Bioenergy crops have attracted increasing interest over the last two decades as their potential to 1) improve national energy security, 2) substitute finite fuels with renewable alternatives, 3) reduce carbon (C) intensity of energy generation, and 4) remove CO2 from the atmosphere and sequester it in soils. In light of climate change predominantly caused by rising atmospheric greenhouse gas concentrations, the potential importance and value of bioenergy cannot be underestimated. This research used data from a single site in Lincolnshire, UK, in combination with new experimental techniques to examine the C dynamics associated with Miscantus x giganteus. The net C budgets were examined using long term eddy-covariance data alongside measurements of C stocks within the soil and litter layer. Results indicated that using a cradle-to-grave lifecycle analysis, and based on the productivity of this site, Miscanthus as an energy feedstock was marginally better than coal but more C intensive than natural gas. Further, soil C stocks were not seen to change significantly over the first 7 years of cropping. Consequently, a combination of soil fractionation and in combination with natural abundance stable C isotope techniques allowed rates of soil C gain or loss to be estimated over time. Soil C was observed to accumulate at fast rates in stable fractions, those that relate to model pools with turnover times well beyond the lifetime of a Miscanthus plantation – a result not predicted by model simulations performed with the systems models ECOSSE and DayCent. A review of six models parameterised for Miscanthus showed a number of factors that contribute to model uncertainty. The results from this thesis are a crucial first step to helping to define model parameters and improve model performance, and therefore to accurately predict the impacts of Miscanthus on C sequestration in a given location for given environmental conditions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:668981 |
| Date | January 2015 |
| Creators | Robertson, Andrew D. |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=227603 |
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