Visions for woodland expansion in 21st Century Scotland: alternative governance strategies and ecosystem service implications

Abstract

In order to tackle global challenges including climate change, biodiversity and habitat loss, deforestation and forest degradation, land system research needs to support decision making which helps to develop sustainable land use systems. In a Scottish context woodland expansion and multi-functionality in terms of ecosystem service (ES) provision are core aims of land use policy. However, there are conflicting objectives between stakeholders and research has struggled to quantify the synergies and trade-offs between these. There is a lack of understanding in terms of how to achieve ES multi-functionality, as well as considerable uncertainty with regards to the continuation of public support for different land uses after Brexit. This thesis aimed to understand the synergies and trade-offs between ES generated by woodland expansion under alternative stakeholder ‘visions’ – or ‘positive descriptions of ideal futures.’ Through exploring how these visions might be met, it also examined how governance might influence woodland expansion and ES provision. An interdisciplinary approach was adopted, combining evidence synthesis, stakeholder engagement, and agent-based modelling (ABM) to explore the effect of alternative stakeholder visions for woodland expansion on ES provision. In Chapter 2, a systematic review of evidence for the effect of woodland expansion on biodiversity and ecosystem services in a UK context found that currently the largest body of evidence exists for the effects of conifer plantations, and public benefits such as carbon sequestration and flood regulation. Evidence gaps need to be filled in relation to a broader consideration of taxa and metrics for biodiversity, natural regeneration of native woodland, and effects on cultural and provisioning ES. Chapter 3 presents a mixed-method approach combining document analysis, a stakeholder workshop and semi-structured interviews, resulting in five distinct ‘visions’ for how woodland expansion might ideally take place. These illustrated a great deal of common ground between high-level stakeholders, but also important distinctions in terms of overall objectives, priority ES, and governance mechanisms with which visions might be achieved. In chapters 4 and 5, an established ABM framework was adapted to describe a new model, CRAFTY-Scotland. The elicited visions were represented within the model, in order to explore the ES implications and likelihood of meeting Scottish government targets for woodland expansion. Findings suggest that ABM offers a useful method for exploring normative visions, taking into account multiple ES and quantifying trade-offs between non-economic values. The results suggest that there could be largely positive effects of woodland expansion on ecosystem services, across visions. Trade-offs are quantified relating to declines in livestock and floral species diversity. However, all ecosystem services results are strongly dependent on the current data, knowledge, and modelling choices. Willingness of traditional and sporting estate managers to diversify has a strong influence on whether or not woodland cover targets are met. Key barriers to achieving targets appear to be the continued dominance of marginal agriculture and single-use management in the Highlands. Of the governance mechanisms represented within the model, the most successful include targeted annualised incentives for woodlands, diversified land management, and increased financial, human and social resources for local communities. Together, the findings suggest that more significant changes may be required to meet targets for woodland expansion, particularly in relation to highly valued ‘traditional’ Scottish landscapes. Any such changes should be debated at regional levels in participatory applications. Modelling approaches of this kind, combining spatially explicit data together with processes and governance of the land use system, are currently under-utilised and offer valuable decision support tools if built upon further. Given the urgent need to move towards sustainable land use in the face of multiple challenges, linking societal visions to models in research approaches which engage society with science and encourage futures thinking have great potential.