Life Cycle Assessment Based Modelling of Afforestation for Timber Production in Wales Incorporating Environmental Burdens and Ecosystem Services Impacts.

Abstract

Forestry in Wales is widely recognised in policy and academic discourse for its potential to deliver climate change mitigation, timber supply, and economic objectives alongside a range of ecosystem services, but outcomes vary depending on where forests are established, how they are managed, and what products they eventually produce. Life Cycle Assessment (LCA) traces industrial processes through supply chains, while ecosystem service assessments (ESA) capture ecological functions that support human wellbeing. Their differing scopes and system boundaries mean neither provides a complete picture of productive forestry on its own. This thesis develops a spatially explicit, attributional LCA-based framework to couple ecosystem service (ES) model outcomes with life cycle impact assessment of forest creation, management, and harvesting over a full rotation. The aim of the ES integrated LCA (ESLCA) is to inform afforestation and land use policy in Wales by identifying spatially heterogeneous trade-offs and synergies between timber production, ecosystem service provision, and the environmental burdens associated with forestry operations.

Biophysical flows: nutrient export, water regulation, and soil erosion, were modelled in InVEST to capture the impacts of afforestation on ecosystem services at the hectare scale across Wales. In parallel, inventories for forest establishment, management, and processing were analysed in SimaPro using EcoInvent datasets to quantify environmental burdens through emissions and resource use per m3 of timber, and per ha of forestry. Outputs from both strands were aligned as midpoints and aggregated into higher-level endpoints representing areas of protection for water supply, nutrient retention, and soil regulation. While not a full LCA damage characterisation, this midpoint–endpoint structuring provided a practical bridge: translating land use as an inventory flow and detailed ecosystem service outputs into categories compatible with LCA. A handprint–footprint index was developed to combine ecosystem service provision per hectare with LCA burdens per m3, positioning sites along a common scale of relative efficiency.

Results show that afforestation generally reduces nutrient export and improves erosion control, while decreasing quickflow but enhancing baseflow and aquifer recharge. Outcomes differed significantly by prior land use for some ecosystem services. The greatest environmental burdens were associated with ground preparation and planting. Lack of normalisation and weighting sets, and data on ecological limits, makes comparing environmental burdens and ecosystem service benefits difficult, but the combined approach can still be used to test relative ecosystem service impacts, timber yield, and environmental performance across Wales.

Functional unit choice strongly shaped interpretation. Per-hectare results characterise ecological performance well, but the perspective limits the capacity to meaningfully relate burdens and benefits to a unit of product as it enters a supply chain, while per m3 results risked distortion through productivity-linked inflation and deflation. LCA revealed that high-yield sites carry lower burdens per m3 but higher burdens per ha, while ecosystem service outcomes remain most meaningful when assessed per ha. The handprint–footprint index highlighted strong regional contrasts in trade-offs: productive lowlands exhibited high yield and efficient timber production, agricultural landscapes often delivered both ecosystem service gains and timber, while upland regions such as the Cambrian Mountains and Brecon Beacons scored lower. The South Wales Valleys showed a patchwork reflecting local variability in prior land use and in site productivity.

Two central research questions guided the work: (1) Where in Wales is afforestation best suited to balance timber production with ecosystem service provision? and (2) Can ecosystem service modelling and LCA be combined to provide such an answer? The thesis demonstrates that spatially explicit ESLCA can identify opportunities where forestry delivers multiple objectives at the least environmental cost, while clarifying the gaps that remain. Fully aligning ESA with LCA would require mapping demand for ecosystem services, developing spatially specific weighting sets and valuation methods, and accounting for service-sheds and critical thresholds that determine sustainable service use. These remain challenges, but this work establishes a practical step toward integrating ecosystem services into life cycle frameworks and provides evidence to inform afforestation, land use, and timber policy in Wales.

Date of Award	14 Jul 2026
Original language	English
Awarding Institution	Bangor University
Sponsors	Woodknowledge Wales
Supervisor	John Healey (Supervisor) & Ashley Hardaker (Supervisor)