Alien Nation
Invasive species flock to richer, more crowded European countries
A country’s wealth and population density may be more important than climate and geography when it comes to explaining the spread of invasive species, researchers say.
In a study published in the Proceedings of the National Academy of Sciences, a team analyzed data on invasive species in Europe, including plants, insects, birds, mammals, reptiles, and fungi. Areas with more than 91.1 people per square kilometer and at least $250,000 per person had the most alien species, and areas with less than 8.5 people per square kilometer had the fewest.
While geography and climate did appear to play a role in invasions, their impact was “overwhelmed by that of human variables,” the authors write. Scientists will need to give proper weight to economic factors when predicting where invasive species will strike next, the team says. – Roberta Kwok
Source: Pyšek, P. et al. 2010. Disentangling the role of environmental and human pressures on biological invasions across Europe. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1002314107.
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