Measuring and predicting the mobilisation of carbon from peat and its impacts on runoff and gas emissions.

by Stuart Andrew Rae

Institution: University of Manchester
Year: 2015
Record ID: 1399386
Full text PDF: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:247754


This work examines the chemical composition of peatland soils and their associated fluxes of organic carbon. This thesis has demonstrated through the long-term incubations of peat material that ex-situ greenhouse gas (GHG) production from peats is variable over time, despite constant conditions during the incubation period, suggesting that the uncertainties associated with ex-situ GHG measurements of peat may have often been underestimated. In addition, the in-situ GHG monitoring carried out in this research suggests the ability of O2 to penetrate into even the deepest regions of the peat profile, potentially providing a possible explanation for the temporal variability in GHG production.This work has also demonstrated how peatland restoration may potentially affect the mobilisation of carbon from peatland sites. The simulations of runoff derived from Sphagnum vegetation and areas bare peat show significantly different chemical compositions and behaviour when treated with iron flocculating agents, suggesting that the re-vegetation of upland peats to reduce GHG emissions may have the additional benefit of making the peat runoff easier to treat. However, the assessment of the restoration campaign carried out across a lowland peat mire suggests that the restoration of the site has introduced a significant variability into the hydrology of the restored areas of the bog, which may have triggered a change in the chemical composition of the bog and increased in-situ concentrations of GHGs within the peat. In addition, the utility of chemical analysis in the differentiation of spatially and temporarily different peats and prediction of their operational behaviour has been examined. This analysis has suggested that although certain analytical methods may be inappropriate for predicting future behaviour, they may prove useful as a means of monitoring peatland restoration.