Forest Health

The National Forest Pest Strategy and Monitoring of Major Forest Disturbances: A Summary of Current National Forest Health Monitoring Surveys

In 2006, the Canadian Council of Forest Ministers (CCFM) endorsed the idea of a National Forest Pest Strategy (NFPS) to address both native and alien forest pest species. In collaboration with the provinces and territories, Natural Resources Canada and the Canadian Food Inspection Agency are working on behalf of CCFM to generate baseline knowledge for the development and implementation of a NFPS. Canada’s present approach to forest pest management has been largely reactive, based on historical knowledge and focused on pest-specific stand-level management. It was recognized that a coordinated, risk-based, ecosystem, national approach was required.

The NFPS’s Implementation Plan has six general components, one of which is monitoring and diagnostics. The primary objective of the monitoring and diagnostics component is to build on current information and existing capacities to develop a national pest monitoring system. Monitoring will include both native and non- native pests, and be of sufficient quality and resolution to be used for risk assessment.

The first step in fulfilling the monitoring and diagnostic objectives was a national monitoring capacity analysis, which was completed in the winter of 2008/2009. A detailed monitoring questionnaire was completed by 10 provinces, one territory and the Canadian Food Inspection Agency (CFIA). A total of 372 different activities were reported. Analysis of the responses found there are a total of 82 Major Forest Disturbances (MFDs) currently being monitored across Canada. 60% are forest insects, 13% are exotic pests, 11% are forest tree diseases, with the remaining 7% categorized as tree species decline, general surveys, and abiotic and wildlife damage.

The monitoring surveys themselves are very diverse and are not necessarily conducted annually. Some are specific to a geographic area, and others, such as defoliators, are monitored on an as required basis. Three-quarters of the surveys are ground-based, of which over a third provide information on insect populations. The remaining surveys consist of a variety of aerial survey methods. Monitoring methodologies, even for the same MFD, vary considerably across the country. These differences are in part due to differences in pest behaviour and/or host species and have been developed based on local knowledge and conditions.

The largest variety of MFDs monitored across all provinces and territories (with the exception of Ontario) are specific native or established defoliators. Eastern spruce budworm, followed by forest tent caterpillar, are the most widely monitored damaging defoliators in the country. Jack pine budworm is also widely monitored except for Western Canada (AB, BC & YT) where it is not a MFD. Conversely, western spruce budworm, Douglas-fir tussock moth, and two-year-cycle budworm are MFDs found only in Western Canada, and hence monitoring efforts are focussed in the western provinces. Non-defoliator types of surveys are less common and vary both in the type of survey and the extent to which they are conducted nationwide. The most common non-defoliator type of survey is that for bark beetles. Surveys that capture multiple MFDs are most common in Ontario where host or forest type-based pest monitoring is undertaken.

Critical data gaps were found in monitoring of the "unknown" i.e. forest health factors, including exotics, which are not currently considered MFDs. These potential MFDs can be very difficult to determine, particularly with climate change and invasive exotics’ complications. Transportation of people, animals, and various goods worldwide is now commonplace and increases the risk of introduction of non-native insects and diseases. Exotics are primarily monitored by the CFIA. The CFIA has effective monitoring systems to identify alien pests in four high risk Canadian cities, but many other urban areas are at risk for undetected invasion by exotic forest health agents. Increased aerial overview survey coverage across forested areas is recommended to address this issue at the landscape level as well as increasing urban forest monitoring. For those MFDs that are not visible during aerial overview surveys, a national monitoring system using PSPs is currently being considered. These would include existing PSPs currently being monitored by the provinces and territories. The goal would be to monitor changes in pest populations, including species and behaviour changes, new species, and changes in host response/impact.