Quantifying thermal adaptation of soil microbial respiration

Quantifying the rate of thermal adaptation of soil microbial respiration is essential in determining potential for carbon cycle feedbacks under a warming climate. Uncertainty surrounding this topic stems in part from persistent methodological issues and difficulties isolating the interacting effects of changes in microbial community responses from changes in soil carbon availability. Here, we constructed a series of temperature response curves of microbial respiration (given unlimited substrate) using soils sampled from around New Zealand, including froma natural geothermal gradient, as a proxy for globalwarming. We estimated the temperature optima (Topt) andinflection point (Tinf) of each curve and found that adaptation of microbial respiration occurred at a rate of 0.29 degrees C +/- 0.04 1SE for Topt and 0.27 degrees C +/- 0.05 1SE for Tinf per degree of warming. Our results bolster previous findings indicating thermal adaptation is demonstrably offset from warming, and may help quantifying the potential for both limitation and acceleration of soil C losses depending on specific soil temperatures.

Automated summary

Quantifying the rate of thermal adaptation of soil microbial respiration is crucial for understanding the potential impact of carbon cycle feedbacks under a warming climate. This study found that microbial respiration exhibited an adaptation rate related to warming.