Existing evidence and current understanding of changes in soil carbon stocks and soil greenhouse gas emissions as a result of land use change to bioenergy crop cultivation were reviewed. The main activities conducted were:
- Systematic review of direct land use change to bioenergy crops for soil carbon, soil processes, greenhouse gas balance and whole life-cycle carbon balance.
- Meta- analysis of direct land use change effects to bioenergy crops on soil carbon stocks and greenhouse gas balance.
- Consideration of wider ecosystems services in the context of direct land use change to bioenergy crops in the UK.
- A consideration of potential indirect impacts of land use change to bioenergy crops in the context of the UK.
- Significant knowledge gaps were identified around the impact of land use change to second generation bioenergy crops on soil carbon and GHG emissions. Where information did exist, it was primarily based on modelling work rather than empirical, measured data.
- Extensive data was available on land use change to first generation crops (e.g.wheat, oilseed rape, sugarbeet) but there was little empirical evidence on land use change to second generation bioenergy crops relevant to the UK (Miscanthus; short-rotation coppice Willow; and short-rotation forestry).
- There was a lack of published evidence on the impacts of land-use change to bioenergy on ecosystem services in the UK. From limited data, transitions from first-generation feedstocks to second-generation bioenergy crops were typically beneficial for ecosystem services whilst transitions from grasslands to second-generation bioenergy crops were typically less beneficial than transitions from cropland.