When the Mountain Pine Beetle (MPB) arrived in Alberta some nine or 10 years ago it hit hard. Whole areas of pine trees were red with dead or dying trees, and people everywhere were losing trees on private property, golf courses were losing trees, towns were losing trees from boulevards as the beetles which had dug in under the bark, spreading the fungus that killed pine trees.
Now, the MPB has faded from the news but the effect is still here. Some mills decided they would take the dead pine trees but only up to three years after death. However, some have continued to take the trees, in spite of the difficulties. The trees are very brittle and shatter easily being loaded, being moved, going through the saws. The sawdust produced cutting them is much more flammable and is blamed for the destruction of two sawmills.
While all of this is interesting, some important research has been going on into how to help the forest recover from the MPB infestation.
In some areas it seems like a bad idea to replant pine trees, but the ground where they grow is not as well suited for growing other types.
Scientists from the University of Alberta and the Canadian Wood Fibre Centre of Canadian Forest Service are working with the lumber industry to find the best way to get the forest back into production.
They are exploring the best way to plant trees in MPB killed areas.
There are different ways they have explored. One is planting the trees directly into the soil with no disturbance. Others are scalping, mounds and mixed: scalping is scraping off the top layer of organics and top soil to expose the mineral layer underneath. Mounding is scraping the organics and top soil up, dropping it upside down and planting the tree in the resulting mound. Mixing is mixing the top soil and mineral soil underneath to plant the seedling.
In one area they have planted only white spruce, in other areas they have planted lodgepole pine. The aspens seem quite good at regenerating themselves without any help from what could be seen at the sites.
One area which was selectively logged on an experimental basis relied on a careful layout of corridors for the buncher, feller grapplers to drive in, cut down the trees they want and send them down the line to the landing yard. New trees were planted using the above mentioned methods.
If the area is logged again in the future, the new corridors will avoid the new trees were planted (unless of course, they have grown to marketable size).
Last week, May 11 and 12, there was a a Mountain Pine Beetle and Stand Rehabilitation Research Forum and Field Tour. The Canadian Forest Service, University of Alberta, fRI Research (Informing Land & Research Management) and different forestry companies including Canfor and Spectrum took part.
As U of A researchers Dooley (Victor) Lieffers and Ellen MacDonald said, three years should give a good indication of which methods work better for planting trees but five or 10 years will make it even clearer. Their research plot is labelled long-term monitoring project and the project may live on beyond their own research careers.
Other research has been going on – Hugh Wallace of the U of A has been looking into the fire risks posed by the stands of dead pine.
He explained there are different layers of fuel. On the forest floor, there is the light fuel – leaves, twigs, moss, all of which is quite dry quite now and would burn quickly like grass. Heavy fuel, like logs lying on the ground are heavy fuel, but aren’t not necessarily ignited by a fire in the light fuel.
For the fire to get into the canopy, the fire has to either creep up the bark or smaller trees have to catch and send the flames up to catch.
He said the corridors put in for logging equipment access may help the light fuel dry more quickly and help fire on the ground spread more quickly, but does act as a fire break when it comes to the heavy fuel burning.
Sometimes logging sites are left with waste material and one contractor in Canada has a machine which can shred and bale that material. They had that contractor bale some of their waste material – the bales are round, wrapped in plastic netting and weigh 800-1200 kgs apiece.
They have found no moisture and zero decomposition in the bales after one year and at another site, even three years later there is no sign of decomposition. The bales can be sold for landscaping mulch, although the contractor intends to sell them to oilfield as spill kits.
Sharon Meredith of FGrow was one of the final speakers. FGrow has been in operation for one year, but is the result of the amalgamation of four other organizations so it is continuing research started by them.
FGrow is looking into mortality rates for pine stands attacked by MPB. They have found that while some stands have quite high mortality rates, there are 15% that have only a 25% mortality rates and they are studying weather patterns and other data to see where the reason for the difference might lie.
They visited 104 sites over the years, but focused on 63 of them. Now they realize they probably focused more on sites with higher mortality rates and will be trying to get back to the other sites.
Alberta Forestry representative Brooke said the MPB situation is one of continual learning and adaptation, “implementing what they learn on the ground to meet the goals of mitigating the effect of MPB.”
He was asked how they would make the decision to bulldoze a stand of MPB killed pine or not. He responded, explaining they would have to look at what value the dead pine might have – from an ecological viewpoint or any other viewpoint – then figure out what their priorities are. “You can’t treat every pine stand in the province. We don’t want to pump our money into a stand that would recover on its own,” he said.