Non-native species in Antarctic terrestrial environments: the impacts of climate change and human activity.

Abstract Antarctic terrestrial biodiversity is simple compared to other regions of the Earth, with many higher taxonomic groups not represented, due to the continent's isolation, the severe climatic conditions and the relative scarcity of suitable habitats. So far, Antarctic biodiversity has been little affected by nonnative species introductions, due to (i) the late arrival of humans on the continent (c.1820), (ii) the overall low intensity of human activity and (iii) the concentration of most of that activity around a limited number of research stations and tourist sites, such as exist on the Antarctic Peninsula. However, human activity is increasing, and Antarctica is increasingly vulnerable to the human-mediated importation of non-native species and the redistribution of indigenous Antarctic species. While the Antarctic Peninsula is one of the most rapidly warming regions on the planet, the Antarctic continent has, so far, experienced relatively little climatic change, but this is expected to change over the next century. Consequently, terrestrial communities are increasingly vulnerable, as climate change increases the risk of non-native species establishment and dispersal. This chapter describes non-native species in Antarctica that have already become established. Also described are the eradications that have been attempted and the practicality of minimizing microbial introductions. Finally, the chapter discusses recent policy developments relating to nonnative species and suggests that more needs to be done by the Antarctic Treaty Parties to implement biosecurity practices and eradicate existing non-native colonists, before fragile Antarctic communities are changed irreversibly.