Warming impacts on potential germination of non-native plants on the Antarctic Peninsula

The
Antarctic Peninsula is under pressure from non-native plants and this risk is
expected to increase under climate warming. Establishment and subsequent range expansion
of non-native plants depend in part on germination ability under Antarctic
conditions, but quantifying these processes has yet to receive detailed
research attention. Here we show through viability testing under simulated field-based
soil surface conditions, that sixteen species, including grasses, herbs, rushes
and a succulent, germinated under current Antarctic summer conditions and thrived
under warming conditions. Soil surface degree day sum requirements for
germination of those sixteen species are present as far south as 72° S. Our experimental
approach shows that, both in terms of the number of species and of geographical
range, the establishment potential of non-native species is far greater than currently
suggested by species distribution modelling approaches with important implications
for risk assessment of non-native species along the Antarctic Peninsula.