Terrestrial Antarctic ecosystems in the changing world: An overview

Abstract

Abstract:Although the Antarctic has avoided the worst effects of alien species, its future seems endangered due to increasing natural and man−made pressures. Rapid changes in three major environmental variables have occurred in the Antarctic region during the last decades. In the short term terrestrial biota are likely to benefit from reduced environmental stresses, but in the long run the colonization of the region by lower latitude species with greater competi− tive ability will become increasingly important and can lead to large−scale changes in biologi− cal composition and trophic complexity in some existing Antarctic terrestrial ecosystems. Moreover, the recent dynamic climate changes combined with human activities in the Antarc− tic region might modify the status of several alien species which have hitherto been consid− ered transient or persistent and could, therefore, become naturalized and threaten the native communities on a larger scale than today, or influence the status of naturalized species.

Pygoscelid penguins breeding distribution and population trends at Lions Rump rookery, King George Island

“…After the first reports by Stephens, one day censuses of breeding populations of penguins were made several times (Croxall and Kirkwood 1979;Jabłoński 1984;Ciaputa and Sierakowski 1999). In the South Shetlands intensive whaling exploitation took place in the early twenti− eth century (Chwedorzewska 2009). Intensive commercial fishing for fish and krill in the area began in the early 1970s (Everson and Goss 1991;Croxall and Nicol 2004) and continues up to the present day (Nicol et al 2012).…”

Biological invasions in terrestrial Antarctica: what is the current status and can we respond?

“…For instance, SCAR recommended that P. annua be eradicated from around the Polish Henryk Arctowski Station, Admiralty Bay, King George Island in the early 1990s (Smith 2011). However, although considerable efforts have been made to monitor and study the plants (Olech 1996(Olech , 1998(Olech , 2003Chwedorzewska 2008Chwedorzewska , 2009, no attempt at eradication has been reported (Olech and Chwedorzewska 2011).…”

Diaspores of the Introduced Species Poa annua L. in Soil Samples from King George Island (South Shetlands, Antarctica)

“…The number of alien species introduced temporarily in the Antarctic is still small (Lewis-Smith, 1996, Chwedorzewska, 2009. It is noteworthy that plant species introduced even in imported soil from site of origin did not persist longer than a couple of winter periods (Corte, 1961;Holdgate, 1964).…”

“…The most vital factor is the availability of liquid water (Kennedy, 1993). Botanical responses to climate amelioration are already visible in the maritime Antarctic in the rapid increase in density and extension of distribution of indigenous vascular plant species populations (Fowbert and Smith, 1994;Vera, 2011) and in the arrival of introduced species (Chwedorzewska, 2008(Chwedorzewska, , 2009Cuba-Diaz et al, 2012;Molina-Montenegro et al, 2012). The majority of documented introduced species in the Antarctic are considered humandependent immigrants (e.g.…”