Forest health monitoring in Ontario is conducted as a partnership between the Ontario Ministry of Natural Resources (OMNR) and Natural Resources Canada-Canadian Forest Service (CFS). This federal-provincial collaboration began in the 1930s, and has been formalized under a series of memoranda of understanding.
Recording and reporting of forest health conditions in Ontario includes monitoring the occurrence of both native and invasive biotic (e.g., insect, disease), and abiotic (e.g., severe weather conditions) disturbances and events. The monitoring program consists of permanent sample plots, temporary sample plots, plantation surveys, and aerial mapping of major forest disturbances. All forest areas are included: provincial Crown land, federal lands, First Nations territories, parks, and private land and urban areas. Ad hoc sampling of insects and diseases is also done to maintain a database of their occurrence in the province.
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Forest Health Conditions in Ontario, 2011 (Published date - March 1, 2012) (PDF, 6.8 MB 109pages)
Executive summary
The Forest Health Conditions Report presents the results of annual surveys and monitoring conducted by the forest health monitoring partnership in Ontario. It is published by the OMNR as part of the partnership between OMNR and the CFS. The report is a continuation of a series of annual Forest Health Monitoring reports produced by the CFS from 1995 to 2003, which was preceded by annual reports of the Forest Insect and Disease Survey, also produced by the CFS. The report is divided into chapters of major forest disturbances, invasive species, and regional reports for each of OMNR’s three administrative regions.
2011 Summary of Events:
Extreme weather events
Several extreme weather events in 2011 resulted in damage to the forest as well as to buildings and infrastructure. There were 17 tornadoes reported for the province, compared to an annual average of 13. The most powerful tornado to hit Ontario in 15 years was an F4 tornado on August 21 that struck Goderich. The tornado then moved inland approximately 20 km with a swath up to 1.5 km wide. This event damaged buildings and structures in the town, flattened forest areas along its track, and resulted in one death. Other tornadoes occurred near Gananoque, northwest of London, near Cambridge, in the southwest portion of Grey County, near Watford in eastern Lambton County, near Missinabie northeast of Wawa, and in the Goose Lake area of north western Ontario.
The dry weather in north western Ontario resulted in visible symptoms of severe drought. For the first time in several years the drought was widespread and continuous enough that it could be aerially mapped. Most of the affected area stretched from northeast of Sioux Lookout in a north westerly direction and affected forest stands on either side of Lac Seul. The affected area totalled 360,900 ha.
Insect infestations
The jack pine budworm (Choristoneura pinus pinus Free.) outbreak which began in 2004 and peaked in 2007 continued its decline in 2011. Only small amounts of defoliation occurred in pockets in all three regions. The 2011 defoliation of 27,765 ha represented a 40% decline from the 2010 defoliation of 44,968 ha. Defoliation persisted in Sudbury and Timmins districts in North East Region, in Sioux Lookout District in North West Region, and in Parry Sound District in the Southern Region. Given the steady decline in recent years of the jack pine budworm outbreak, limited defoliation is expected in most of Ontario in 2012, although there may be some persistent pockets in all three regions.
This collapse is typical of outbreaks of this insect, which are characterized by 2-3 years of severe defoliation in a given area, followed by abrupt population collapses. The current outbreak began in Northeast Region in 2004, where it slowly built up over several years. In Northwest Region the outbreak began one year later and showed a rapid increase in defoliation. In both regions, defoliation in one area persisted for 2-3 years, with a collapse in one area being followed by a rise in defoliation in another part of the region. Overall, the Southern Region had much less defoliation, but like Northeast Region the populations here built up much more gradually than those in the Northwest. Peak defoliation occurred in 2007 when 740,116 ha of moderate-to-severe defoliation were aerially mapped. In Southern Region the jack pine budworm outbreak also has been quite localized, with severe defoliation in Algonquin Park and Bonnechere Provincial Park, and along the eastern shore of Georgian Bay east to Hwy. 69.
Spruce budworm (Choristoneura fumiferana Clem.) continued its oscillating outbreak which has been concentrated in Northeast Region. Moderate-to-severe defoliation affected 242,921 ha in 2011. This was a 40% decline from the 412,320 ha that occurred in 2010. In contrast, the 2010 defoliation was a 40% increase over the 291,592 ha that occurred in 2009. While this outbreak has continued for several years, the current spruce budworm defoliation has yet to erupt into a province-wide event such as the previous outbreak that peaked at over 18 million ha in 1981. Nonetheless, tree mortality has continued in the affected area in Northeast Region, with cumulative white spruce and balsam fir mortality reaching 182, 512 ha in 2011.
Forest tent caterpillar (Malacosoma disstria Hbn.) has cyclical outbreaks in Ontario, occurring approximately every 10-12 years. This insect is currently at endemic levels in most of the province with a new outbreak expected to begin in the next 2-3 years. Since 2009 forest tent caterpillar defoliation has occurred in Southern Region, but it has yet to erupt into a full outbreak. While the Southern Region defoliation began with 8,912 ha of moderate-to-severe defoliation north of Kingston in 2009, this area has not been defoliated since then. The 2009 defoliation was however followed by 60,427 ha of moderate-to-severe defoliation in 2010, and then by 54,623 ha of defoliation in 2011. In both 2010 and 2011 the defoliation occurred in pockets from Bancroft west to the Bruce Peninsula and Goderich. In most cases it was not the same stands being defoliated in each year. Thus it is not yet clear whether this represents the beginning of a full fledged provincial level outbreak.
Several other insects caused localized defoliation or damage in various parts of Ontario. In most cases, though, forest insect populations were relatively low compared to 2010. This is likely a result of the cool wet weather conditions in 2009 and 2010 that favoured tree growth and suppressed or slowed insect growth and phenology.
One exception was an extensive area of septoria leaf spot (Septoria betulae) and birch leaf skeletonizer (Bucculatrix pometaria (Harr.)) that resulted in premature yellowing and browning of the leaves of white birch. For the second year in a row, this late-season event occurred in Northwest Region. Almost all the white birch trees in the affected stands in the region had either or both septoria leaf spot or birch skeletonizer on the majority of their leaves.
Foliar diseases
The warm dry weather of 2011 did not favour foliar diseases, especially in comparison to 2009 when these events were prevalent enough that they could be mapped from the air for the first time. White pine browning was again observed in Ontario, but was much less prevalent than in previous years. Unlike 2009, white pine browning was not severe enough to be mapped from the air. The forest health program and the Ontario Forest Research Institute continued to work with the Canadian Forest Service – Laurentian Forestry Centre to identify the cause of this phenomenon.
Tree decline
In 2009 and 2010, aspen decline and mortality was recorded as a widespread event in Northwest Region. This damage was described as unhealthy-looking aspen with thin crowns, branch dieback, and in some cases tree mortality. In 2009 some 3,803,807 ha of aspen decline occurred from Fort Frances to Red Lake and Geraldton. In 2010 this increased to 12,767,043 ha of light aspen decline, and 3,114,134 ha of severe decline affecting all districts in the region. By 2011 however, aspen decline was no longer evident. Most of the aspen showed good recovery, with fully-leafed crowns and normal-sized leaves. Only 3,117 ha of severe aspen decline were aerially mapped in 2011. Aspen health plots were established in 2010 and 2011 to quantify the amount of decline and to determine the possible cause(s) of this phenomenon.
Invasive alien species surveys
Surveys for several invasive alien species continued in 2011. The exception was the delineation survey conducted since 2005 for sirex wood wasp (Sirex noctilio F.). This survey was not conducted in 2011. No new finds of this insect were made in the 2008 and 2009 surveys conducted by OMNR with the financial support of the Canadian Food Inspection Agency (CFIA). These surveys were conducted using Lindgren funnel traps baited with an alpha and beta pinene lure that is the best option currently available but known to be relatively poor at attracting sirex wood wasp. With the discontinuation of the CFIA support in 2010, OMNR conducted a project with the CFS to cut and rear pine logs from suspect trees. Suspect trees were cut from survey sites and placed in rearing cages and then monitored for emergence of sirex wood wasp. No sirex wood wasp adults were reared from these collections made in 2010 and monitored for sirex emergence until 2011. Because the suspect trees were cut in areas where the insect was thought to be at the leading edge of its distribution, it’s not known whether the lack of any sirex wood wasps from the logs was because the trees were not infested, or whether the rearing method did not allow them to emerge.
Asian long-horned beetle (Anoplophora glabripennis Motschulsky) which was first discovered in the border area of Toronto and Vaughan in 2003 remained under an active eradication program. The aggressive survey and tree removal program under the authority of the CFIA has been followed-up by annual surveys by municipal staff to search for the beetle or for infested trees. This work has been done under the direction of the CFIA and with scientific guidance from a science panel chaired by the CFS. No Asian long-horned beetles or trees with signs or symptoms of infestation were found in 2011 surveys. This marks the fourth year of no new finds for this insect, indicating that the potential remains high for complete eradication.
In contrast, emerald ash borer (Agrilus planipennis Fairmaire) continued to spread and cause tree mortality. A single beetle was caught in a CFIA green prism trap baited with a green leaf volatile lure at two locations: near Sheguindah on Manitoulin Island, and near Wendover in Prescott and Russell County. Tree decline and mortality was aerially mapped in numerous pockets in south western Ontario resulting in a cumulative total from 2004-2011of 62,616 ha. An additional 753 ha was aerially mapped for the first time in eastern Ontario in the Ottawa area.
Insect pest management programs
Only one insect pest management program was conducted by OMNR in 2011. The containment program for the pine shoot beetle (Tomicus piniperda (L.)), an invasive species from Europe, was continued in 2011, with 39 sites along the leading edge of the infestation. Population estimates from the bait logs, coupled with fall visual surveys for shoot attack, indicate the program has been successful in keeping the populations low with very few beetles (< 10) found at each site. Lindgren funnel trapping and visual surveys in 2011 and in previous years have not found pine shoot beetle north of this leading edge, indicating the insect remains contained to the south.
Forest Health Research Projects
Several research and health monitoring projects were undertaken in 2011 with the support of forest health field staff. Results of these projects are published as appropriate by the lead scientist, and are beyond the scope of this report. These projects included:
In partnership with CFS-Northern Forestry Centre, annual monitoring of the CIPHA (climate change impacts on the productivity and health of aspen) plots in northern Ontario.
- Testing of detection methods for emerald ash borer.
- Testing of a detection method for European oak borer (Agrilus sulcicollis Lacordaire).
- Development of DNA methodology for identifying butternut trees resistant to butternut canker.
- Evaluating the optimum pheromone and trap type and placement for jack pine budworm.
- Provision of white pine logs for placement in mountain pine beetle (Dendroctonus ponderosae Hopkins) infested stands in Alberta to investigate the suitability and preference of white pine as a host for the beetle.
- Collection of jack pine foliage for a range-wide DNA analysis
- Collection of spruce budworm moths for range-wide DNA analysis
- Field testing of a pheromone for pine false webworm (Acantholyda erythrocephala (L.))
