Modeling the production, decomposition, and transport of dissolved organic carbon in boreal soils

Soil Science
By: , and 

Links

Abstract

The movement of dissolved organic carbon (DOC) through boreal ecosystems has drawn increased attention because of its potential impact on the feedback of OC stocks to global environmental change in this region. Few models of boreal DOC exist. Here we present a one-dimensional model with simultaneous production, decomposition, sorption/desorption, and transport of DOC to describe the behavior of DOC in the OC layers above the mineral soils. The field-observed concentration profiles of DOC in two moderately well-drained black spruce forest sites (one with permafrost and one without permafrost), coupled with hourly measured soil temperature and moisture, were used to inversely estimate the unknown parameters associated with the sorption/desorption kinetics using a global optimization strategy. The model, along with the estimated parameters, reasonably reproduces the concentration profiles of DOC and highlights some important potential controls over DOC production and cycling in boreal settings. The values of estimated parameters suggest that humic OC has a larger potential production capacity for DOC than fine OC, and most of the DOC produced from fine OC was associated with instantaneous sorption/desorption whereas most of the DOC produced from humic OC was associated with time-dependent sorption/desorption. The simulated DOC efflux at the bottom of soil OC layers was highly dependent on the component and structure of the OC layers. The DOC efflux was controlled by advection at the site with no humic OC and moist conditions and controlled by diffusion at the site with the presence of humic OC and dry conditions.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Modeling the production, decomposition, and transport of dissolved organic carbon in boreal soils
Series title Soil Science
DOI 10.1097/SS.0b013e3181e0559a
Volume 175
Issue 5
Year Published 2010
Language English
Publisher Lippincott Williams & Wilkins, Inc.
Contributing office(s) Toxic Substances Hydrology Program, National Research Program - Central Branch
Description 10 p.
First page 223
Last page 232
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page