Climate Change in Ontario

Issue: 
November-December 2007

AFTER ALL THE SCARY PREDICTIONS, climate change is here. Three different climate models indicate that around 1990 that change started to escalate. The sun still rises in the east and the trees are still growing ring upon ring, but we are facing new challenges and there are more to come. Stephen Harper signed a joint statement with Australia saying, “Both countries agree that reducing emissions from deforestation is a key component to global action on climate change.” There are lots of people debating the details but reason says he isn’t planning to reduce forestry or urbanization, so to keep that promise we have to plant more trees for carbon storage.

That simple statement means a lot of work for foresters, arborists and researchers. Because to make a difference, “trees” must include rural, urban forests and front lawn ornamentals. Generally accepted as a minimum average, we need 30% forest cover in all urban areas. That’s an easy target for some, but a dream for other regions.

The concept that trees can help in the fight against climate change has science backing from some interesting places. A study on the changes in forest biomass carbon storage between 1949 and 1998 in China says, “Carbon storage increased significantly after the late 1970s mainly due to forest expansion and growth.” This suggests that we can store more carbon in our trees if we practice better forest management techniques helping us meet our Kyoto Protocol targets. Carbon Storage in Ontario’s Forests states that about half of every kilogram of wood is C and every kilogram of C that is in a tree represents about 3.7 kg of C02 removed from the atmosphere.

Here are a couple of predictions for Ontario’s future. Cherry’s 2001 report, Options for allocating afforestation stock in Ontario with anticipated climate change, says that northwestern Ontario is expected to be warmer and drier and that some species in southern Ontario may be extirpated as ranges shift northwards. Furthermore, white pine, red maple and green ash are expected to be less affected by climate change.

The Ontario Forestry Institute got more specific in 2003. “Ontario’s mean annual temperature will increase by up to three degrees over the next century. Temperatures are expected to increase more in winter then summer with an increase in frost free days and to increase more in the north. Precipitation, although somewhat unpredictable, is expected to increase in Ontario, but increased evaporation and transpiration due to warmer temperatures will likely result in drier growing seasons.

Ontario’s Climate Change Research Report CCRR-05 states that people in much of southern Ontario, from Bruce Peninsula to the Ottawa Valley, will experience the types of hot summers that presently occur only in Windsor and Essex County. And, almost all of southern Ontario south of a line from Owen Sound to Pembroke will receive up to 10% less precipitation from April to September between 2011-2040. “Given precipitation is not expected to increase significantly; higher summer temperatures will potentially result in moisture stress affecting many aspects of life in Ontario, including reduced hydroelectric generation….”

That is the big picture of what is predicted for Ontario in the near future. Now here are a couple of specific changes we are already seeing.

Invasive Species
In the last 10 years, Canada has experienced 10 invasive forest pests. “The current threats posed by existing and potential invasive alien species are significant and are growing at an alarming rate,” says Canada’s Invasive Alien Strategy report. The most recent headliners are emerald ash borer, Asian long-horned beetle and the sirex woodwasp – and all in Ontario. Ontario has more invasives then the other provinces for two reasons. First, 70% of containers that arrive in Canada are opened in Ontario. Second, Ontario has more diversity of habitats and more tree species then anywhere else in Canada and thus provides the best chance for alien species survival.

Fifty percent of Toronto’s street trees are maple, one of the Asian long-horned beetle’s preferred hosts, and Canada’s maple syrup industry is worth $100 million annually. So the Asian long-horned beetle’s accidental discovery in September 2003 on the Toronto-Vaughan boundary started a chain reaction of discovery and eradication. Today, the area between Highway 27 West, Rutherford Road, Dufferin, and the 401 is regulated or continues under quarantine. Howard Stanley of CFIA says that people in the affected area have started to understand and accept the regulations. To date, 27,000 trees have been removed including 2,400 in 2007. Homeowners are encouraged to replant conifers, fruit trees or any tree not on the susceptible list and submit the bill for up to $300/tree that was removed.

Early predictions for the emerald ash borer when it arrived in Canada compared it to Dutch elm disease. Peter Sturdy of MNR explains, “When we remove one third of the trees in a forest, the whole complexity of the bush will change, and wind kill will be only one source of damage.” Today, EAB is the worst case scenario of an alien invasive species and we continue to learn new information every day. It attacks and kills saplings at only 1 cm but it also moves slower then originally believed. In fact, if humans didn’t move infected nursery stock or wood products, we wouldn’t have the same issue. But we still have no accurate means of detecting its presence until it is well established. Ken Marchant, CFIA, says they are currently attempting to quarantine Middlesex County and are hoping for parliament approval by Christmas 2007. Three paracitoids were released in the US this fall. If, and that is a big if, they are successful, the population of EAB could be controlled and ash trees will have an opportunity to develop resistance.

Lastly, sirex woodwasp is now widespread in southern Ontario but it isn’t the catastrophe expected from Australia’s experience. Monitoring is continuing.

Native Insects Stressed by Climate Change
Pine bark beetle in BC made headline news this year when researchers predicted it would travel from its native home in BC, where it is wrecking havoc, and move east across the boreal forest. In the past, pine bark beetle outbreaks were controlled by a sudden cold snap, but its range has increased substantially by global warming and the current outbreak has been prolonged by back-to-back warm winters. (It is expected to enter Alberta this year and there is nothing to stop its movement east until we get a “normal” winter.) Barry Lyons of Natural Resources Canada says it is unlikely to be a major threat to the boreal forest as there is minimal old growth, the preferred habitat of the mountain pine beetle in that habitat. Many argue whether the destruction caused by mountain pine beetles is the result of climate change or a forestry management issue but its ability to survive in the boreal forest at all is climate change.

Although a similar situation, the hickory crisis in southern Ontario didn’t receive a lot of media attention. It was confined to a small area and hickory is of low economic importance to the country as a whole, but our Canadian hickory bark beetle decimated old growth hickory forests after the 2001, 2002 and 2005 droughts. Today those forests are regenerating and are considered to be healthier and more diverse then before the infestation. MNR forest health technician Linda Tucker explains that nature is simply correcting itself.

Forest Fire
On average, 0.4% of managed forests burn in Ontario each year as part of their normal healthy cycles. Mike Flannigan, Canadian Forestry Centre, works on forest fire predictions. He states, “I believe that fire activity in Canada is already being influenced by human-caused climate change. However, there is a great deal of year-to-year variability. Next decade, I expect on average there will be about 10% more fires and 10% more area burned; by mid century, I predict approximately 50% more fires and twice as much area burned.”

Delivering more complete results then the old fire tower watch system and more efficient then the current helicopter spotting, Tim Lynham, also with the Canadian Forestry Centre, is investigating the other side of the concern. Working with the Canadian Space Agency (CSA), they are just delivering the third year of satellite fire maps and national estimates for carbon release. They are also supporting the CSA in the development of an infra-red detector scheduled for a NASA launch in 2010 to detect fires.

Rob Luik, MNR, gathers statistics for forest fires in Ontario. At the end of September 2007, we had 1,098 fires that burned 40,639 ha. This is significantly below the provincial average over the last 50 years of 1,603 fires burning 167,410 ha. Fire is a necessary part of Ontario’s ecosystem. It is neither good nor bad. Balancing when to allow natural fires and when to control them and when to use prescribed burns is a challenging task that is growing more complex with climate change.

Drought
Drought stresses existing trees and kills seedlings, but there is a secondary and potentially more serious issue. Barb Boysen of Forest Gene Conservation outlines the problem. In nature, every tree does not produce seed every year. This means growers incur the expense of holding over stock when they expect a shortage of seed the following year. Bumper seed crops used to occur on a regular cycle. Trees grown from bumper crop seed are hardier and grow faster then well-tended fertilized trees. For example, red pine produced bumper crop seeds about every seven years. In southern Ontario, our last bumper crop of red pine seed was 30 years ago and stocks are falling dangerously low. The good news is pine seed can be stored under proper conditions. Also the spring of 2007 showed an abundance of red pine pollen – the first sign of a bumper crop for 2008. There are many potential threats to this crop including infestation, animal consumption and/or drought causing trees to abort seed production. Let’s hope their effects are minimal. The bad news is most deciduous tree seeds can not be stored.

Tree seed and collection in Ontario has traditionally been a disorganized system of “mom and pop” low-income industries. Trees Ontario, a non-profit organization dedicated to increasing the number of trees planted in Ontario each year, is adding direction and management to the system with tree seed forecasting and tree seed collection training. The current theory is that for trees to thrive, the seed must be collected from the same region it will later be planted in. By organizing the collection, they hope to find small-localized pockets of bumper crop seeds and collect them at the correct time. Side issues noted in 2007 were the earlier hotter spring caused many trees to produce pollen during the spring rains. The pollen was washed to the ground without pollinating the flowers. Secondly, southern Ontario white pine cones opened two weeks earlier then expected due to the warm summer. Collectors were caught off guard and rodents consumed many of the seeds.

Early Detection
Finding a cheap and easy method of discovering where climate change problems are developing early is one of Tom Noland’s goals (Ontario Forestry Research Institute, ORFI). One method that looks promising is computer data collection from a satellite or plane. They expect they will be able to note changes in the trees before there is any visible damage by measuring bio indicators like the reflection of light from leaves or needles. Stressed trees show different reflection levels then healthy trees. We know maple, black spruce and the new needles of jack pine respond well to this test. While the test does not show why there is stress, it allows for screening of large areas and then ground crews can investigate specific locations.

Detection of defoliators like the spruce bud worm and the jack pine bud worm is excellent; however, since the emerald ash borer attacks healthy trees, it can’t be discovered with this screening program. The theory is to do routine screening to establish a base line of forest health and watch for trends.

Another area of interest to Tom Noland is protein studies. By extracting protein from trees, ORFI researchers are able to determine which proteins are associated with characteristics that are least susceptible to climate change and these trees can be propagated.

Endangered Species
We hear stress challenges endangered species moving them from endangered to expatriated quickly, but this isn’t always true. The endangered blue ash is surviving in EAB infested areas. In the quarantine lab in Sault St. Marie, yet another study is underway attempting to determine the levels of the active ingredient in blue ash compared to green ash that is discouraging EAB from attacking the former. The process involves cutting individual leaves of both blue and green ash, painting them with the measured levels of chemical, and allowing EAB to feed off the leaves, finally measuring to determine their preference. As the chemical is diluted steadily, they hope to determine the minimum effective level. This research will take years. Researchers in New Brunswick collect and save tree seed for all of Canada. But due to the drought in southern Ontario, they have been unable to obtain adequate samples of bumper crop blue ash seed from Ontario.

Conclusion
With all the stress and challenges that climate change brings, can we plant and maintain 30% forest cover in every municipality in the province? (The goal in many US cities is 40%.) The current state of forest says we have 107.48 million ha with 68.29 million ha forested and wooded land. Some basic math computes that 63% of our province is forested. 2001 saw a peak in the number of defoliated and beetle killed trees, while 1998 was a peak for area burned by forest fires in Canada.

Provincially, Ontario is in excellent shape, but data in southern Ontario is showing some worrisome trends – especially with the continuing loss of forested land to development. In a 2005 inventory, 60% of the city-owned trees in Hamilton’s north end were in poor or very poor condition. The GTA is listed at 19% forest cover with over one third of its trees in the threatened Oak Ridges Moraine. Oakville’s mayor believes they can pass the minimum and reach 40% urban forest cover by mid-century. They are currently at 29.1%. As on a global scale, there will be both winners and losers in the high stakes game of climate change in Ontario. It isn’t going to be easy for tree care specialists to meet climate change’s challenges but failure is not an option.

SIDEBAR #1

EAB Protection: Neem Injection

When the Canadian Forestry Service developed a program for injecting a natural product from the neem tree to protect ash from the emerald ash borer, everyone in the target area was positive about the idea. The Canadian Food Inspection Agency conducted surveys to establish which trees would be treated and which would be controls, but homeowners came forward and pleaded for protection for “their” trees. So, the researchers treated the survey chosen trees and as many of the requested trees as possible.

Neem is a natural product with antifungal, antibiotic and insecticide qualities from East India where it is has many uses including toothpaste and soap. A neem formulation was injected into ash trees in the infected area using the Ecoject System from BioForest similar to the way Dutch Elm Disease is treated. Of interest, it was noted that well mulched and watered urban trees received the injection readily within minutes. Drought stressed trees and those scarred by weed whackers and lawn mowers were a challenge and took several hours to receive the chemical because the drug is not “injected.” The tree draws the chemical in using passive uptake with transpiration. Neem can be injected at any time of year but the experiment was timed to coincide with the insect’s lifestyle, i.e. before the eggs were laid.

Ongoing monitoring continues to determine the latency period and if there is potential for soil or water contamination. Sticky tape was used to determine insect landing numbers and leaf and bark samples were collected to determine the viability of the chemical and the speed it is transferred through the trees. Early results indicate there is minimal residual azadirachtin, the active ingredient in the leaves, so it is unlikely to be an environmental concern.

SIDEBAR #2

Trial Forests: Provenance Testing for Climate Change

Steve D’eon of Natural Resources Canada (NRC) is studying the Petawawa forest. He is managing trial forests of 500,000 trees to determine how climate change will affect them. Working as part of a much larger cross Canada experiment, NRC has taken seed from the north and planted it in more southerly locations.

The provenance tests began in the 1960s and ‘70s measuring the growth rate of the trees. In one specific example, black spruce performed better when moved south and is expect to continue to excel as temperatures increase. Optimal growth was seen just north of the Canada/Minnesota border.

The models are not precise, so NRC can’t or don’t believe they should say exactly which trees should be planted in which regions for the best results. D’Eon says simply, “Broaden your bets for the future, don’t narrow the gene pool, and use the best seed available.” Climate change predictions, after all, are predictions.

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