MEDFORD - With a single snip of a pair of long-handled clippers, Peter Luongo ended the life of a spindly sapling poking up through the snow at the Middlesex Fells Reservation.
Killing trees isn't among the obvious duties of a park ranger. But Luongo and a group of volunteers are clearing saplings and brush once a month this winter in a small section of this more than 2,000-acre nature preserve that straddles the borders of Medford, Winchester, Stoneham, Melrose, and Malden.
"What we're trying to do artificially here is turn back the clock," Luongo said. "With global warming, you hate to cut down trees. But I don't really feel bad here because this historically was a meadow."
Their efforts are a solution to a somewhat counterintuitive problem in many parts of New England: Woods have replaced open pastures and farmland to such an extent that some wildlife dependent on such areas no longer have a habitat to call home.
Bobolinks are songbirds that require open pastures for their ground-level nests. Sharp-shinned hawks and foxes eat voles that burrow under meadow grasses. Even deer prefer forest edges, savoring the tender green shoots of young trees and the open horizon for spotting predators.
"Since New England went from forest to farmland, we lost a lot of forest wildlife," said Michael Arnott, who helps coordinate the meadow clearing workdays for the nonprofit Friends of the Middlesex Fells. "And now we've almost gone too far in the opposite direction."
In the mid-19th century, two-thirds of southern New England land was clear, opened for the pastures and crops needed in the agricultural-based society, said John O'Keefe, coordinator of the Fisher Museum at Harvard Forest in Petersham, where the museum's dioramas depict more than 300 years of the area's changing landscape.
Then, the industrial age shifted jobs away from farms. Woods returned. By the 1970s, forests covered two-thirds of the land again. "It had completely flipped," O'Keefe said.
Now environmentalists, birders, and hunters are looking for more mixed habitats in the areas that haven't already been developed. For at least 10 years, governmental and nonprofit groups have been trying to encourage the preservation - or, in some cases, restoration - of grasslands around New England to recreate some of the habitat needed for birds, butterflies, and native plants.
This summer a 10-year program began in Belmont, where a federal grant is helping to restore about 30 acres at Rock Meadow conservation area.
And at the Fells, volunteer crews are clearing the brush from a less than 20-acre overgrown field that was an antiaircraft military site in the 1950s near the Winchester/Medford line. Some locals call the area the
Even after the Nike ended up at another locale and the battery was abandoned, the area remained an open field.
For years, the former Metropolitan District Commission mowed it, keeping sprouts from growing into saplings, then into trees.
It became an area rich in butterflies, with 67 species recorded there between the late 1960s and early 1980s, including the rare oak hairstreak, also known as the northern hairstreak.
But the mowing stopped. Since then, trees and vines - especially invasive species such as Asiatic bittersweet - have taken hold.
The clearing project began last year on winter weekends. The cold and snow means no ticks, Arnott said. Poison ivy lies leafless and tamed under the snow.
Kytja Weir can be reached at firstname.lastname@example.org.
The next Friends of the Middlesex Fells meadow restoration workday will be 10 a.m. to 2 p.m., Jan. 26. Volunteers must preregister by calling or e-mailing the Friends office at 781-662-2340 or email@example.com.