The distribution area (range) of various forest insect pests is huge, due to the spatial distribution of susceptible tree species. Consequently, only those forests that are most vulnerable to the attacks of an insect are targeted for treatments on account of the risks of mortality that can, in turn, produce major socioeconomic impacts.
The delimitation of areas qualifying for direct protection interventions is based on forest and operational criteria defined by the Quebec Ministry of Natural Resources. SOPFIM’s mission consists in applying these rules and performing mapping, aerial validation and annual updates of data. Criteria for areas qualifying for aerial spraying
This mapping tool provides information about those sectors which, where applicable, could qualify for protection based on the aerial spraying of organic pesticide. The treatment prescriptions proposed by SOPFIM apply only to qualifying areas, with the exception of special requests approved by the Quebec Ministry of Natural Resources.
Areas that have not been selected for this type of intervention must undergo preventive measures, including thinning or remedial actions, such as early harvesting (i.e., pre-salvage harvesting) or the salvage harvesting of damaged forests. In some cases, there are no particular alternatives available, and so the authorities either accept the loss of timber or go forward with silvicultural activities helping to offset these losses.
At the end of a forest pest’s seasonal activity period, the Quebec Ministry of Natural Resources carries out an aerial inventory of the annual defoliation caused by that insect. The various vulnerable forest masses are thus mapped according to the following defoliation classes: Light (1% to 35%), Moderate (36% to 70%) or Severe (71% to 100%). This input is of considerable value for determining the relevance of interventions designed to control damage.
These data provide an annual snapshot of the extent and severity of infestation over a given territory. Managers can use a succession of several annual cartographic documents to visualize the progression of an epidemic as well as the reoccurrence of damage within specific sectors. Thanks to this approach, they are better equipped to plan interventions in terms of windows of opportunity and the particular characteristics of the territory under their responsibility.
During the fall period, an inventory of hibernating insect populations is carried out for the purpose of determining the anticipated levels of infestation and damage for the following summer season. Accordingly, the Quebec Ministry of Natural Resources conducts extensive detection surveys in forests susceptible to attack by insect pests, while SOPFIM performs intensive sampling in the heart of infested sectors, all with a view to planning direct protection interventions (in selected areas) based on the aerial spraying of organic pesticide.
In the case of the spruce budworm, the results of the hibernating larvae (L2) inventory, expressed as larvae per 10 m2 of foliage, can be used to predict both the population level and the associated defoliation level according to the following classes: Nil (0 L2/10 m2), light (1 to 188 L2/10 m2), Moderate (189 to 540 L2/10 m2), High (541 to 1,184 L2/10 m2) and Very High (> 1,184 L2/10 m2).
These predictions serve primarily to frame the choice of Btk treatments to be applied over a specific area; they also guide managers, who are thus able to anticipate the expansion of the epidemic and adjust the intervention plans in consequence.
During periods of epidemic, the Quebec Ministry of Natural Resources periodically carries out an aerial inventory to assess the health status of infested forests. This survey supplies cartographic data representing the cumulative defoliation level and the mortality rate of trees across a territory confronted with a major epidemic.
For managers, this type of information can be used to plan wood salvaging operations in accordance with priorities established on the basis of the mortality rates observed in forest stands. Whenever the mortality rate accounts for more than 50% of the standing timber volume on areas qualifying for aerial insecticide spraying, these sectors are withdrawn from the direct protection program and designated for salvaging operations instead.
On the basis of information made available in fall – including the annual defoliation observed over the territory, the projected insect population/damage levels, forest health status, timber harvesting projections, and the protection priorities set out by the government of Quebec – certain qualifying forest sectors are included in the aerial organic pesticide spray program.
The cartography of treated sectors depicts the annual insecticide spray program conducted by SOPFIM. Notwithstanding the pinpoint planning of a pest control program (i.e., planned sectors), various events occur that may entail making changes to the initial intervention plan. Qualifying areas that were selected for treatment may have undergone natural disturbances (e.g., windfall, fire) or modifications of the harvesting plan. Some years, unfavourable weather conditions occurring during the period targeted for aerial insecticide spraying make it impossible to carry out the program as planned. In respect of the targeted insect, adverse winter or spring weather conditions may cause a significant level of mortality, thus reducing the need for treatments.
For a given insect, managers requiring cartographic data can make a query by selecting the desired elements in various drop-down menus. The cartographic documents can either be consulted online or downloaded for personalized use.
Important: Concerning a province-wide query, the result can be viewed on screen but the full set of digital data (in shapefile format) cannot be downloaded in a single unit. In that case, users should perform queries by region or use the PDF format.