When alien plants integrate into an existing ecosystem and successfully spread there, in rare cases this can contribute to the increased uniqueness of the regional flora. However, much more often this process – known as "naturalization" – leads to a homogenization of regional floras and thus to a net loss of global floristic uniqueness. Especially "super-invaders", which are highly effective at colonizing new territory and displacing native species, are causing the flora in even distant regions with clear geographic separation to become increasingly similar. These are the findings of an international research team led by biologists from Konstanz that were published in the journal Nature Communications.
Global Databases Used for Study
In their recent study, the researchers used global databases to make the first comparison of the composition of 658 regional floras from nearly all parts of the world. In addition, they investigated the influence of biogeographical and anthropogenic (i.e., man-made) factors on the increasing homogenization of regional floras. To assess the floristic uniqueness of individual regions, they took into account both the number of plant species that a region shares or does not share with other regions and the degree to which plant species are related to each other. In doing so, they also included regional evolutionary histories in their analysis.
An important role in the spread of alien plants and the loss of uniqueness of regional floras is played by various biogeographic factors. These factors include the geographic distance between the regions under consideration and their “climatic distance” from each other, according to the study. "The more similar two regions are in terms of climate, the more likely it is that a plant from one region will succeed in establishing itself as a naturalized species in the other region, once geographic barriers have been crossed. In a sense, plants from a region with short climatic distance to their new habitat are 'climatically pre-adapted'", Dr Qiang Yang, the lead author of the study, explains the effect.
Read more at University of Konstanz
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