BERLIN - A man with an industrial-sized lawnmower - a "brush hog" - is leveling trees, clearing undergrowth, and cutting grass on conservation land in Berlin. But he's doing it to benefit, not harm, the indigenous wildlife.
In a counterintuitive measure practiced throughout Massachusetts, the mower is being used to selectively hack and slash the undeveloped area to cultivate a mix of open fields, scrub lands, and dense woods on the property. Rather than destroying habitat, experts say, the practice creates perfect conditions for deer, songbirds, and other animals.
The Berlin Conservation Commission is clearing part of a 15-acre parcel of former orchards at the intersection of Pleasant Street and Route 62 - land that the town had purchased four years ago for $550,000.
Already, 2 acres have been trimmed to resemble a lawn, ideal space for bluebirds and swallows to thrive, said commission member Walter Bickford. Next the commission is going to dig out invasive trees and bushes on a few more acres to free up space for native plants.
"This, here, is a European buckthorn," Bickford said, as he fingered a leaf while walking around the land recently. "It's an invasive, useless tree. It chokes out native species and doesn't help local animals. On the other hand, this is a glossy dogwood bush. These berries are good for the birds."
Over the next 10 years, said Bickford, the parcel should be divided equally between mowed open space, partially cleared areas, and land allowed to grow untouched. The varied landscape attracts animals that graze in grassy fields but like to run for cover, such as deer, as well as predators, such as coyotes, that hunt their fawns and other small animals, he said.
"You see where this grass is all matted?" said Bickford, pointing at tracks on the ground. "That's deer. This place is teeming with wildlife."
Suburban sprawl and the aging of the state's larger forests have resulted in the decline of what environmental experts call "early successional habitats," or areas where growing woods and open spaces exist alongside one another.
In the past, tornadoes, fires, and, most recently, farming cleared patches of forest to create these edge zones, said Thomas O'Shea, assistant director of wildlife at the Massachusetts Division of Fisheries and Wildlife's field headquarters in Westborough.
Today, said O'Shea, that process doesn't happen naturally. Forests gobbled up by suburban development don't grow back. Abandoned farms in areas like Berlin become overgrown, transformed from edge habitat into impenetrable brambles. Forests set aside by government or private conservation groups especially lack edge zones, because they often have been allowed to grow to be too dense.
Edge zones tend to border young woods. But the vast majority of the state's forests are between 30 and 150 years old, according to MassWildlife records. The situation threatens to create a monoculture, an environment that supports only a narrow slice of wildlife, said Andy Finton, director of conservation science at the Massachusetts chapter of the Nature Conservancy.
"Our forests are middle-aged," Finton said. "We're lacking the ends of the spectrum, the really old forests and the really young forests."
Most Massachusetts forests are the same age because they have been almost completely clear-cut twice, said O'Shea. The first time was hundreds of years ago, when agriculture was the backbone of the region's economy. "If you walked around in 1830, you'd see two-thirds of the state or more with open fields," he said.
Then, after farming in America moved west, the forests grew back. They were cut again, for timber, during the Industrial Revolution. The forests are now at a stage where they have recovered from that harvest, O'Shea said.
As the state's ecology has become more one-dimensional, edge habitat and its denizens are disappearing. "Songbirds, warblers, game birds, ruffed grouse, American woodcocks, have seen 2 to 3 percent declines per year," O'Shea said.
Finton said people have to step in, even if it means cutting down what seems like lush greenery. "These kinds of things are not pretty," he said. "A lot of forest management is not attractive to look at. But for biodiversity, it's what's needed. It's countering the homogenizing we see based on historical land use and forest management for the past couple centuries."
Of the state's 160,000 acres of state-owned wildlife management areas, around 1,000 have been 'edged' in the past 10 years, at a total cost of $1 million, said O'Shea. The division's goal is 10,000 acres, he said. Edge zones need to be remowed every six to 10 years at a cost of around $50 a year per acre. "People think after these areas are cleared, it's going to stay like that," he said. "They grow up quickly."
The custom takes a page from Native Americans, O'Shea said. "New England has had a history of human influence on our habitats for thousands of years," he said. "Native Americans were actually managing for some game species and managing for those scrub areas. Sometimes they kept the forests clear by burning repeatedly."
Bickford, a former commissioner of the state's Department of Fisheries, Wildlife, and Environmental Law Enforcement, acknowledged that some residents in Berlin may be concerned about additional deer living in town. The animals attract the ticks that carry Lyme disease and can cause traffic accidents. But Bickford said the town has plenty of capacity for more deer and other creatures.
"The majority of the population likes to see wildlife," he said. "It's just wonderful to see deer."