More land saved than developed, study finds

Through the 1990s and the early part of this decade, forests and fields were being developed - mostly into new home sites - at the rate of about 40 acres a day. In recent years, the study shows, that number was cut nearly in half, to about 22 acres a day.

At the same time, conservation efforts have stepped up, so that each day 43 acres of land are protected as open space, usually through legal agreements with private owners or purchases by conservation groups or the state.

"The good news is we are no longer gobbling up open spaces," said Jack Clarke, director of public policy and government relations for the Massachusetts Audubon Society.

The slowed pace of development probably has more to do with flat population growth - and more recently the recession - than dramatic changes in zoning and other laws limiting home construction, officials say.

The exhaustive Mass Audubon study is one in a series done about every five years. It is based in large part on state data and aerial photos, and analyzes land use from 1999 through 2005. But Mass Audubon of ficials say the recent falloff in home construction has extended, and amplified, development cutbacks to the present day.

This window of slowed development, Mass Audubon officials say, provides the state an unusual opportunity to reset zoning laws to further protect vulnerable and ecologically important lands, such as pitch pine and scrub oak barrens in the Southeast, and enormous tracts of forest in the western part of the state, where development is headed.

While the report is encouraging, said Clarke, "this is also a red flag to some places - get ready" for development.

The study shows that as construction intensifies in many parts of Central and Southeast Massachusetts, the front line of development is pushing its way into forest and farm lands near the Quabbin Reservoir, along the Connecticut River, and even in a part of the Berkshires.

And although many Bay Staters are adopting greener habits, they continue to build larger and larger homes - from 2,260 square feet on average in 2001 to 2,700 square feet today. In 1970, the average house size was 1,572 square feet.

Those enormous homes, Mass Audubon officials say, release more global warming pollution and have a larger effect on nature. For example, the scarlet tanager bird, which lives in forest interiors, is likely to disappear in places where housing lots fragment large tracts of woods.

"We call our brand of sprawl 'sinister sprawl' because it is a horizontal ooze that spills out of the Pioneer and Connecticut River Valley to [eat up] the most prime agricultural lands," said Timothy W. Brennan, executive director of the Pioneer Valley Planning Commission. "We are growing subdivisions on larger and larger lot sizes."

Two years in the making, the land-use report is the fourth in a series titled "Losing Ground."

Mass Audubon's last report served as a wake-up call to many environmental officials and conservation groups to ramp up land protection efforts. And between 1999 and 2005, some 109,863 acres of public and private lands were protected through purchase or conservation easements, which allows some recreational or forest activity but no development. Governor Deval Patrick's administration is committed to land preservation with a promise, now in its second year, to spend $50 million a year on protection, according to administration officials.

"Mass Audubon continues to draw attention to a serious challenge," said state Energy and Environmental Affairs Secretary Ian Bowles, in an e-mail. The state's highest land preservation priorities, he said, are "urban parks, working landscapes, and valuable habitat."

The new study identifies "sprawl frontiers" where development is the most rapid - including a top 20 list of fastest growing towns, with North Attleborough, Norwell, Hanover, Berkley, and Somerset topping the list. It also flags "sprawl danger zones" - a large chunk of Central Massachusetts and along the Connecticut River - where development is increasing but significant land is also available for conservation. Even a part of the Berkshires is included as a danger zone, probably because of increased housing construction from second-home buyers.

Mass Audubon officials - and building associations - say zoning changes are critical to protecting land. Today, many communities require 1- or 2-acre lots for new homes, zoning designed years ago in part to preserve a community's rural character.

"But it has had the opposite effect - it sprawls out and destroys," said Clarke.

Diana Pisciotta, a spokeswoman for the Home Builders Association of Massachusetts, says large-lot zoning has the perverse effect of driving up housing costs in the Commonwealth because land is so expensive. When developers are forced to build a home on a large lot, they build a larger home to recoup their costs.

"People won't pay for land. They will pay for a house," said Pisciotta.

The Mass Audubon study also highlights a new way of looking at land, through a lens of ecological impact. The conservation group and University of Massachusetts at Amherst researchers are examining less direct effects, such as what species will leave - or come to - an area of land because of new home construction.

Beth Daley can be reached by email at bdaley@globe.com

Information about specific communities can be found at www.massaudubon.org/losingground.