A GIS-based site suitability assessment of harvest residue procurement during integrated first thinning operations in southern and eastern Ireland

Abstract

The Irish forestry sector faces a wood mobilisation challenge as many forest owners do not engage in forest management. Simultaneously, demands for biomass continue to increase to meet the requirements of national and European policies regarding the use of renewable sources of energy. First thinning operations in Ireland are normally conducted through Cut to Length (CTL) practices. In this study, Integrated Thinning (INT), a practice that procures woody residues in addition to the conventional roundwood assortments, was evaluated as an alternative, leading to higher profits that may increase forest owners’ engagement with management. This study was part of SIMWOOD, a European project aiming to increase the mobilisation of wood from forests and woodlands in Europe and assessed the sustainability of INT in the south and east of Ireland. Results include geographic datasets describing harvesting operations at the forest areas of interest, soil damage and nutrient loss risks, and distance to the nearest biomass end users. It was found that c. 42,000 ha of forests had reached a suitable age for first thinning, of which c. 22,000 ha were on soils where INT could be conducted. Additionally, 99% of the area where INT could be implemented was less than50 km from the nearest biomass end user. To increase wood mobilisation INT appears to be a useful alternative to CTL; however, its sustainability depends on site- and stand-specific variables and also depends on other aspects not considered in this study, such as weather conditions or market drivers.