How the mighty are falling
Insects and fungi are ravaging oaks in Southeastern Mass., creating a costly cleanup
FREETOWN - Victims of the silent insects that gnawed for years on the state's forests litter the yards and streets of this community, once lush with leafy oaks that are now bare and dead.
Some remain standing, limbs stiff and brittle, looming over power lines and houses below. Others lay stripped and stacked on the side of the road, waiting to be chopped for firewood or hauled away.
"We moved here two years ago in November, just assuming the trees had passed for the season," said Alissa Miller, 30, whose small house is framed by two dead oaks arching over the street. "The first year they didn't bloom and we didn't think much of it. Then the branches started falling, and we're like, 'Oh, I guess they're dead.' "
Investigators estimate tens of thousands of oak trees in Southeastern Massachusetts have died during the past three years, a result of leaf-eating caterpillars and opportunistic beetles and fungi. The suspects have since subsided, leaving residents, towns, and utility companies with the costly task of tree removal.
"It's like we had a hurricane but all the trees are standing, and now we have to deal with them," said Gary Loranger, tree warden in Freetown. "It's going to lead to trees falling in storms across the roads, and possibly catastrophic situations."
Loranger said his department has spent $60,000 since 2006 to take down the dead trees, but a tight budget this year has curtailed the efforts. Officials in Wareham said they are scrambling to fund the removal of about 200 dead trees before winter, when they could crumble under the weight of snow. And even the well-funded tree program in Duxbury was allotted an additional $40,000 this year to deal with the dead oaks, said Peter Buttkus, the town's director of public works.
"We had about 300 trees on our list for removal," Buttkus said. "We normally have about a dozen."
Large outbreaks of gypsy moth, winter moth, and forest tent caterpillars began in 2004. Two years later, the combined attacks of all three leaf-munching critters left nearly 600,000 acres of Massachusetts' woodland bare and vulnerable, according to a report by Charles M. Burnham, supervisor of the state's forest health program. The insects subsided in 2007, and preliminary reports show they remain on the decline this year, Burnham said in a phone interview.
But the impact of the infestation remains. As caterpillars eat the leaves, the tree responds by attempting to grow a second set of greens in the same season, Burnham said. But repeated defoliations severely weakened trees and made them targets of secondary invaders.
"Trees produce natural defenses that deter certain insects," said Robert D. Childs, entomologist at the University of Massachusetts at Amherst. "But once the tree's defenses go down, the insects move right in."
A small, black beetle known as the two-lined chestnut borer knows exactly when an oak is struggling. No more than a quarter-inch long, the adult borer lays eggs under the bark. When the eggs hatch, the larvae act like a tourniquet, feeding on the tree's nutrients and preventing them from reaching the rest of the plant.
But the beetles didn't work alone. A fungus known commonly as shoestring root rot infiltrated vulnerable trees' bases and prevented them from absorbing moisture and nutrients. Its calling card: black, string-like strands that can often be seen between the bark and the wood, on the surface of the roots, or in the soil.
"These things are in nature all the time," Childs said. "But when there's a land of plenty, then it's a feast."
But a big meal requires a big cleanup, which falls in part to Paul Sellers, senior arborist for
"If we take an outage on a line like these, we're likely to see several hundred customers without power," Sellers said. NStar estimates that oak tree removal in Southeastern Massachusetts will cost about $750,000 during the next three years, said Caroline Allen, a company spokeswoman.
Town and state agencies will be responsible for roadside trees, which threaten motorists and pedestrians passing below. But the rest are the problem of homeowners, many struggling in the country's economic downturn. The average cost of removing a tree runs between $500 and $800, said Loranger, owner of Beaver Tree Work in Lakeville.
An empty swing hangs from the dead limb of one of several oaks surrounding Eliza Robillard's house in Freetown. Her son once played in the shade of its leaves, but now the dead tree lingers just feet from her back door. Soon it will tumble at the hands of private contractors.
"It's really sad to see it go," Robillard said. But she won't plant anything in its place. "Not oaks, anyway."
Christopher Baxter can be reached at cbaxter@globe.com. 