Temperature dependence of decomposition of soil organic matter and thermalaccli, The
presentationposted on 07.08.2014, 00:00 by Jennifer Bell
Soil organic matter represents one the largest pools of stored carbon on the planet and is a major contributor to terrestrial CO2 fluxes. Decomposition of soil organic matter adds carbon dioxide to the atmosphere, which could lead to even higher temperatures, creating a positive feedback, lessening the carbon storage rate and accelerating climate change. However, this positive feedback may be decreased if soil microorganisms can acclimate, or down-regulate their metabolism, in response to elevated temperatures. To investigate this phenomenon, we set up a short-term laboratory incubation in which soils from a forest ecosystem were incubated at three different temperatures. In half the samples, dextrose was added to alleviate substrate limitation. Respiration and microbial biomass measurements were taken throughout the month. After a month, the soils were split up and moved to the other temperatures and respiration measurements were taken after six hours. We found that the soil had increased rates of decomposition with increasing temperature and that the microorganism did experience acclimation acclimate suggesting that the positive feedback of increased decomposition rates will not be lessened.