Native distribution characteristics rather than functional traits explain preadaptation of invasive species to high-UV-B environments

Aim: Alien species successfully colonize new ranges if they encounter favourable environmental conditions there and possess traits that match new challenges. Climate matching approaches comparing native and exotic ranges mostly consider temperature and precipitation niches of alien species, but have largely ignored UV-B radiation. UV-B fundamentally differs between hemispheres, with much higher levels at southern than at northern latitudes. Consequently, UV-B might act at the global scale and present a so far neglected filter that species need to overcome when invading high-UV-B environments.

Location: We performed two multi-species common-garden experiments, conducted in the native European range (Germany) and the high-UV-B exotic range (New Zealand) to test for preadaptation to UV B.

Methods: We used 25 herbaceous species from open habitats, which we exposed in each range to three UV radiation treatments: (i) natural sunlight, (ii) exclusion of UV-B while allowing natural UV-A, ...