Exotic plant species alter ecosystem productivity

In their joint publication in the journal Ecology Letters German and American biologists have reported an increase in biomass production in ecosystems colonised by non-native plant species. In the face of climate change, these and other changes to ecosystems are predicted to become more frequent, according to the researchers.


All over the world, plant and animal species are increasingly encroaching upon ecosystems where they don't belong as a result of human influence. This phenomenon is known as a biological invasion. Observational studies on biological invasions show that the invasion of non-native plant species can alter ecosystems. One important aspect of this is biomass production: compared to intact ecosystems, the productivity of ecosystems with non-native species is considerably higher. "In such purely observational studies however, it is not possible to differentiate between cause and effect," says Dr. Harald Auge from the Helmholtz Center for Environmental Research (UFZ). "The question is whether exotic plant species prefer to colonise more productive ecosystems, or whether increased productivity is a result of the invasion."