Moss is turning Antarctica’s icy landscape green – Moss growth has “increased by 4 or 5 times” in the past five decades

By Zamira Rahim
20 May 2017 (CNN) – Antarctica is home to ice, penguins and — thanks to climate change — rapidly increasing levels of moss, scientists say. Moss banks, found across parts of the western Antarctic Peninsula, have grown dramatically over the past 50 years, according to a study published in the scientific journal Current Biology. Moss growth has “increased by 4 or 5 times” in the past five decades, according to Tom Roland, one of the co-authors of the report.

Higher temperatures and less ice are “likely open up more land for the moss ecosystems to expand into,” Roland said, leading to the “‘greening’ of the Peninsula.” “If you’d taken a photograph of these parts of the Peninsula 50 years ago it would have been a monochrome shot of ice,” Dominic Hodgson, another of the study‘s co-authors, told CNN. “Nothing but glaciers. “Today that photo would show extensive patches of green,” he noted. [more]

Moss is turning Antarctica’s icy landscape green

ABSTRACT: Recent climate change on the Antarctic Peninsula is well documented [1, 2, 3, 4, 5], with warming, alongside increases in precipitation, wind strength, and melt season length [1, 6, 7], driving environmental change [8, 9]. However, meteorological records mostly began in the 1950s, and paleoenvironmental datasets that provide a longer-term context to recent climate change are limited in number and often from single sites [7] and/or discontinuous in time [10, 11]. Here we use moss bank cores from a 600-km transect from Green Island (65.3°S) to Elephant Island (61.1°S) as paleoclimate archives sensitive to regional temperature change, moderated by water availability and surface microclimate [12, 13]. Mosses grow slowly, but cold temperatures minimize decomposition, facilitating multi-proxy analysis of preserved peat [14]. Carbon isotope discrimination (Δ13C) in cellulose indicates the favorability of conditions for photosynthesis [15]. Testate amoebae are representative heterotrophs in peatlands [16, 17, 18], so their populations are an indicator of microbial productivity [14]. Moss growth and mass accumulation rates represent the balance between growth and decomposition [19]. Analyzing these proxies in five cores at three sites over 150 years reveals increased biological activity over the past ca. 50 years, in response to climate change. We identified significant changepoints in all sites and proxies, suggesting fundamental and widespread changes in the terrestrial biosphere. The regional sensitivity of moss growth to past temperature rises suggests that terrestrial ecosystems will alter rapidly under future warming, leading to major changes in the biology and landscape of this iconic region—an Antarctic greening to parallel well-established observations in the Arctic [20].