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How do soil organic carbon stocks change after cropland abandonment in Mediterranean humid mountain areas?
- Source :
- Science of the Total Environment, 566-567, 741-752. Elsevier
- Publication Year :
- 2016
-
Abstract
- The effects of land use changes on soil carbon stocks are a matter of concern stated in international policy agendas on the mitigation of greenhouse emissions. Afforestation is increasingly viewed as an environmental restorative land use change prescription and is considered one of the most efficient carbon sequestration strategies currently available. Given the large quantity of CO2 that soils release annually, it is important to understand disturbances in vegetation and soil resulting from land use changes. The main objective of this study is to assess the effects of land abandonment, land use change and afforestation practices on soil organic carbon (SOC) dynamics. For this aim, five different land covers (bare soil, permanent pastureland, secondary succession, Pinus sylvestris (PS) and Pinus nigra (PN) afforestation), in the Central Spanish Pyrenees, were analysed. SOC dynamics have been studied in the bulk soil, and in the fractions separated according to two methodologies: (i) aggregate size distribution, and (ii) density fractionation, and rates of carbon mineralization have been determined by measuring CO2 evolution using an automated respirometer. The results showed that: (i) SOC contents were higher in the PN sites in the topsoil (10 cm), (ii) when all the profiles were considered no significant differences were observed between pastureland and PN, (iii) SOC accumulation under secondary succession is a slow process, and (iv) pastureland should also be considered due to the relative importance in SOC stocks. The first step of SOC stabilization after afforestation is the formation of macro-aggregates promoted by large inputs of SOC, with a high contribution of labile organic matter. However, our respiration experiments did not show evidence of SOC stabilization. SOC mineralization was higher in the top layers and values decreased with depth. These results gain insights into which type of land management is most appropriate after land abandonment for SOC.
- Subjects :
- Topsoil
Environmental Engineering
Secondary succession
010504 meteorology & atmospheric sciences
Land use
Land management
Forestry
Soil science
04 agricultural and veterinary sciences
Soil carbon
Carbon sequestration
01 natural sciences
Pollution
040103 agronomy & agriculture
0401 agriculture, forestry, and fisheries
Environmental Chemistry
Environmental science
Afforestation
Land use, land-use change and forestry
Waste Management and Disposal
0105 earth and related environmental sciences
Subjects
Details
- Language :
- English
- ISSN :
- 00489697
- Database :
- OpenAIRE
- Journal :
- Science of the Total Environment
- Accession number :
- edsair.doi.dedup.....2ac43fd8419bf908ed150b1467d3d084