May 27, 2020
Journal Article

A moisture function of soil heterotrophic respiration that incorporates microscale processes

Benjamin Bond-Lamberty
Chongxuan Liu
Zhifeng Yan
Katherine Todd-Brown
Vanessa Bailey
Cong-Qiang Liu
SiLiang Li

Abstract

Soil heterotrophic respiration (HR) is an important source of soil-to-atmosphere CO2 flux, but its response to changes in soil water content (?) is poorly understood. Earth system models (ESMs) commonly use empirical moisture functions to describe the HR-? relationship, introducing significant uncertainty in predicting CO2 flux from soils. Generalized, mechanistic models that address this uncertainty are thus urgently needed. Here we derive, test, and calibrate a novel moisture function, fm, that encapsulates primary physicochemical processes controlling soil HR. We validated fm using simulation results and published experimental data, and established the quantitative relationships between parameters of fm and measurable soil properties, which enables fm to predict the HR-? relationships for different soils across spatial scales. The fm function generated comparable HR-? relationships with laboratory and field measurements. It may thus reduce uncertainty in predicting the response of soil organic carbon stocks to climate change compared with the empirical moisture functions currently used in ESMs.

Revised: May 27, 2020 | Published: July 2, 2018

Citation

Yan Z., B. Bond-Lamberty, K. Todd-Brown, V.L. Bailey, S. Li, C. Liu, and C. Liu. 2018. "A moisture function of soil heterotrophic respiration that incorporates microscale processes." Nature Communications 9, no. 1:Article No. 2562. PNNL-SA-126718. doi:10.1038/s41467-018-04971-6