The Elum Project: A Network of UK Sites to Understand Land-Use Transitions to Bioenergy and Their Implications for Greenhouse Gas Balance and Carbon Cycling

Friday, 19 December 2014
Zoe M Harris1, Giorgio Alberti2, Emily Bottoms3, Rebecca Rowe3, Kim Parmar3, Rachel Marshall3, Dafydd Elias3, Pete Smith4, Marta Dondini4, Mark Pogson5, Mark Richards4, Jon Finch6, Phil Ineson7, Ben Keane7, Mike Perks8, Matthew Wilkinson8, Sirwan Yamulki8, Iain Donnison9, Kerrie Farrar9, Alice Massey9, Jon McCalmont9, Julia Drewer10, Saran Sohi11, Niall McNamara3 and Gail Taylor1, (1)University of Southampton, Southampton, SO14, United Kingdom, (2)University of Udine, Udine, Italy, (3)Centre for Ecology & Hydrology, Lancaster, United Kingdom, (4)University of Aberdeen, Aberdeen, United Kingdom, (5)University of Bolton, Bolton, United Kingdom, (6)Centre for Ecology & Hydrology, Wallingford, United Kingdom, (7)University of York, York, United Kingdom, (8)Forest Research, Centre for Sustainable Forestry & Climate Change, Alice Holt, United Kingdom, (9)Aberystwyth University, Aberystwyth, United Kingdom, (10)Centre for Ecology & Hydrology, Edinburgh, United Kingdom, (11)University of Edinburgh, Edinburgh, United Kingdom
Rising anthropogenic greenhouse gas (GHG) emissions coupled with an increasing need to address energy security are resulting in the development of cleaner, more sustainable alternatives to traditional fossil fuel sources. Bioenergy crops have been proposed to be able to mitigate the effects of climate change as well as provide increased energy security. The aim of this project is to assess the impact of land conversion to second generation non-food bioenergy crops on GHG balance for several land use transitions, including from arable, grassland and forest.

A network of 6 sites was established across the UK to assess the processes underpinning GHG balance and to provide input data to a model being used to assess the sustainability of different land use transitions. Monthly analysis of soil GHGs shows that carbon dioxide contributes most to the global warming potential of these bioenergy crops, irrespective of transition. Nitrous oxide emissions were low for all crops except arable cropping and methane emissions were very low for all sites. Nearly all sites have shown a significant decrease in CO2 flux from the control land use.

Eddy flux approaches, coupled with soil assessments show that for the transition from grassland to SRC willow there is a significant reduction in GHG emissions from soil and a negative net ecosystem exchange due to increased GPP and ecosystem respiration. These results suggest for this land use transition to bioenergy in a UK specific context, there may be a net benefit for ecosystem GHG exchange of transition to bioenergy

Finally we are developing a meta-modelling tool to allow land use managers to make location-specific, informed decisions about land use change to bioenergy.

This work is based on the Ecosystem Land Use Modelling & Soil Carbon GHG Flux Trial (ELUM) project, which was commissioned and funded by the Energy Technologies Institute (ETI). This project is co-ordinated by the Centre for Ecology & Hydrology (www.elum.ac.uk).