Prediction of vertical soil organic carbon profiles using soil properties and environmental tracer data at an untilled site

Wells, T.; Hancock, G. R.; Dever, C. G.; Murphy, D.

Title: Prediction of vertical soil organic carbon profiles using soil properties and environmental tracer data at an untilled site
Creator: Wells, T.; Hancock, G. R.; Dever, C. G.; Murphy, D.
Relation: Geoderma Vol. 170, Issue 15 January, p. 337-346
Publisher Link: http://dx.doi.org/10.1016/j.geoderma.2011.11.006
Publisher: Elsevier
Resource Type: journal article
Date: 2012
Description: Soil organic carbon (SOC) has considerable spatial and temporal variability both at the hillslope and catchment scale as well as down the soil profile. In recent years the distribution of SOC down the soil profile has become an area of interest in the understanding of the carbon sequestration potential of soils. Most studies however have concentrated on highly disturbed agricultural sites with little data available for untilled locations. In this study the vertical distribution of SOC is examined at a grassland site in the Young River area of Western Australia that has remained undisturbed by human activity for 50 years. Soil physical properties (texture, rock content) as well as the distribution of the environmental tracers ¹³⁷Cs and ²¹⁰Pb were assessed with the aim of better understanding the transport processes which produce the observed vertical distribution of SOC. While no consistent relationship was found between SOC and soil physical properties significant relationships were found between the distribution of SOC and the environmental tracers, ¹³⁷Cs and ²¹⁰Pb. Finite element simulations based on a diffusion/convection/decay model showed that the transport of ¹³⁷Cs and ²¹⁰Pb down the soil profile is likely to be driven by the same (primarily diffusive) processes. The same model used in conjunction with plant input and decay data generated from the RothC-26.3 soil carbon model revealed that transport of SOC down the soil profile, while also a diffusion process, was significantly slower indicating that different processes and/or pathways are involved in SOC transport at this site.
Subject: soil carbon; environmental tracers; finite element model; hydrology; geomorphology; FEM
Identifier: http://hdl.handle.net/1959.13/1336943
Identifier: uon:27735
Identifier: ISSN:0016-7061
Language: eng
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