We have investigated how the microbially-driven processes of carbon (C) mineralization(respiration) and nitrogen (N) mineralization/immobilization in a soil from the northern MaritimeAntarctic respond to differences in water availability (20% and 80% water-holding capacity) andtemperature (5°C and 15°C) in the presence and absence of different organic substrates (2 mg C as eitherglucose, glycine or tryptone soy broth (TSB) powder (a complex microbial growth medium)) in acontrolled laboratory experiment over 175 days. Soil respiration and N mineralization/immobilizationin the presence of a C-rich substrate (glucose) increased with increases in water and temperature. Thesefactors were influential individually and had an additive effect when applied together. For the N-richsubstrates (glycine and TSB), microbial responses to increased water or temperature alone were weak ornot significant, but these factors interacted to give significantly positive increases when applied together.These data indicate that under the expected changes in environmental conditions in the MaritimeAntarctic, where temperature and the availability of water and organic substrates will probably increase,soil microbial activity will lead to more rapid C and N cycling and have a positive feedback on thesebiogeochemical processes, particularly where or when these factors increase concurrently.
|Numero di pagine||8|
|Stato di pubblicazione||Published - 2014|
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