Tuesday, August 5, 2008 - 3:40 PM

COS 44-7: A spatial simulation of the carbon dynamics in Irish peat soils

Alan Gilmer, Dublin Institute of Technology

Background/Question/Methods

Effective management of the carbon balance of Irish peatland soils requires an understanding of the accumulation and efflux patterns on a spatial scale over defined landscape units. A model is presented that advances understanding of carbon peat soil dynamics and represents an appropriate decision support tool for peat soil management. The model embraces a mechanistic simulation approach. Soil carbon dynamics are described through the accumulation of parcels of organic matter in a one dimensional format. Each parcel of organic matter comprises a labile and a non-labile component. Parcel bulk density is used to determine the transition between aerobic and anaerobic zones within the soil profile.

Results/Conclusions

The model generates profiles of soil depth and mass with time, changes in the bulk density with depth and the efflux of CO2, CH4 and N2O. Sensitivity analysis was performed on the model. Model output for depth and mass was most sensitive to primary productivity. The parameter ranges used generate output profiles that show slowing in growth as they approach a steady state. Further growth then approximates a linear relationship with time. Spatial integration is reflected on a cellular basis. These outputs are consistent with available data for peat soils in the British Isles.