1Present address: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
Climate change effects on organic matter decomposition rates in ecosystems from the Maritime Antarctic and Falkland Islands
Article first published online: 4 OCT 2007
Global Change Biology
Volume 13, Issue 12, pages 2642–2653, December 2007
How to Cite
BOKHORST, S., HUISKES, A., CONVEY, P. and AERTS, R. (2007), Climate change effects on organic matter decomposition rates in ecosystems from the Maritime Antarctic and Falkland Islands. Global Change Biology, 13: 2642–2653. doi: 10.1111/j.1365-2486.2007.01468.x
- Issue published online: 4 OCT 2007
- Article first published online: 4 OCT 2007
- Received 8 February 2007; revised version received 3 July 2007 and accepted 2 August 2007
- environmental change;
- microbial breakdown;
- soil respiration
Antarctic terrestrial ecosystems have poorly developed soils and currently experience one of the greatest rates of climate warming on the globe. We investigated the responsiveness of organic matter decomposition in Maritime Antarctic terrestrial ecosystems to climate change, using two study sites in the Antarctic Peninsula region (Anchorage Island, 67°S; Signy Island, 61°S), and contrasted the responses found with those at the cool temperate Falkland Islands (52°S). Our approach consisted of two complementary methods: (1) Laboratory measurements of decomposition at different temperatures (2, 6 and 10 °C) of plant material and soil organic matter from all three locations. (2) Field measurements at all three locations on the decomposition of soil organic matter, plant material and cellulose, both under natural conditions and under experimental warming (about 0.8 °C) achieved using open top chambers. Higher temperatures led to higher organic matter breakdown in the laboratory studies, indicating that decomposition in Maritime Antarctic terrestrial ecosystems is likely to increase with increasing soil temperatures. However, both laboratory and field studies showed that decomposition was more strongly influenced by local substratum characteristics (especially soil N availability) and plant functional type composition than by large-scale temperature differences. The very small responsiveness of organic matter decomposition in the field (experimental temperature increase < 1 °C) compared with the laboratory (experimental increases of 4 or 8 °C) shows that substantial warming is required before significant effects can be detected.