Comparative respirometry of peat decomposition on a latitudinal transect in the maritime Antarctic

The hypothesis that moss peat respiration in the maritime Antarctic was dependent more on edaphic conditions, substrate quality and microflora than latitude was broadly supported by studies on a 14° transect in 1980–81. Oxygen-uptake and CO2-release of samples from Polytrichum and Drepanocladus communities at five locations were compared by ANOVA. Regression analysis showed moisture and temperature to be prime regulators. A strong but unquantifiable influence of substrate quality was inferred. The influence of microbial biomass was blurred by variation. the absence in Polytrichum of significant multiple regressions of respiration with moisture and temperature implied stable respiration during a summer period of relatively invariable moisture, pH, Eh and potential substrate availability. Conversely, the occurrence of Drepanocladus in a broader range of moisture conditions yielded a significant regression. When extrapolated to estimate annual C-loss, this was similar to estimates for the 1975–77 seasons at Signy Island which was thereby shown to represent the maritime Antarctic