An evaluation of Scottish woodland grant schemes using site suitability modelling. (January 2019) - Thomas, Haydn J.D.
Highlights: We evaluate woodland expansion since 1989 using site suitability modelling. Local climate will constrain establishment or growth for unsuitable species. 88–97% of new woodland is located on suitable sites; this has improved over time. Higher suitability is concurrent with increased emphasis on ecological modelling. Forester use of modelling remains low; greater emphasis is placed on experience. Abstract: Woodland expansion is a key component of Scottish land use policy, with targets to increase woodland cover from 18% towards 25% of land area by 2050. However, to date there has been little assessment of whether forestry policy is achieving its objectives. Here, we present an evaluation of woodland grant schemes based on site suitability modelling for the Lochaber Forest District in northwest Scotland. We perform a spatial analysis of woodland creation between 1988 and 2014 using site suitability scores generated through the Forest Research Ecological Site Classification (ESC) methodology. We further conduct in-depth interviews with fourteen stakeholders within the grant-scheme application process to explore the influence of ecological suitability on woodland planning. We find that 92% of woodlands are suited to current climate conditions, and that suitability has improved under the latest grant scheme. This is concurrent with an increased emphasis on suitability modelling in decision-making, though could be explained by cultural changes or a more rigorous approvals process. We find that ecological variables are used to inform woodland location and species selection, but that woodland type is more commonly determined by grant structure. Finally, we discuss other potential limits to grant scheme success, including climate change, edaphic variables and woodland management.