Dennis, P. G.8; Sparrow, A. D.3; Gregorich, E. G.4; Novis, P. M.5; Elberling, B.9; Greenfield, L. G.10; Hopkins, D. W.7
1 Geography, Department of Geosciences and Natural Resource Management, Faculty of Science, Københavns Universitet2 University of Stirling3 CSIRO Sustainable Ecosystems4 Agriculture and Agri-Food Canada, Central Experimental Farm5 Landcare Research6 University of Canterbury7 Heriot-Watt University8 University of Stirling9 Geography, Department of Geosciences and Natural Resource Management, Faculty of Science, Københavns Universitet10 University of Canterbury
The soils of the McMurdo Dry Valleys are exposed to extremely dry and cold conditions. Nevertheless, they contain active biological communities that contribute to the biogeochemical processes. We have used ester-linked fatty acid (ELFA) analysis to investigate the effects of additions of carbon and nitrogen in glucose and ammonium chloride, respectively, on the soil microbial community in a field experiment lasting three years in the Garwood Valley. In the control treatment, the total ELFA concentration was small by comparison with temperate soils, but very large when expressed relative to the soil organic carbon concentration, indicating efficient conversion of soil organic carbon into microbial biomass and rapid turnover of soil organic carbon. The ELFA concentrations increased significantly in response to carbon additions, indicating that carbon supply was the main constraint to microbial activity. The large ELFA concentrations relative to soil organic carbon and the increases in ELFA response to organic carbon addition are both interpreted as evidence for the soil microbial community containing organisms with efficient scavenging mechanisms for carbon. The diversity of the ELFA profiles declined in response to organic carbon addition, suggesting the responses were driven by a portion of the community increasing in dominance whilst others declined.
Antarctic Science, 2013, Vol 25, Issue 1, p. 55-61