Europe's Flora Is Becoming Impoverished

With increasing species richness, due to more plant introductions than extinctions, plant communities of many European regions are becoming more homogeneous. The same species are occurring more frequently, whereas rare species are becoming extinct.

It is not only the biological communities that are becoming increasingly similar, but also the phylogenetic relations between regions. These processes have led to a loss of uniqueness among European floras, scientists from the DAISIE research project have published their findings in the current online edition of the scientific journal Proceedings of the National Academy of Sciences of the USA (PNAS).

Phylogenetic diversity reflects the evolutionary history of a community and therefore also its genetic diversity, which can also be an expression of its functional diversity. A phylogenetic tree with high diversity can be imagined as a genealogical tree with a protruding crown, with many strong branches (distantly related species) and numerous twigs (many species). A high phylogenetic and taxonomic diversity (many tree species that look different), presents a wealth of information and ability, making it possible for biological communities to react to environmental changes, like those arising for example from the current global climate change (e.g. climate or land use change). If one finds many very similar looking trees, then one assumes that the flexibility of the communities is no longer as high to be able to react positively to these changes. Put simply: 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