Over the past 50 years, portions of Antarctica and thesub-Antarctic islands have experienced some of the mostrapid increases in mean air temperatures on Earth. Forexample, recent data released by NASA have shown thatmean annual air temperatures over the Western AntarcticIce Sheet (WAIS) have already increased by roughly 1 Cand more than 2 C in the maritime Antarctic (e.g. Turneret al. 2005). Over the same period, introductions of non-indigenous species have also continued to increase partic-ularly in the sub-Antarctic islands (Frenot et al. 2005).While ongoing debate, often politically motivated, con-tinues to dominate discussion of climate change and itsimpacts, it is virtually certain that temperature increasesand species’ introductions will intensify and continue toinfluence Antarctic terrestrial ecosystems over the next50 years. Other human activities such as increasing num-bers of tourists and scientists will affect the present ter-restrial systems as well as those newly revealed as a resultof glacial melt. Collectively, these changes will influenceAntarctica’s biodiversity and ecosystem functioning aswell as the corresponding feedbacks to glaciers, freshwatersystems and the atmosphere. Thus, it is urgent that wedevelop a strong knowledge base for Antarctic terrestrialecosystems and use this to identify ecosystem change(NAS 2011).In order to advance our current state of knowledge, theScientific Committee for Antarctic Research (SCAR),through its life sciences programme Evolution and Biodi-versity in the Antarctic (EBA, http://www.eba.aq), hasencouraged multidisciplinary and multinational researchefforts. As part of this initiative, a special session on GlobalTipping Points, ‘‘Global Change and Antarctic TerrestrialBiodiversity’’, was convened at the 2010 SCAR Open Sci-ence Conference held in Buenos Aires (August 3–6, 2010).This special issue of Polar Biology and the articles thatfollow were based on this special session and were solic-ited to cover a range of topics, viewpoints and contributingcountries. We have assembled eight such manuscripts thatcover microbiological, botanical and zoological compo-nents as well as representing studies from continental,peninsular and sub-Antarctic island locations. This specialissue also provides a useful complement to a previousspecial issue of Polar Biology devoted to polar marine andfreshwater ecosystems (Agusti´ et al. 2010).The lead article by Convey (2011, this special issue)provides an overview of the Antarctic terrestrial environ-ment and its biodiversity. It then examines the range ofenvironmental changes as well as direct and indirect humanactivities that are likely to impact on this unique environ-ment. The final section is future-focused, outlining researchneeds as well as the research programmes and initiatives,past and present, which aim to address these issues. It endswith a plea for the urgent need to plan and properly fund, atnational and international levels, appropriate monitoring,manipulations and modelling approaches across the rangeof terrestrial environments found within the Antarctic(Wall et al. 2011).Green et al. (2011, this special issue) provide a detailedperspective on the consequences of increased temperaturesfor Antarctica’s vegetation. Using regression analyses