions by travelers and commerce. Separation from their natural enemies can drive their invasive success in the new range. But, increasingly, the distribution of many species is shifting because of climate change and changes in land use.

…Scientists grew six exotic and nine native plant species in pots with field-collected soil from the Millingerwaard area, allowing natural soil pathogenic microbes to accumulate in the pots. Then they removed the plants and replanted the soils with the same plant species. The growth of native plants was reduced far more than the growth of exotic species, indicating natives were more vulnerable to natural soil-borne microbes…..

A field in Port Gibson, Mississippi, engulfed by kudzu. Shot by Gsmith, Wikimedia Commons, under the terms of the GNU Free Documentation License, Version 1.2