Modelling soil organic carbon stocks in global change scenarios: a CarboSOIL application

[摘要] Global climate change, as a consequence of the increasing levels ofatmospheric CO₂ concentration, may significantly affect both soilorganic C storage and soil capacity for C sequestration. CarboSOIL is anempirical model based on regression techniques and developed as ageographical information system tool to predict soil organic carbon (SOC) contents at differentdepths. This model is a new component of the agro-ecological decision supportsystem for land evaluation MicroLEIS, which assists decision-makers in facingspecific agro-ecological problems, particularly in Mediterranean regions. Inthis study, the CarboSOIL model was used to study the effects of climate changeon SOC dynamics in a Mediterranean region (Andalusia, S Spain). Differentdownscaled climate models were applied based on BCCR-BCM2, CNRMCM3, andECHAM5 and driven by SRES scenarios (A1B, A2 and B2). Output data were linkedto spatial data sets (soil and land use) to quantify SOC stocks. The CarboSOILmodel has proved its ability to predict the short-, medium- and long-termtrends (2040s, 2070s and 2100s) of SOC dynamics and sequestration underprojected future scenarios of climate change. Results have shown an overall trendtowards decreasing of SOC stocks in the upper soil sections (0–25 cm and25–50 cm) for most soil types and land uses, but predicted SOC stocks tendto increase in the deeper soil section (0–75 cm). Soil types as Arenosols,Planosols and Solonchaks and land uses as "permanent crops" and "openspaces with little or no vegetation" would be severely affected by climatechange with large decreases of SOC stocks, in particular under themedium–high emission scenario A2 by 2100. The information developed in thisstudy might support decision-making in land management and climate adaptationstrategies in Mediterranean regions, and the methodology could be applied toother Mediterranean areas with available soil, land use and climate data.

[学科分类] 地球化学与岩石