An Ounce of Prevention - How The History of DED is Affecting Arboriculture in Ontario (Focus on EAB)

July-August 2010

SOME INDIVIDUALS AND MUNICIPALITIES across Canada in different situations with different opinions and different budgets scrambled to preserve Canada’s tree heritage when Dutch elm disease (DED) struck. Other municipalities gave up or did nothing, losing the many benefits of the mature elm in their areas. Now armed with a strong history of DED management and knowledge, we are making similar decisions regarding ash and the emerald ash borer (EAB). And take note, as Dr. Les Magasi of New Brunswick said, “Disaster is not inevitable.”

Over fifty years ago, the beautiful city of Fredericton, New Brunswick, with its monoculture of majestic elms, had a looming crisis. Dutch elm disease was decimating elms in North America and appeared unstoppable. Today, Fredericton continues to uphold their motto of Clean and Green. The elm many gave up on is continuing to thrive and “work” for the city but it wasn’t easy and many wanted to give up along the way.

Nine years before DED entered Fredericton, a group of citizens recognized the devastation potentially heading their way. Looking around the city, they saw the benefits of the elm – especially after travelling and viewing the almost complete loss of elms in hard hit areas. Stirred to action, a tree commission was established and they went to work. Over 500 elms were cut. Many more were pruned, and most importantly according to Dr. Les Magasi, now the longest serving member of the tree commission, they established bylaws allowing city personnel to enter private property, inspect and remove diseased trees. This was all free of charge to the landowner.

In 1961, when DED was finally discovered in Fredericton, there was no panic. They were ready for battle. “Beetles don’t know property lines,” says Magasi. “For a control program to work, you have to deal with both public and privately owned trees.”

Don Murray, city forester in Fredericton and ISA member, says they now consider DED a reoccurring urban pest. “We are planting white elm again! “When I graduated, many wondered why I would want to work for Fredericton when there is money to be made in industry. Today, graduates come to me looking for work. I have a good pension and steady work.” Murray’s voice escalates with enthusiasm as he adds, “We have a well trained staff. We’re current. I have the best trained people in pruning with almost a million dollars in equipment. We take pride in our city being Clean and Green.”

Dr. Magasi emphasizes that it wasn’t an easy road from a monoculture to an arborists dream. Don Murray lists many other Maritime cities that faced with the same crisis started well but didn’t continue and their DED programs died. He says the difference in Fredericton is the Tree Commission. “This is not a lobby group. They give advice. If counsel says no, they accept it. They do not start public campaigns. Counsel respects the Tree Commission. Mayor after mayor and their council support is passed down. Our commission is all volunteers from a variety of backgrounds including specialists in tree management and media experts (and Dr. Magasi’s advice is priceless). We rarely hear ‘no’ from council. Tree care doesn’t work unless it is publicly funded. If you lose support for one year when you are fighting an invasive pest, you lose it all.”

Dr. Magasi reflects on their success differently. He clearly recalls years when DED was on the increase and people were saying they were wasting their money. Between 1976 and 1980, the situation looked pretty dire. The city lost 20% of its elms while outside city limits, 95% of the elm died. “The city was a green island of trees. We tried everything. We clear cut. We tried injections, but we were really fighting the doubters.”

Magasi continued, “We had to be dedicated to the program. We did things to demonstrate to the public the need for elms. We went to a street corner with two elms on one side and none on the other. We took the temperature during the day. There was a twenty degree differential. We asked them where they wanted their children to play. People understood. We succeeded because we stuck with the program even when it looked grim. Disaster is not inevitable.”

“In 1981,” said Magasi, “we saw the first decrease in DED losses. After that the graph was so perfect I was accused of cooking the books. I say it costs one penny per day per citizen to save the elm long enough to convert the urban forest to diversity. We lost 30% in 30 years compared to areas that did nothing and lost 95% in eight years.

How has experience with DED affected expectations and treatment of EAB?
Dr. Magasi and Don Murray may express issues differently and offer independent opinions, but they are united in their goals and work. They both agree that working together and respecting each other is a big part of their success.

Murray says Fredericton is a growing city. New residents have no memory or loyalty to the elm. “People don’t know we prune 7,000 trees each year. It’s up to us to go to the citizens and explain what and why we do what we do. They look to us as a resource. It raises our credibility in the city. We consider EAB and Asian longhorn are just one day away. We’re promoting “Burn it where you buy it.” We won’t back down. We will do everything in our power. We stopped planting ash. If it arrives, we know what we will do.”

Magasi’s answer reflects Murray’s last statement. “Because we fought DED we have a tree commission, a trained staff, a program, and a plan. We are holding public meetings to educate the general public. Citizens need to know we can’t have a watchful eye everywhere.”

Fredericton’s budget for tree care is a quarter million per year. Previously, they spent 75% of there time on elm but this was recently reversed so they now spend 75% of their time on the rest of the urban forest.
What if Fredericton had done nothing? Magasi replies, “The dead elms would still have to be removed and there would be no benefit.” Murray says, “By fighting back, we allowed science time to catch up with hybrids and disease resistant trees.”

The Sault’s DED Story
In Ontario, the situation was different when DED threatened Sault Ste. Marie. The Sault, as it is affectionately called, is also home to a Natural Resources Canada forestry centre. It is a relatively small city with limited funds. However, as the disease threatened, because the city was not a monoculture and there was not the same level of public interest, the same emphasis seen in New Brunswick was not placed on tree management.

Don D’zama is supervisor of forestry in the Sault. He’s been an arborist for 32 years. He says from the sixties through the nineties they maintained a program of sanitation and injection on both privately owned and city trees. As a direct result, the Sault maintained a large number of mature healthy elms. But then came funding cuts, and provincial and bylaw changes.

DED entered the Sault around 1968 and sanitation started in 1971. With the funding cuts they recognized the loss of elm was inevitable and they stopped planting elm in the 1990s. Today the Sault only removes dead elms on city property. The budget is about $20,000 per year for elm. They do not enter private lands. They do not practice sanitation for DED. They did identify one hundred stately elms and these are injected as per protocol. They have noted a loss of mature elm and regeneration.

Tony Hopkins is at Natural Resources Canada in Sault Ste Marie. He emphasizes the importance of control and sanitation in the protection against DED. He understands the frustration of a small city and the costs involved with a tree care program. “Our laboratory is a significant resource in the city. We give the best advice we can but we don’t have the mandate or funds to manage their urban forest. We provide management plans and the new one for identifying EAB infested trees should be out soon.

How has experience with DED affected expectations and treatment of EAB?
D’Zama says, “EAB entered the Sault two years ago and we stopped planting ash at that time. The downtown core is a monoculture of ash – I just got those trees to a mature canopy over the street.” His voice is low and discouraged. “We’ve never won against an insect. The hybrids and disease resistant elm we had are now being attacked differently. The ash we injected last year don’t look good. We will get the survey results next week. We are suspecting it is our colder climate. The timing might be the issue but we may have to inject annually. Spruce budworm is attacking the north end of the city for the third year in a row. Many of the spruce are done.”

He continues: “Our budget is $25,000 for ash and tax increases don’t go over well. Here in northern Ontario everyone thinks we have an over abundance of trees. They go out of the city and see no houses, just trees. We have no tree protection bylaw. Tree concerns are always getting shut down. It is hard to even protect trees on city property. People get tired of raking one year and they cut down the tree. They don’t see any reason to panic while in the arboriculture industry, we can see a crisis is coming. I would have to start over completely in the downtown. I believe you shouldn’t take a tree down unless it is dead. Move your driveway! But the public doesn’t see it that way.”

Hopkins, Natural Resources Canada, said, “With different invasive pests there are similarities in the management plans.” So if you have one management plan it is easier to implement the second. “The big issue is preventing invasives from entering the country in the first place. We have an international agreement on wood packaging. So often when these insects are discovered little is known about them in their home country. They usually aren’t a problem where they have natural predators. On the flip side, sometimes insects we predict to be a problem are not.”

Hopkins advises: “Your shade trees are a valuable resource. If you don’t invest in prevention you will have an expensive bill to replant as urban dwellers will demand trees. It is the frontline workers who provide detection.”

Moving West
In Winnipeg, Manitoba, a battle was also waged against DED. Martha Barwinsky has a Master of Science and is the city forester. She says before DED arrived in Winnipeg, they already had seen its impact on other areas. The Province of Manitoba started its DED program in the late 1960s. The disease didn’t strike until 1975. The City of Winnipeg is maintaining the largest urban elm population in all of North America with an annual budget of $3.68 million (one million is from the province.)

Barwinsky said, “Elm is our best urban tree. It is tolerant to our urban conditions and climate and is indigenous, a good overall tree. We are planting elm. We are also involved in testing for hardiness on the disease resistant cultivars. We don’t know if they can survive our climate yet. We have about 155,000 elm left standing in a full range of sizes. At our peak, before DED, we had about 280,000.”

“We are partnering with the University of Manitoba and the province on research on the native elm bark beetle and the banded elm bark beetle in Manitoba. The U of M is studying their life cycles and behaviours, including their impact as vectors for DED and how we can better manage them.

How has experience with DED affected expectations and treatment of EAB?
Barwinsky said, “We have more ash then elm. We estimate we have 280,000 ash. EAB will definitely be a greater challenge. We are at high risk of losing a significant part of our urban forest. We have a strong track record of successfully managing DED and are hopeful we will get the support we need to battle EAB. We know that, especially with EAB on our doorstep, managing DED and maintaining our great canopy of elms has been worth it.”

“The new provincial Forest Health Protection Act will help us more in managing DED but also will help us deal with EAB. We have stronger authority for enforcing such things as prohibiting transportation and storage of firewood. With DED, we conduct elm firewood surveys and ask home owners to dispose of the wood. In general, we have pretty good compliance, but as time goes on, compliance is decreasing as complacency tends to set in. We have the authority to go on private property, remove firewood, and charge it to the property owner, if we have to take that route.”

“Winnipeger’s put a high value on their urban forest. The group Trees Winnipeg got a lot of community action going – especially in the early days of DED.”

“We have a complete DED program with surveillance, sanitation, pruning, vector control and public education. If you drop just one element, the whole program falls apart. Public education can’t be stressed enough. Eighty percent of the diseased trees are on private property. People get really upset when a diseased tree comes down. We couldn’t live in Winnipeg without the urban forest and must foster appreciation for it.”

“For EAB, we started awareness and education a few years ago within the green industry and with the general public through the media. People are already watching and concerned. We have developed a preparedness and response plan and have started preventative measures. We have trained our staff to monitor for EAB. This year, we will have signage about the risk of moving and storing firewood. We are working with CFIA and the province to install traps in the city. We aren’t testing TreeAzin but we are watching its effect in Ontario.

In summary, we’ve examined DED and EAB strategies in three jurisdictions across the country. The bottom line appears basic: tree management plans need to be adapted to reflect the personality, budget and needs of each municipality. When arborists stand together and work with our governments and involve the general public, “Disaster is not inevitable.”

Sidebar 1: Dutch Trig's Debut in Canada

People who should know how Dutch elm disease works and can be treated, often still don’t seem to know,” says Philip van Wassenaer of Urban Forest Innovative Solutions. Urban Forest is the Canadian distributor for the newly registered preventative Dutch Trig. Van Wassenaer doesn’t pretend or suggest this micro injection is the cure-all for every elm. Rather he suggests it should be part of a complete DED program that includes monitoring, pruning and even fungicides. “It is a preventative, not a curative. It will not protect a tree that is already infected.”

Dutch Trig was injected into 2,000 Canadian trees this spring. All will be monitored to determine if the Canadian rates come close or match the over 99% success seen in the Netherlands. In fact, van Wassenaer claims that in The Hague they have 35,000 elms and one third are injected annually with Dutch Trig. Before the preventative was used, they had an 8-9% infection rate among their elm tree population. After they started using Dutch Trig, the rates of loss in the non-injected trees dropped as well to around 4%. He says the preventative may have literally reduced the infection rates across the city.

Here in Canada, our only test over one year-old is in Winnipeg. City Forester Martha Barwinsky says, “We are cautiously optimistic but can’t formulate a solid opinion until we have tested it for a few years. I believe it may be best applied in a residential setting where a homeowner has a mature, healthy elm of great value. The product is quick, safe and easy to use, though there is a very small window of time in spring to apply it (during leafing out stage up to 75% leaf expansion and ideally before the elm bark beetle starts feeding in the canopy) and it should be applied only by a qualified arborist/pesticide applicator.”

Van Wassenaer says of the 202 trees injected in Winnipeg’s first treatment year, five developed DED. Samples from these five were sent to an independent laboratory and all were found to have been infected prior to the injection.

The residential sector in Winnipeg isn’t waiting to see if Dutch Trig works under their conditions; 800 plus trees were injected on private land this season. Phil van Wassenaer says this was a difficult year to market since the registration came so late in 2009. They expect to double sales next year.

In Fredericton, one large tree was injected with Dutch Trig as a demonstration. Don Murray says, “The cornerstone of Fredericton’s DED program has been sanitation. We still have elm trees that are from the 1880’s plantings and many elm trees from the early 1950’s plantings. Sanitation is expensive as it is labour and equipment intensive. Fredericton did inject trees with different chemicals on a trial basis and also used trap trees and whole tree spraying for beetle control. Other communities during the same time period put their funds towards injections and today they have few, if any, white elm trees left. Fredericton is fortunate in that we have our own arboriculture staff and consistent yearly funding for a tree program. Our sanitation program is working. The incidence of DED is not rising but I do recognize it as a cyclic pest and I fully expect that we will see DED numbers increase once again as new elms in outlying areas grow and are infected with DED. Bark beetle populations will rise in the outlying areas and then move into Fredericton and infect elm trees within city limits. At that point sanitation will once again prove its effectiveness.”

When asked directly if Fredericton will use Dutch Trig, Don replied: “We will not be giving up sanitation as the method of controlling DED. If budgets permit, we would consider injecting a few of our older elm trees that are located in the historic centre of the city with Dutch Trig. We will not relax our sanitation program to fund a full scale injection program. We will be watching for success stories from other communities and always evaluate new methods of DED control. Lastly, we will be planting DED tolerant varieties of white elm.”

Sidebar 2: The Ontario Government Weighs In
Interview With MNR's Jolanta Kowalski

Q: Some have criticized the Ontario government saying municipalities are the highest level of government fighting EAB. How do you respond?

A: The Ministry of Natural Resources (MNR) is very concerned about the spread and impact of the emerald ash borer in Ontario but the Canadian Food Inspection Agency (CFIA) has legislated responsibility and is the lead for dealing with invasive forest insects such as the emerald ash borer. MNR has focused its efforts on research to develop methods for finding new infestations and the search for parasites to provide long-term control. 

Q: Why do municipalities not get provincial funding for invasives in Ontario when other places like Winnipeg get a million a year from Manitoba?

A: MNR did have a program in the 1980s and early 1990s which provided assistance to municipalities to control gypsy moth. This program was ended in 1992 for financial reasons. Since then, the ministry’s view is management of trees and forests on private land is the responsibility of the landowner. This is similar to native pests, windstorms, and other things that may affect tree health. MNR did provide $1 million in funding split between Essex County and Toronto for re-greening areas affected by emerald ash borer and Asian long-horned beetle. This funding was in response to the need to rehabilitate the areas after CFIA had cut and chipped trees.

The Manitoba funding is through a cost-sharing arrangement with the city of Winnipeg to combat Dutch elm disease. Unlike Manitoba, Ontario has several other invasive tree pests (e.g., gypsy moth, butternut canker, beech bark disease, sirex woodwasp, pine shoot beetle, chestnut blight) which would be very expensive for the province to try to manage on private land.

Q: There is also the accusation that the province is not providing leadership in the fight against EAB. Can you respond? How are you or why not?  

A: The Ministry of Natural Resources has focused its efforts on research to develop methods for finding new infestations and the search for parasites to provide long-term control:

MNR and Canadian Forest Service (CFS) staff made the original discovery of EAB in Canada as part of the forest health program conducted by the two agencies. Since then the province has continued to look for EAB, which has resulted in finding the beetle just outside London at Dutton, and in the city of Toronto. MNR has also conducted aerial surveys to assess the impact of EAB on the forest in southwestern Ontario.

In November 2009, MNR together with the CFIA and CFS, hosted a workshop Guiding Principles for Managing the Emerald Ash Borer in Urban Environments, which had over 100 participants. Many of the participants were urban foresters and arborists. Town of Oakville Forestry Services Manager John McNeil was featured as one of the speakers.

During the winter of 2009-10, two field technicians from MNR’s forest health program worked with Oakville and the Canadian Forest Service to field test and collect data on the use of a new branch sampling method developed by the CFS to find emerald ash borer and determine which trees are infested.

In 2010, MNR staff are working with the Canadian Food Inspection Agency to carry out surveys to detect new infestations. In 2009, MNR conducted surveys at high risk sites (e.g., campgrounds)

MNR is also supporting research by the Canadian Forest Service to determine the impacts of this insect on our forest ecosystems, and to develop new survey tools to find infestations as early as possible. MNR is collaborating on and providing funding for a project with the CFS and the University of Toronto to evaluate the role of native parasites in the long-term biocontrol of emerald ash borer.

In 2008, 2009 and 2010, on behalf of CFIA and CFS, MNR successfully obtained an emergency registration of TreeAzin insecticide for protecting high value ash trees. TreeAzin, which is derived from the neem tree of India and injected in ash trees, was developed by CFS.

Our government continues to work with the federal government regarding the establishment of a Canada-Ontario Invasive Species Centre in Sault Ste. Marie.

Our mission is to enhance and promote the care and benefit of trees for present and future generations in Ontario through education, research and awareness.