How does temperature affect forest "fungus breath"? Diurnal non-exponential temperature-respiration relationship, and possible longer-term acclimation in fungal sporocarps

Abstract

Fungal respiration contributes substantially to ecosystem respiration, yet its field temperature response is poorly characterized. I hypothesized that at diurnal time scales, temperature-respiration relationships would be better described by unimodal than exponential models, and at longer time scales both Q₁₀ and mass-specific respiration at 10 °C (R_ms10) would show signs of acclimation. I measured respiration on intact sporocarps over the course of several days, and modeled temperature-respiration relationships using exponential and unimodal Gaussian functions. Unimodal models provided a better fit than exponential models. R_ms10 and Q₁₀ also declined with increasing temperature, consistent with longerterm temperature acclimation. There was some evidence of diurnal hysteresis. When exponential models were appropriate, Q₁₀ values averaged ∼3.5, and R_ms10 averaged 0.02 µmol CO₂ g^-1 sec^-1. The observed high mass-specific respiration rates, peaked temperature responses, decline in R_ms10 and Q₁₀ with increasing temperature, and hysteresis could contribute to observed non-exponential and hysteretic patterns in soil and ecosystem respiration.

Citation

Lilleskov, Erik A. 2017. How does temperature affect forest "fungus breath"? Diurnal non-exponential temperature-respiration relationship, and possible longer-term acclimation in fungal sporocarps. Fungal Ecology. 27: 24-35. https://doi.org/10.1016/j.funeco.2017.02.001.