Monday, December 27, 2010

Socioeconomic legacy yields an invasion debt

"...Many of the most problematic alien species are not recent arrivals but were introduced several decades ago. Hence, current patterns of alien-species richness may better reflect historical rather than contemporary human activities, a phenomenon which might be called “invasion debt.” Here, we show that across 10 taxonomic groups (vascular plants, bryophytes, fungi, birds, mammals, reptiles, amphibians, fish, terrestrial insects, and aquatic invertebrates) in 28 European countries, current numbers of alien species established in the wild are indeed more closely related to indicators of socioeconomic activity from the year 1900 than to those from 2000, although the majority of species introductions occurred during the second half of the 20th century. The strength of the historical signal varies among taxonomic groups, with those possessing good capabilities for dispersal (birds, insects) more strongly associated with recent socioeconomic drivers. Nevertheless, our results suggest a considerable historical legacy for the majority of the taxa analyzed. The consequences of the current high levels of socioeconomic activity on the extent of biological invasions will thus probably not be completely realized until several decades into the future (PNAS)."

1 comment:

fnkykntr said...

Hi Shuang, was looking at this paper - it didn't really seem to say anything that isn't known already I thought? So, some invasives that were introduced some time ago are only now having a serious impact, and that this happened to wealthier countries (due to more trade pathways etc). Well, things do take time to establish, even invasives! I was a bit dissapointed they didn't consider as part of their discussion the differences between the situation 100 years ago and today, e.g. take into account current biosecurity policies, to make a statement about whether the pattern shown is likely to continue today or if there may be a shift in the relationship between socioeconomics and invasives.