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Quantifying Lateral Diffusion Error in Soil Carbon Dioxide Respiration Estimates using Numerical Modeling
Author(s) -
Creelman Chance,
Nickerson Nick,
Risk David
Publication year - 2013
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2012.0352
Subject(s) - thermal diffusivity , diffusion , soil science , environmental science , soil respiration , perturbation (astronomy) , carbon dioxide , respiration , atmospheric sciences , soil water , geology , physics , chemistry , thermodynamics , quantum mechanics , biology , botany , organic chemistry
A variety of chamber methodologies have been developed in an attempt to accurately measure the rate of soil CO 2 respiration. However, the degree to which these methods perturb and misread the soil signal is poorly understood. One source of error in particular is the introduction of lateral diffusion due to the disturbance of the steady‐state CO 2 concentrations. The addition of soil collars to the chamber system attempts to address this perturbation, but may induce additional errors from the increased disturbance. Using a numerical three‐dimensional (3D) soil‐atmosphere diffusion model, we have undertaken a comprehensive and comparative study of existing static and dynamic chambers. Specifically, we are examining the 3D diffusion errors associated with each method and opportunities for correction. The impacts of collar length and diffusion parameters on lateral diffusion around the instruments are quantified to provide insight into obtaining more accurate soil respiration estimates. Results suggest that while each method can approximate the true flux in low diffusivity environments, the associated errors can be large and vary substantially in their sensitivity to both method‐specific and environmental parameters. In some cases, factors such as collar length and soil diffusivity are coupled in their effects on accuracy.