Background
The authors write that the "annual temperatures on the Antarctic Peninsula, one of the most rapidly warming regions on Earth, have risen by up to 0.56°C per decade since the 1950s (Turner et al., 2009)." And they say that both "terrestrial and marine organisms have shown changes in populations and distributions over this time (Ducklow et al., 2007; Parnikoza et al., 2009), suggesting that the ecology of the Antarctic Peninsula is changing rapidly."

What was done
According to Royles et al., who studied this transformation of the northernmost part of the biggest and most prominent peninsula in Antarctica in some detail, they "developed a unique time series of peat moss growth and soil microbial activity from a 150-year-old moss bank at the southern limit of significant plant growth based on accumulation rates, cellulose ð¹³C, and fossil testate amoebae."

What was learned
The seven scientists, all hailing from the United Kingdom, demonstrated that "the rapid increase in moss growth and microbial activity observed since the late 1950s in the moss bank record is a consequence of warming temperatures and increased summer precipitation enabling higher metabolic rates and longer growing seasons." And they say that "these biological changes are unprecedented, at least over the post-industrial period (since AD 1850)," adding that "we can attribute the direct observations of increased biological activity in the late 20th century (Convey et al., 2009) to climate, based on direct and indirect long-term climatic baselines."

What it means
As the Little Ice Age gradually relinquished its death-promoting grip on some of the coldest parts of the world, new opportunities for life have gradually returned to places from which life had fled during the LIA's life-preventing tenure, with the Antarctic Peninsula being one of the most prominent of such locations.

References
Convey, P., Bindschadler, R.A., di Prisco, G., Fahrbach, E., Gutt, J., Hodgson, D.A., Mayewski, P., Summerhayes, C.P. and Turner, J. 2009. Antarctic climate change and the environment. Antarctic Science 21: 541-563.

Ducklow, H.W., Baker, K., Martinson, D.G., Quetin, L.B., Ross, R.M., Smith, R.C., Stammerjohn, S.E., Vernet, M. and Fraser, W. 2007. Marine pelagic ecosystems: the west Antarctic Peninsula. Philosophical Transactions of the Royal Society of London. B Biological Science 362: 67-94.

Parnikoza, I., Convey, P., Dykyy, I., Trokhymets, V., Milinevsky, G., Tyshenko, O., Inozemtseva, D. and Kozeretska, I. 2009. Current status of the Antarctic herb tundra formation in the Central Argentine Islands. Global Change Biology 15: 1685-1693.

Turner, J., Bindschadler, R., Convey, P., di Prisco, G., Fahrbach, E., Gutt, J., Hodgson, D., Mayewski, P. and Summerhayes, C. 2009. Antarctic Climate Change and the Environment. Scientific Committee on Antarctic Research, Cambridge, United Kingdom.