Transformation of Sitka spruce stands to Continuous Cover Forestry (CCF)
Fifty-two percent of the stocked forest area in Ireland is Sitka spruce. Forest management in Ireland is dominated by the clearfell system; a system that normally entails even-aged structure of the forest. There has been increasing interest in recent years in Continuous Cover Forestry (CCF); an approach to the sustainable management of forests whereby forest stands are maintained in a permanently irregular structure by single tree selection and harvesting. Coillte has adopted a low impact silviculture policy (including CCF) in its broadleaf estate and increasingly private forest owners are also transforming their forest stands using CCF principles.
There is little guidance available related to transformation to CCF in Ireland. The COFORD-funded Low Impact Silvicultural Systems in Ireland project (LISS), led by UCD and completed in 2014, began the process of filling knowledge gaps.
A new 5-year Teagasc-funded project began in 2017, in collaboration with UCD, that will develop the LISS, which studied the initial stages of transformation of two Sitka spruce stands, by investigating their progression and continued management interventions.
Three thinning treatments were used. The stands are on a 3-year thinning cycle and due to be thinned in 2017 and 2020. This project will continue the transformation process by carrying out these thinnings and investigating their impact on stand transformation.
- To build upon a previous DAFM-funded project and further investigate the impact of two thinning treatments (graduated density thinning and crown thinning), relative to the control low thinning treatment, on the transformation of pure Sitka spruce stands to CCF after the third thinning intervention
- To provide an assessment of the potential economics, stand stability, impact on diversity and crown cover, of using such thinning regimes.
- Data from the six Irish AFI (Association Futaie Irrégulière) stands will be evaluated to determine how management in these stands influences stand structure.