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Outbreak in the North Woods UMaine partners with Maine Forest Service, Maine Forest Products Council for disaster preparedness in advance of the next spruce budworm infestation by Elyse Kahl
Mt Katahdin

Photo courtesy of David FieldIn 1980, Maine’s North Woods was a sea of gray, the result of a spruce budworm infestation that decimated millions of acres. This color photograph taken from the Knife Edge Trail on Mount Katahdin in 1980 shows the large area of trees killed by spruce budworm.

Maine’s Mount Katahdin is known for its challenging trails with rewarding, breathtaking views. On a clear summer day at Baxter Peak, the most northern point of the Appalachian Trail, hikers can take in all the natural beauty Maine has to offer — a green canopy dotted with cool, blue bodies of water as far as the eye can see.

In the late 1970s and early ’80s, that same view was a sea of gray, decimated by a relentless killer — the spruce budworm.

Larger moth image

Photo reproduced with the permission of the Minister of Natural Resources Canada, 2015.Adult spruce budworm moth Source: Trees, insects and diseases of Canada’s Forests, Spruce budworm fact sheets.

The eastern spruce budworm is believed to be the most damaging forest insect in Maine and North America. Outbreaks of the insect that kills balsam fir and spruce trees occur every 30 to 60 years.

And another one could be heading for Maine.

During the last outbreak, which lasted from 1970–85, the insect decimated up to 25 million cords of spruce-fir wood — 21 percent of all fir trees in the state, according to the Maine Forest Products Council. The infestation cost the state’s forest-based economy hundreds of millions of dollars and had lasting effects on Maine forest management.

Already severely damaging an area the size of Maine in southern Quebec, the spruce budworm is on track to begin defoliating trees in the Pine Tree State in the coming years.

In advance of the outbreak, the University of Maine has partnered with the Maine Forest Service and Maine Forest Products Council to form a Maine Spruce Budworm Task Force to keep forest landowners and government officials informed about the insect and aspects of Maine’s forest resources that would be affected by the next outbreak. The team also has created a disaster preparedness plan.

“Coming Spruce Budworm Outbreak: Initial Risk Assessment and Preparation & Response Recommendations for Maine’s Forestry Community” was released for public review in November 2014. The document was led by Maine Spruce Budworm Task Force leaders Robert Wagner, director of the Cooperative Forestry Research Unit (CFRU) at UMaine; Patrick Strauch, executive director of the Maine Forest Products Council; and Doug Denico, director of the Maine Forest Service.


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The report includes an assessment of the last outbreak and how to prepare for the coming flare-up using research and information from experts and landowners.

“Research since the last outbreak has contributed a lot to what we know today,” Wagner says. “What the budworm gave us last time is a better ability to respond this time.”

The spruce budworm is the immature stage of a gray-brown moth native to the northeastern United States and Canada. Numbers of the insect are often too low to detect, but every 30–60 years, the population explodes.

The exact mix of factors driving the insect’s episodic cycle in this part of its range are not known, Wagner says, but they include climatic conditions, other insects that feed on the budworm and availability of susceptible trees.

In Maine, the spruce budworm feeds primarily on the needles of balsam fir and white spruce, but also attacks black and red spruce, larch and hemlock, according to the Maine Forest Service. Heavily infested stands appear red in July due to dead needles on the branches. After several years of heavy feeding and two or three rounds of defoliation, the trees die.

The current outbreak has caused severe defoliation to about 15 million acres of spruce-fir forest in Quebec, according to the task force report. Northern Maine insect traps have captured increasing numbers of spruce budworm moths in the past several years, and defoliation of spruce-fir stands is approaching Maine’s northern border, the report states.

tree branch with water drop

“It’s like having a hurricane moving toward us from offshore,” says Wagner, the Henry W. Saunders Distinguished Professor in Forestry in UMaine’s School of Forest Resources. “We know it is there, how it behaves, and the kind of damage it can do. We can hope that it misses us, but if we don’t prepare for the worst — shame on us.”

At least six serious outbreaks have been recorded in 1770, 1806, 1878, 1910, 1949 and 1970–85, according to the Maine Forest Service. The 1910 outbreak devastated forests, but few people were living in the state, and the timber economy was small, Wagner says. Maine largely dodged a smaller outbreak during World War II in the 1940s and ’50s, which hit New Brunswick and prompted the use of DDT.

In the 1970–85 outbreak, spruce-fir was king in Maine’s forests, Wagner says. It was the primary feedstock for the state’s mills, with up to 70 percent of paper and solid wood products coming from spruce and fir. Concern grew with the loss of timber and the effect it would have on the future wood supply — and mills.

UMaine’s forestry department, established in 1903, has been through three spruce budworm cycles. Now a fourth is on the horizon. Many forestry students who graduated during the last outbreak built their careers on the effects of the budworm — from trying to control it to dealing with its aftermath.

John Bryant, regional manager for American Forest Management in Milford, Maine, earned a bachelor’s degree in forest utilization from the university in 1977. Early in his career, he learned how to manage a crisis and restore a healthy forest after a devastating insect infestation.

“I was a very young forester fresh out of college,” Bryant says. “The spruce budworm was feeding on red spruce, balsam fir and eastern hemlock trees, creating high levels of foliage damage and tree mortality. I vividly recall the brown and gray tops of trees, which were supposed to be green. And, the never-ending insects dropping from the trees, looking for more trees to eat.”

During the last outbreak, which lasted from 1970 until 1985, the insect decimated up to 25 millin cords of spruce-fir wood — 21 percent of all fir trees in the state.

Sources: CFRU, Maine Forest Service and Maine Forest Products Council

UMaine was viewed as a critical partner in helping the forest products industry cope with the last outbreak. In 1975, Fred Knight, former director of UMaine’s School of Forest Resources, established an industry-university cooperative to allow companies to pool resources and work together to solve problems through research.

“The budworm gave us the CFRU, which is a model of stakeholder-driven research with the people who own and manage the forest,” Wagner says.

As part of the cooperative, landowners — mostly large pulp and paper companies at the time — became part of a committee that strategized about UMaine research that would be most beneficial in the North Woods.

“The spruce budworm defined everything the CFRU did in the ’70s, and as we went into the ’80s, the budworm defined the forest. The cooperative’s research agenda evolved along with the forest,” Wagner says, noting that the group’s concerns changed from how to control the insect and understand its effects to managing the decimated forest.

CFRU’s focus on how to rapidly regenerate forests after the outbreak gave rise to research on vegetation management and seedling quality. Many of CFRU’s early studies led to some of the first herbicide research to control competing vegetation in the country, according to Wagner.

The research led to successful, widespread herbicide use in the 1980s and ’90s to regenerate the damaged forests. By the 1980s and ’90s, CFRU researchers began studying the budworm’s effects on wildlife and biodiversity as environmental concerns gained public attention.

The forest recovered and researchers turned their attention to vegetation management. Stands responded and were soon overstocked with spruce and fir. Research then switched to best practices in precommercial thinning.

There was a great deal of political pressure in the ’80s and ’90s about clear-cutting that resulted from harvesting trees killed by the spruce budworm, Wagner says, and the public controversy eventually led to the Forest Practices Act in 1989 to regulate clear-cutting. The act has gone on to define how much of the forest looks and is harvested today.

The current outbreak has severly defoliated about 15 million acres of spruce-fir forest in Quebec. Up to 5.8 million acres could be affected in Maine.

Sources: CFRU, Maine Forest Service and Maine Forest Products Council

By the late ’90s, the precommercial thinning had dissipated and the first stands became merchantable, Wagner says. In the new millenium, CFRU was helping landowners better understand commercial thinning, as well as researching the effects of forest management practices in the post-budworm forest on wildlife, including Canada lynx, moose, deer, songbirds and the northern long-eared bat.

“All those clear-cuts that created the controversy grew back into new forests that the forest products industry relies on today. Many of these stands are being commercially thinned now,” he says.

CFRU has a responsibility to help landowners deal with the coming outbreak and conduct new research, Wagner says.

“What makes me feel good about what we’re doing is that we have been having this conversation about the budworm for more than a year and we’re still two or more years away from having the first defoliated trees,” he says.

The long time span between outbreaks creates new challenges whenever the insect returns in full force.

“Every time the budworm comes back, there’s been enough evolution in the way people are using and managing the forest that it becomes a new event. A lot of the things we did last time are not relevant or aren’t acceptable based on today’s standards,” Wagner says, citing the heavy insecticide spraying and government funding used in the 1970s and ’80s.

The current outbreak in Quebec started in 2008 and has grown to affect more than 15 million acres in Canada, which is almost the same size as the state of Maine, Wagner says. The epicenter of the outbreak features moth flights so large they can be picked up by doppler radar. Moth flights toward Maine have already been seen on radar — technology that is helping researchers track and better understand these events.

The Maine Forest Service is monitoring pheromone traps to determine the change in moth populations around the state. Officials in New Brunswick also are using traps and comparing data with Maine. In 2010, New Brunswick began to see an increase in moth catches; two years later, Maine saw an increase, Wagner says.

“It’s an interesting phenomenon because there are native budworms in our forest, and the big question is: How much of the outbreak happens from the resident budworm populations exploding or from these waves of immigration?” Wagner says, adding that this is the first outbreak where technology exists to help answer that question, and a lot of research, particularly from the Canadian Forest Service, is looking at understanding some of the biological questions.

Pheromone trap in the forest

Charlene Donahue, a forest entomologist with the Maine Forest Service, checks spruce budworm pheromone traps in Old Town.

Pheromone trap sampling, which can be done by anyone and tracked using a mobile app, is an important part of the monitoring process. During the last outbreak, the idea of an early intervention strategy, or EIS, was born and monitoring is an essential part of the plan.

In 2014, the Canadian government awarded $18 million to explore an EIS, according to Canada Economic Development. Maine officials are working with their Canadian counterparts on the strategy being led in New Brunswick, Wagner says. In the 1970s, a similar Canadian-U.S. partnership was formed to focus on the budworm and other insects.

As the outbreak moves from Quebec into New Brunswick, Canadians are using traps to identify hot spots where populations are rapidly exploding. As part of the EIS, they are conducting insecticide treatments in small areas in hopes of suppressing the population explosion, according to Wagner.

He says there are several successful examples where intensive monitoring and small-scale insecticide applications were used to suppress the population of insects, such as the gypsy moth, to keep major outbreaks from starting.

“We think what happens is populations build to the point where they explode, and once they hit that threshold, there’s nothing you can do to deal with it, and that’s what happened in the ’70s outbreak,” Wagner says, adding that the monitoring efforts and biological understanding of the outbreak were unsophisticated by today’s standards.

Even with technological advances, there is no way to predict how the coming outbreak will compare to the last.

“It could be like the ’40s and be a little blip; not a big deal. Or we could see a wave that is almost as serious as the one that happened in the ’70s. It’s unclear,” Wagner says. “The one thing that is clear is that the outbreak in Quebec is quite serious. The center of that outbreak is as bad as it was in the ’70s. How badly, severely and broadly that moves out of that epicenter, nobody really knows.

Bryant says he thinks the outbreak will be less intense than the last.

“We will experience tree damage, but not to the extent of the last outbreak,” he predicts. “The forest is more diverse, fragmented, younger and healthier. We have more sophisticated tools to monitor, respond and access areas of high spruce budworm populations.”

Large landowners in northern Maine are likely to have some of the first properties in the state affected by the insect in 2016 or 2017. To prepare, they are looking into early intervention strategies that allow for treatments using aerial insecticides, according to Wagner.

The biological insecticides used today target the spruce budworm family and are unlike the broad-spectrum chemical insecticides that were used in the last outbreak. The bacterial insecticide Bacillus thuringiensis (Bt) is one of the only insecticides registered for organic farms.

Without a forest management response, the annual economic impact of the upcoming outbreak could reach $749 million.

Sources: CFRU, Maine Forest Service and Maine Forest Products Council

New Brunswick, which just completed its second year of targeted insecticide application as part of its EIS, has seen its first defoliated trees this year, Wagner says. That means defoliated trees in Maine are likely in about two years.

“Mainers should understand what’s going on in their forest,” he says. “Balsam fir forests around them may turn red and gray. It will change the scenery, it will affect the aesthetics of the forest and it could become a fire hazard.”

Wagner says residents, not just large landowners, should be concerned about the outbreak’s effect on the sustainable wood supply for northern Maine’s forest-based economy. Less wood to harvest could affect jobs, as well as have secondary economic effects in the community, including the Christmas tree and wreath industries, he says.

As CFRU director, Wagner often speaks with the directors of the Maine Forest Service and the Maine Forest Products Council, a political advocacy organization for the forest industry. The Maine Forest Service has a legislative responsibility to address forest health, and the Maine Forest Products Council represents the mills and landowners that will be affected by the outbreak.

“We knew we needed to get the parties that are going to have some kind of direct responsibility working together ahead of the outbreak, because we know from the last outbreak that when it starts, it can start very quickly,” Wagner says. “It’s like planning for a fire. You can’t do it while a fire is starting. You have to be ready to go because it happens so fast.”

Led by UMaine, the Spruce Budworm Task Force formed in 2013 to determine what economic and ecological effects an outbreak might have on the state, and what can be done to minimize those effects. The task force was divided into teams to look into specific areas. The teams brought together about 65 experts to contribute to the nearly 90-page assess-ment and preparation plan that focuses on wood supply and economic impacts; monitoring and protection; forest management; policy, regulatory and funding; wildlife habitat; communications and outreach; and research priorities.

Many of the senior foresters who contributed, including Bryant, were UMaine graduates whose careers were defined by the budworm, Wagner says.

Mainers should understand what’s going on in their forest. Balsam fir forests around them may turn red or gray. It will change the scenery, it will affect the aesthetics of the forest and it could become a fire hazard.”
Robert Wagner

“It’s a useful way for us to bring that historical voice,” Wagner says. “Many of our newly graduating forestry students will likely have their early career experiences formed by the next budworm outbreak, too.”

Creating the plan got forest landowners, mills, the government and university researchers talking with each other, Wagner says.

The beginning of the report is an assessment that includes original research conducted by CFRU, starting five years ago. Research includes a wood supply impact analysis conducted by CFRU, as well as an economic analysis conducted by UMaine economist Todd Gabe for the Maine Forest Products Council’s 2013 Maine’s Forest Economy report.

Robert Wagner in the Maine woods

Robert Wagner, director of UMaine’s Cooperative Forestry Research Unit and a leader of the Maine Spruce Budworm Task Force, stands among fir trees in the University Forest.

“We learned from the last outbreak that the budworm was a sociopolitical event,” Wagner says. “It’s not enough to have the government and landowners on the same page. We really need to get to the environmental groups in the state, the municipalities, the policymakers, the people who live in rural communities, the people that have camps in northern Maine.”

A draft of the report was released in November 2014. Task team leaders have presented the report to municipalities, environmental groups, the legislature, logging contractors and economic development consortiums. The task force report includes about 70 recommendations, several of which have already been implemented.

Wagner is now assembling the final report.

“We have a preparation plan. We’re waiting for this outbreak to unfold in the state. We’ve got a lot of the pieces in place and it will evolve,” Wagner says. “The report is not meant to be a blueprint for the future. A successful response will rely on good adaptive management.”

Bryant says he thinks Maine is more prepared for this outbreak because the state is already monitoring the insect’s movement, the forest is more accessible due to improved road systems, and foresters better understand the need to preempt the damage caused by the budworm.

The report’s recommendations on preparing for the outbreak include increasing monitoring efforts, judiciously applying insecticides where needed, changing forest management strategies such as harvesting, and seeking markets for presalvage trees that likely would be lost.

A severe outbreak could result in 1,196 jobs list annually in the forest products sector.

Sources: CFRU, Maine Forest Service and Maine Forest Products Council

“The key message: Don’t wait for the outbreak to properly manage the forest,” says Bryant, who led the forest management task team and was charged with developing guidelines for foresters to use in preparation for — and in response to — the coming outbreak.

A major concern for environmentalists is the use of insecticides and the effects on wildlife, which wasn’t as big of a worry 40 years ago. The question over who will pay for insecticide spraying — landowners or the government — already has started because of the report, Wagner says. The state and federal governments, which don’t have the available funds they did in the ’70s, have said if landowners want to treat their forests, it will be their responsibility. That gives landowners time to plan, which would not have happened if the conversation began during the outbreak.

An environmental and economic matter raised in the report is deer wintering, particularly those areas where spruce and fir trees provide a thermal cover for deer to stay warm during the winter months. These areas are likely to be severely damaged by the budworm, Wagner says. It is important to have conversations now about who will be responsible for protecting these areas, he says.

The report also includes research recommendations to increase understanding of budworm biology, monitoring, control and management. Short- and midterm research will be needed early in the outbreak to help forest managers respond. Longer-term research will inform those managing the next outbreak, likely to occur around 2055.

“Coming Spruce Budworm Outbreak: Initial Risk Assessment and Preparation & Response Recommendations for Maine’s Forestry Community” is available online.

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Fall/Winter 2015

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