While the sheer number of plant species in Europe is increasing as a result of introduction of non-native species, the flora as a whole is becoming less and less diverse, scientists from the EU project DAISIE (Delivering Alien Invasive Species Inventories for Europe) reported recently in Proceedings of the National Academy of Sciences (USA).
The researchers were able to demonstrate that biodiversity is increasing in all regions of Europe due to high numbers of alien species. But at the same time the plant communities of the regions are becoming increasingly more homogenous because alien species are distributed relatively consistently over the continent. The remarkable thing is that it is not only the diversity between plant communities that is decreasing (taxonomic homogenisation), but also the phylogenetic diversity, a news summary of the research in Science Daily observes in a Dec. 11 feature story.
“The genealogical tree of the plant species occurring in Europe has got more twigs, but these only sprout from a few large branches,” Science Daily explains.
The effectiveness of alien plant species to colonize and outcompete native species in human-disturbed habitats is widely believed to have corresponding negative impacts on butterfly diversity, even while some butterfly species whose larvae are generalist feeders or are adapted to now-commonplace invasives may flourish.
Read the full Science Daily story here: 2009 Science Daily 11 Dec Europe flora diminished