March 28, 2017
SIF tour of integrated harvesting on Veon site in Laois
Veon hosted an extremely well-attended field day with the Society of Irish Foresters on a harvesting site near Clonaslee, Co. Offaly. The event was carried out as a dissemination activity of the EU Seventh Framework programme project – SIMWOOD.
The event focused on harvesting of Sitka spruce/Japanese larch, Norway spruce and Oak/Scot’s Pine stands planted in 1998 on a surface water gley soil. Forest roading and the construction of a large span bridge were also reviewed.
The main focus of the day was Integrated Harvesting. In integrated harvesting the harvester processes small sawlog, delimbing and presenting at the side of the rack in the normal way. The remainder, including stem wood which would normally be categorized as pulpwood, is also processed into variable lengths of fuelwood leaving as much branch material on the stem as possible. Tops and branches are set to the side of the rack in separate bunches. A forwarder removes the small sawlog and fuelwood to roadside. The tops and branches are left within the plot to dry. The small sawlog is removed shortly after harvesting to a sawmill while the fuelwood is left to dry at roadside till the moisture content reduces to around 45%. This will take about 6-9 months depending on the site and time of year. It is then chipped and taken to a bioenergy facility. Once needles are cast from the tops and branches (minimising nutrient loss), this material is forwarded to roadside and chipped. This harvesting method has been shown to significantly increase the total biomass recovered from plantations.
Daragh Little, Managing Director Forestry at Veon, said that while Integrated harvesting can demonstrably provide a solution for many forests, there will be considerable variation from site to site. Veon has been working on a Decision Support Tool to help foresters predict the amount of extra material that can be extracted and whether it is a viable option. The main criteria in the tool are, soil type/drainage, access/stacking space, tree quality and distance to market.
Within the woodland chosen by Veon for the demonstration, integrated harvesting was prescribed in the Sitka spruce/Japanese larch (SS/JL) and Norway spruce (NS) plots. The site has good access after the construction of a long span bridge and harvesting road in 2016 and markets are also readily accessible. The site although marginal in terms of soil type and bearing capacity was flat and was deemed to be able to carry the forwarder traffic.
In the case of the SS/JL plot, it was prescribed due to the poorly formed crop, especially JL which was suppressing SS. In the case of the Norway spruce, thinning was on time, but typically in Norway, the variability in tree size meant that the value of the timber sale would be low
The Harvesting Operation
Harvesting started in November 2016 and completed in January 2017. Forwarding of pallet and biomass material was completed. Haulage of Pallet material started in late December and is ongoing. Biomass material will be left on site until June/July or until moisture content reduces to circa 45%. It will be chipped on site and taken to Edenderry Power. At that point the forwarder will return to remove branches and tops to roadside. It is anticipated that needles will have been cast by that time. That assortment will then be chipped and transported to Edenderry Power.
While the operation was still ongoing, Veon were able to estimate the amount of material that will eventually be removed at approximately 90 m3 /ha. This is very substantially above traditional harvesting where 50 m3/ha could be expected. This will result in a substantially increased income for the forest owner when the work in completed. On previous sites Veon was able to increase forest owner’s income by over 50%.
Daragh Little, Managing Director Forestry at Veon said that while Integrated Harvesting has many positives there are issues that foresters and forest owners need to bear in mind. The length of time of the operation can be up to 6-9 months longer than traditional harvesting, with consequent increased costs and security to contend with.
Traditionally, timber has been sold in tonnes over weighbridge. This is not appropriate when selling fuelwood. In order to provide transparency and increase trust, foresters need to move towards selling fuelwood in gigajoules based upon moisture content and calorific value of the material they are selling. This is very important when one considers that most of the increase in timber mobilisation in the coming decade will be in bioenergy. A new language needs to be learned by foresters to protect their client’s interests.
Bridge and Road Construction
Access to this property was significantly challenged due to the presence of the River Barrow and its status as a Special Area of Conservation (SAC). Before this bridge was constructed access was by way of a ford. However, to facilitate timber extraction, it was necessary to construct a bridge. The bridge went through the normal planning process with significant input from the National Parks and Wildlife Service and Local Fisheries board. The bridge was then constructed in the summer/autumn of 2015.
A road was then laid out in 2016 and grant aid was applied for under the Forest Service Road scheme. Some 900 metres of road was constructed in in November/December 2016. Some discussion was had on the inputs of foresters into road construction and the specifications required. All Veon foresters are PCSC certified to aid and facilitate their clients when there is a requirement for forest road and bridge construction on forestry sites.