A stochastic model for daily subsurface CO2 concentration and related soil respiration


Journal Article

Near-surface soil CO2 gas-phase concentration (C) and concomitant incident rainfall (Pi) and through-fall (Pt) depths were collected at different locations in a temperate pine forest every 30 min during the 2005 and 2006 growing seasons (and then averaged to the daily timescale). At the daily scale, C temporal variations were well described by a sequence of monotonically decreasing functions interrupted by large positive jumps induced by rainfall events. A stochastic model was developed to link rainfall statistics responsible for these jumps to near-surface C dynamics. The model accounted for the effect of daily rainfall variability, both in terms of timing and amount of water, and permitted an analytical derivation of the C probability density function (pdf) using the parameters of the rainfall pdf. Given the observed positive correlation between daily C and soil CO2 fluxes to the atmosphere (Fs), the effects of various rainfall regimes on the statistics of Fs can be deduced from the behavior of C under different climatic conditions. The predictions from this analytical model are consistent with flux measurements reported in manipulative experiments that varied rainfall amount and frequency. © 2008 Elsevier Ltd. All rights reserved.

Full Text

Duke Authors

Cited Authors

  • Daly, E; Oishi, AC; Porporato, A; Katul, GG

Published Date

  • July 1, 2008

Published In

Volume / Issue

  • 31 / 7

Start / End Page

  • 987 - 994

International Standard Serial Number (ISSN)

  • 0309-1708

Digital Object Identifier (DOI)

  • 10.1016/j.advwatres.2008.04.001

Citation Source

  • Scopus