Soil organic carbon stocks in Flemish grasslands: how accurate are they?

Abstract

Articles 3AE3 and 3AE4 of the Kyoto protocol provide Annex I countries the possibility to reduce greenhouse gas emissions through the sequestration of carbon (C) in their terrestrial ecosystems. For such accounting, the 1990 flux is needed and, therefore, a correct knowledge of the baseline (1990) C stocks is necessary. In addition, a correct methodology should be used to investigate the capacity of ecosystems to sequester C through changes in land use or management by the end of the first commitment period (2008)(2009)(2010)(2011)(2012). At national and regional scales, formulation of baseline C stocks in terrestrial ecosystems is difficult and uncertain. Differences in method of analysis, sampling depth of soil, lack of sufficient C data and the necessity to extrapolate C data to total soil organic C stocks, provide problems when comparing databases with each other. In this study, three extrapolation models were compared with the classical layer-based method to determine the model with the best fit. The model with the best predictions, in relation to the classical layer-based model, uses recent soil C profiles for estimating the parameter k, which represents the decrease in the proportion of soil organic C with depth, and for extrapolating the C data available for 1990 and 2000 to a depth of 1 m. The other two models gave large underestimates.

Carbon and nitrogen distribution pattern in soil profile cultivated with Eucalyptus

“…These values are similar to the values obtained by the mathematical method, as well as to the values found by Mestdagh et al 2004 Considering the graphical method, between different soil uses the decay rate (k) of the TOC content varied by 0.0643% and 0.0654 g cm -3 and, for the TN, the variation of the k of the content was by 0.0997% and 0.1129 g cm -3 . These values of k are similar to those reported by Mestdagh et al (2004) in different soils, confirming that the value of the parameter k is important when we intend to make extrapolations of the carbon content in depth.…”

“…to Mestdagh et al (2004), express a rapid decrease in the organic carbon content of the soil from the surface to the subsurface layers. The surface horizons have high contents, which rapidly decrease in the deepest horizons.…”

Soil organic carbon contents of agricultural land in the Netherlands between 1984 and 2004

“…Exchange of land between arable farms and grassland-based dairy farms has increase during the last decades. Decreasing SOC content in grassland soils in Belgium was also related to changes in land use (Mestdagh et al, 2004(Mestdagh et al, , 2006.…”

Soil organic carbon stocks in verges and urban areas of Flanders, Belgium

“…Bulk densities for the different depths were used according to Mestdagh et al (2004). For the depth of 60-100 cm, the bulk density for the depth of 30-60 cm was used.…”