Rebirth of the American Beech: Selective Breeding Program Aims to Restore Healthy Beech to Maritime Forests

There was a time when American beech commanded much of the Maritimes, growing to tremendous sizes with porcelain smooth bark, a generous abundance of seed and autumn beauty to rival any hardwood. But that’s not the American beech we’ve come to know, seeing instead a tree corrupted by black rot, its bark twisted and cankered beyond recognition, stunted and with very few seeds. In little over a century this species fell from canopy heights, now a leper among plants.

The story of its decline, as told by ecologist Matthew Smith of Parks Canada, began in 1890, among the floral wonders of the Halifax Public Gardens. That year urbanites saw the addition of the European beech, either not noticing or not caring that the Beech scale, an insect endemic to the Old World, had come along for the ride.

This invasive, sap-sucking insect makes its living by puncturing the bark of European beech, but when it made the transition to American beech in 1890, the holes it left behind allowed the native fungus Neonectria to infect the tree’s compromised bark. Together insect and fungus swept across the Maritimes, progressing to this day across eastern North America to kill or disfigure a once proud hardwood. The ailment they cause is called Beech Bark Disease.

“The loss of beech has been pretty catastrophic for the Acadian forest,” said Smith. “I think people grow up seeing the American beech as a stunted and ugly member of our forests, but go to other parts of North America or Europe and you’ll still find beautiful beech. They’re incredible trees.”

PEI Beech Seed Orchard
Shown above is a seed orchard of disease resistant American beech growing in PEI National Park.
Zack Metcalfe photo

An Exceptional Few

Genetic diversity is a species’ best tool for survival and few exemplify this better than the American beech.

In the wake of the Beech Bark Disease an outstanding 3.3 per cent of Maritime beech remained unscathed, their bark smooth, white and heath as ever. Subsequent studies showed that, when the Beech scale inserted its feeding tube into the bark of these surviving trees, the insect died, some over a season, some almost immediately. The resistance mechanism allowing these trees to survive is poorly understood, but a quirk in their bark chemistry makes them lethal to the Beech scale, and thus safe from the disease it propagates.

Today Donnie McPhee is manager of the National Tree Seed Centre in Fredericton, NB, but in 2004 he was a forest genetics technician with the Canadian Forest Service (CFS). That year and the next he spearheaded surveys of 35 forest stands across the Maritimes in search of these resistant trees. The objective of himself and colleagues was to harness this natural resistance to found seed orchards, the products of which would be available for distribution across the Maritimes, an effort with two distinct parts.

The first was to take branches from under 100 disease resistant trees and “hot callous graft” them onto existing root systems in CFS greenhouses. These grafts, resistant in turn, were planted in three national parks in 2010 for safe keeping – Fundy, PEI and Kejimkujik. There they root to this day, only recently beginning to give seed.

The second aspect of this rescue was more scientific in scope. Taking the pollen of four resistant trees near Fredericton, McPhee and his colleagues began a series of controlled crosses – they paired two resistants, a resistant (pollen) and non-resistant (flower), a non-resistant (pollen) and resistant (flower), and finally two non-resistants as a control. The resulting seeds from each group, collectively numbering 1,000, were planted in 2004 and 2006 to see which pairing yielded the most resistant trees.

Once mature, these two groups of trees would set the stage for the concerted recovery of the American beech, the first offering resistant seeds in national parks, the second informing a future breeding regiment, but politics would prove as ready an obstacle as any invasive insect.

Endangered Funds

Under the Harper Government a great many cuts were made to biodiversity spending, up to and including efforts to breed resistant American beech. By 2011, the year after resistant grafts were planted in the aforementioned national parks, many of the Parks Canada employees overseeing them were let go, as were several of McPhee’s colleagues at the CFS. The products of their labours were relatively safe, but their workforce evaporated, fund disappeared and progress stopped.

Since then, the controlled crosses under McPhee’s care have suffered losses to hurricane winds and deer browsing. These setbacks and others have prevented them from reaching 5 centimetres in diametre, the width at which they can safely be declared resistant to Beech Bark Disease. It’s McPhee’s ambition to move them into a more secure location so the overall experiment can be salvaged.

“It’s been almost ten years since they’ve been outplanted,” he said. “If they were growing in ideal conditions from the start, in a field, say, they’d all be over five centimetres in diametre and five metres tall by now.”

Power of the People

“The breeding program really offers the best hope for restoring American beech to the forests of North America,” said Matthew Smith, himself active at Kejimkujik National Park.

The resistant beech grafts they received in 2010 numbered 99 in all, a few of whom didn’t survive the ordeal of planting but most stand strong in a portion of the park named Jakes Landing. Here they’ve reached the 5 centimetres in diametre necessary to prove their resistance to Beech Bark Disease, and prove it they have. Smith and his colleagues check on them frequently and are pleased to report their impressive growth, good health, perfect bark and newfound seeds.

These young trees are enclosed in a fence on an old stretch of farmland, growing without competition under Smith’s diligent protection. He said that while he’s supportive of distributing the beechnuts produced in this seed orchard, perhaps through Maritime nurseries, Parks Canada must wait for the initiative of the Canadian Forest Service.

“The long term plan would be to distribute as many of these beech trees as possible,” he said, but at the moment, these grafts and their seeds are subject to the Parks Canada motto – take only pictures, leave only footprints.

Donnie said that CFS must choose its projects carefully these days, given a lack of funding and staff after 2011. While he keeps company with researchers who would willingly continue the recovery of American beech, it would take an outspoken public, and a resulting swell of government support, to make this project happen. Given that the National Tree Seed Centre is actively preserving other threatened species, including ash, butternut and hemlock, he said such public support is most welcome.

“The problems just seem to keep coming up,” he said. “There seem to be more and more and more invasive species wreaking havoc on our environment. What it takes a lot of times for CFS to become involved in an issue is a public outcry. I think the public does have a role, albeit a small one, in directing where some research projects go.”

Zack Metcalfe is a freelance journalist, author, and writer active across the Maritimes. This article was originally published with Atlantic Forestry Review.

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