Comparative Microbiology of Moss-Peat Decomposition on the Scotia Arc and Antarctic Peninsula

Summary

The hypothesis that microbial activity and abundance in Antarctic peat are regulated more by substrate and moisture than directly by temperature or latitude was broadly supported throughout a 51° to 68° S transect. A consistent difference between respiration in Polytrichum- and Drepanocladus-peat supported the substrate-dependence notion. A correlation between respiration and a broad mixture range in Drepanocladus was precluded by a narrower range in Polytrichum. The absence of correlation between O₂ uptake and CO₂ release suggested anaerobic CO₂-production in wet conditions. Corrections using Q₁₀ coefficients indicated limited temperature responses. Moisture-dependent decomposition gave significant loss in tensile strength (LTS) of cotton strips nearer the surface in wet sites than dry ones. Ground isolation partly accounted for LTS at high latitude. Strip discoloration suggested cellulose decomposition by chromo-gens found at the sites. Viable counts did not correlate with respiration. Counts consistently different between fellfield and moss communities reflected substrate characteristics.