Climate warming in polar regions is associated with thawing of permafrost, resulting in significant changes in soil hydrology, biogeochemical cycling, and in the activity and composition of soil communities. While ongoing, directional climate warming can elicit such responses over decadal time scales, their manifestation typically occurs as discrete thawing pulses. Indeed, in the McMurdo Dry Valleys of Antarctica abrupt changes in community structure and biogeochemical cycling in terrestrial and aquatic ecosystems following a summer warming event (Jan.
Increases in soil temperature and moisture may change the bioavailability of essential elements by altering solubility and diffusion rates in soils, or by changing the amounts of organic compounds. Long-term experiments in the Bonney, Hoare and Fryxell basins have been established with 3 treatments: 1) increased moisture, 2) soil warming (ITEX chambers), and 3) soil warming + increased moisture. The identification and abundance of soil biota are reported.