MNRF Forest Health Update in Ontario

MNRF Forest Health Update in Ontario

I recently listened in on a webinar that was released by the Ministry of Natural Resources and Forestry (MNRF) on the annual update of forest health monitoring in Ontario. The presentation was made by Dan Rowlinson who works in the Biodiversity and Monitoring Section of the MNRF. The MNRF conducts regular annual monitoring throughout the province to track various invasive pests, diseases, and natural disturbances. This type of monitoring helps provincial managers to plan for pest management activities, design research projects, develop invasive species strategies, climate change programs, and evaluate forest biodiversity. The monitoring includes mapping areas to document how much area is affected by various stressors and determine how severe the damage is. Monitoring also involves collecting insect and disease samples to track where they occur and how abundant they are. The MNRF surveys each year for specific forest pests, specifically those that are invasive or could have an impact on biodiversity.

It was reported that 2020 was an interesting year with respect to COVID19 and the number of people who have different daily schedules/routines as a result of provincial lockdowns. Many people were working from home and spending more time in nature, so citizen science reports on various changes on the landscape were much larger than in past years. Part of forest health monitoring includes reviewing photos and reports from the public around various forest pests (both native and invasive) which is an important part of tracking certain species. This will also likely be the way forest health managers are able to identify and control species such as the Asian Long-horned Beetle which has been declared eradicated in the province.

Common pests that were reported on include Forest Tent Caterpillar (Malacosoma disstria Hubner) which was reported with no outbreaks confirmed in 2020 and was a good news story. Forest Tent Caterpillar is a pest native to North America and in 2019 35,220 ha of forest was infested with the pest. It was reported that in 2020 there was no defoliation recorded during aerial surveys or field observations. While this pest is very cyclical in nature, presently, infestations are low.

Spruce Budworm (Choristoneura fumiferana Clemens) defoliation and infestation was higher in 2020 in comparison to 2019. This is a native pest that defoliates Balsam Fir, White Spruce, Black Spruce and Red Spruce. The majority of the infestation and mortality is focused in the northeast region of Ontario and a type of control program is in the planning stages for 2021 to help manage the outbreaks of this pest which is also cyclical.

Jack Pine Budworm (Choristoneura pinus pinus) is another native defoliator that goes after host species including Jack Pine, Red Pine, Scots Pine and White Pine. Defoliation in 2020 was focused in the northwestern part of Ontario reaching over 1 million hectares. This disturbance is known to have an economic impact as well as an environmental impact due to the large amount of mortality that is associated with outbreaks. For this reason, managers spend resources planning and implementing control programs for this pest.

Gypsy Moth (Lymatria dispar) is an invasive pest that is native to Europe and defoliates species including Oak, Birch, Aspen and other hardwoods. In 2020, the population of Gypsy Moth was extremely high and the defoliation was extremely visible on the landscape. Much of the impacts of this pest was focused in southern Ontario. This pest has been monitored and managed since the 1980s and what we see now is that this species is naturalizing on the landscape where we see cyclical outbreaks. While there are still major areas of defoliation, there is evidence that predators are working to help control the population. Because much of the area of Ontario that is impacted by this species is also focused in higher population areas, time and resources were allocated this past year to providing education and outreach to concerned citizens around Gypsy Moth.

For anyone interested in learning more about these species and looking through mapping that has been produced by the MNRF related to the monitoring and field data that is conducted each year, that information is available through the Ontario government website at:

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