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SSS6.12 Soil organic matter under human pressure - from process understanding to national inventories |
| Convener: Axel Don | Co-Conveners: Jens Leifeld , Bas van Wesemael , Christopher Poeplau , Isabel Miralles Mellado |
Understanding the effects of land-management and land-use on soil organic carbon (SOC) and inorganic dynamics is pivotal for global change research. Soils are one of the largest carbon pools and a small change in SOC content could therefore substantially intensify, or mitigate, current atmospheric CO2 increase. However, changes in SOC stocks are mostly slow, originating from process originating from an imbalance between biomass litter input and decomposition. This balance is determine at different spatial scales ranging from mico-scale, where microbial mediated SOC turnover takes place, to field scale, where land management is performed, to global scale with climate change.
SOC stocks and dynamics are influenced by natural factors such as bedrock, soil type and climate variables and by anthropogenic drivers related to land-use and land-management. It is an ultimate scientific challenge to disentangle anthropogenic effects of land use and land management from natural driver’s impacts.
SOC consists of fractions with different ages resulting in different turnover times from years to millennia. Some of these fractions react to the present carbon cycle, whereas others are inherited under different conditions and reflect past land-use.
In this session, we welcome studies on SOC carbon dynamics using measurements of CO2 fluxes, inventories, lab studies or applications of models on the soil carbon dynamics in the context of land-use and land-management.
| Public information: |
Human impact on the soil system as a result of land-use and land-management has reached a level that the global carbon cycle is directly perturbed. Understanding the effects of land-management and land-use on soil organic carbon (SOC) dynamics is pivotal for global change research. Soils are one of the largest carbon pools and a small change in SOC content could therefore substantially intensify, or mitigate, current atmospheric CO2 increase. However, changes in SOC stocks are mostly slow, originating from process originating from an imbalance between biomass litter input and decomposition. This balance is determined at different spatial scales ranging from mico-scale, where microbial mediated SOC turnover takes place, to field scale, where land management is performed, to global scale with climate change. At the landscape scale soil erosion entrains lateral fluxes of C resulting in burial of C in colluviums and replacement of soil C on eroded hillslopes. These processes may induce a C sink at the global scale. Carbon models can help to bridge the gap between the different scales. SOC stocks and dynamics are influenced by natural factors such as bedrock, soil type and climate variables and by anthropogenic drivers related to land-use and land-management. It is an ultimate scientific challenge to disentangle anthropogenic effects of land use and land management from natural driver’s impacts. The human induced effect has to be reported under the United Nations Framework Convention on Climate Change (UNFCCC) within the national inventory reports (NIR) on annual carbon emissions from forest management (FM) and land use and land use change (LULUCF). In this session, we present studies on SOC carbon dynamics using measurements of CO2 fluxes, soil carbon inventories, lab and field studies or applications of models in the context of land-use and land-management and in relation to national GHG reporting. |