Little evidence for respiratory acclimation by microbial communities to short‐term shifts in temperature in red pine (Pinus resinosa) litter

Forest litter is a large reservoir of organic compounds that adds CO 2 to the atmospheric carbon pool when it decomposes. Predicting CO 2 efflux from litter decomposition is difficult because litter can undergo significant diurnal and day-to-day shifts in temperature. Moreover, the relationship between temperature and respiration may change if the decomposer microorganisms acclimate to short-term temperature changes. Therefore, we studied the relationship between temperature and respiration by litter decomposer microorganisms in a Pinus resinosa (Ait.) system and tested the hypothesis that their respiration acclimates to temperature. We found only limited evidence for acclimation following 6 °C shifts for 7 days. This suggests that increase in respiratory CO 2 loss associated with increased temperature would not be greatly ameliorated by physiological acclimation for periods of up to a week.