A whole new dimension to woodland management
Published 24/06/2015 | 02:30
Harvesting and chipping entire trees is a woodland management system that is new to most of us but given the current demand for wood chip it appears to be a useful option. Everything, including the branches gets used up, so it really is only appropriate on dry sites that don't require brash mats for heavy equipment.
At a recent demonstration in a plantation of Sitka spruce and larch at Dungarvan, near Gowran in Co Kilkenny, we saw how the entire tree is harvested, stacked to dry for up to a year and then chipped and sold on to either power plants or the private sector.
A lengthy drying period also allows the needles to fall off but even after a year, moisture content is often still over 40pc. Power plants can burn chip at up to 50pc moisture content but the smaller burners such as those used in large houses, nursing homes and small hotels require drier material.
The COFORD report on 'Mobilising Ireland's Forest Resource' recommends increasing whole tree harvesting to reduce the forecast shortfall in the supply of wood biomass in Ireland. The report estimates that by 2020 demand will exceed supply by 2.1 million m3 per year.
Forest based biomass is projected to see the largest rise in demand due to government targets on renewable energy.
Forest Enterprises Ltd were in charge of managing the site we visited. They recommended that thinning take place early due to the exposed location and the presence of some poorly performing larch.
Early thinning helps protect against wind blow later on and also provides a faster financial return. Worrell Harvesting were employed as contractors and thanks to an excellent internal forest road, they were able to use some of their huge equipment to both chip and haul the produce in lorries which clearly wouldn't be able to access smaller sites.
They also use tractors and trailers and smaller chippers ,where conditions demand it, but double hauling should be avoided where possible as it can add €10 per tonne to the total costs.