Alberta is trying different ways to capture value from stands impacted by mountain pine beetle in particular small stem lodgepole stands with over 50 percent mortality.
These stands have been avoided by forest companies because of their low commercial value but it left untreated they could have significant impact on the health and production of future commercial forests.
Derric Sidders from the Canadian Wood Fibre Centre (CWFC) describes a project where they are using a full tree selective systematic harvesting pattern on parallel machine corridors.
The machine corridors are five metres wide centered at 20 metre intervals and are serviced with a 30 wide landing. The machines can harvest from either side of the selection strips which make up to 75 percent of the treatment area.
Selection from within the selection strips consists of pine attacked trees along with ones with commercial product value and other stems impacting stand health and vigour.
White spruce and aspen are only harvested from the machine strips and sorted for sawlog, Oriented Strand Board or biomass production. The goal is to leave a healthy stand with three-metre spacing between trees.
It is a challenge for machine operators as they must harvest along the corridors and back out to the landing creating bunches of selected wood. All bunches for skidding face the landing and consist of green, red and grey pine along with white spruce and aspen. The material is processed at the landing based on the demand for the various products.
Biomass is mulched, chipped and compressed baled using a Gyro-Trac Biomass bailing system creating 700 to 1,000 kilogram bales destined for the bioenergy or oil and gas sectors.
Time and motion studies are being done on all phases of the operations so investigators (FPInnovations) can make the most of the work being done.
Some may object to the strip harvest approach which is not suited to steep topography and is less desirable than curved natural boundaries but may work on some of our extensive flat pine stands in the Chilcotin.
As Sidders points out they have been able to capture some value from their sites, tentatively reduce fire risk and enhance the stands to put them on a more productive trajectory to meet future needs.
This work will require a different approach in terms of licencing, stumpage and silviculture policies and regulations but could be a way of reducing the impact of sawlog reductions from the pine beetle losses.
We would be wise to start with research and development sized trials to get information necessary to move to a more commercially viable operation. These trials could include harvester forwarders that could be used in stands that have more natural boundaries and require less processing along with smaller landings.
We should also look at various ways to get the biomass to the cogeneration and pellet plants which will meet the anticipated shortfall of mill waste from the declining lumber production.
For more information contact derek.sidders@nrcan.ca.
Jim Hilton is a professional agrologist and forester who has lived and worked in the Cariboo Chilcotin for the past 40 years. Now retired, Hilton still volunteers his skills with local community forests organizations.