Tired of fighting development on developers' terms, communities throughout Maryland have discovered a new weapon in the battle to preserve the state's dwindling supply of open space -- the land trust.

Fueled by incentives and seed money from the Maryland Environmental Trust and the state's Program Open Space, more than a dozen local land trusts have sprung up across Maryland over the past 18 months.

Faster than state preservation programs, more rooted in their communities and more vigilant by virtue of self-interest, the trusts have preserved more than 11,000 acres of land with little fanfare and less money.

"It's the hot thing," said Chris Rigby, director of the lands program of the Chesapeake Bay Foundation, which itself has formed a trust that is now preserving 3,604 acres.

"About 15 trusts have been incorporated recently. There were just two or three even two years ago," Rigby said.

H. Grant Dehart, director of the state-financed, 23-year-old Maryland Environmental Trust, said the trusts are becoming popular "because all these communities are seeing their favorite pieces of forest cut down for houses or for highways."

In one community it could be a stand of trees, in another a swath of rolling farmland, in yet another a shady stretch of shoreline. Whatever it is, the land usually is vulnerable to development.

"We were always fighting rear-guard actions. We wanted a plan that would let us take the initiative for once," said Gunther Wertheimer of the Mount Washington Preservation Trust in Baltimore, a new group that is looking to buy easements on properties as small as one acre.

The local trusts work by persuading their neighbors -- owners of open, scenic or environmentally valuable land -- to agree to give up development rights to the land, in whole or in part, by donating them to the trust.

Other tactics include outright purchase of the land, which is then donated to the trust, or financing its purchase with limited development on the least environmentally sensitive portion.

The legal term for such a procedure is a conservation easement, which is a legally binding contract that permanently restricts the way the land can be used by an owner or by a purchaser.

Donors often are longtime residents and farmers who don't want to see their land broken up after they die because of heavy estate taxes. Owners can get substantial federal and state tax breaks for deeding their land to a trust, along with a 15-year exemption from property taxes, and they get to continue living on and working the land.

Most conservation deeds even allow limited subdivision for the owner's heirs. But the deeds are permanent, and the community gets the assurance that the land never will be developed beyond its current use.

In Howard County, four landowners who live near the historic Belmont House -- now a conference center near Interstate 95 -- formed the Rockburn Morning Choice Historic Conservation District trust to conserve their 94 acres of land surrounded by Patapsco State Park.

Although deer often race across Belmont Landing road and the forest hides the four homes scattered throughout the tract, just across I-95 are acres of dense town house developments.

"I can't tell you how often developers were at my door offering me a fortune for my property," said William H. Servary, one of the landowners who formed the trust. The 73-year-old retiree, who moved onto his 23-acre sheep farm in 1964, resisted even in the face of seven-figure offers.

When neighbor Kevin Gaynor suggested that all the neighbors band together and keep their properties intact by forming their trust and donating their development rights, Servary said, "I began to feel I wasn't so crazy after all.

"I said, 'Should we let the children fight over the land and see it go for a development, or make them keep it for their future grandchildren to appreciate?' " Servary said.

"It won't become park, but now it cannot be sold for development purposes; it must remain a farm," he said. That is underscored by the deed of conservation easement, which prominently features words such as "irrevocably," "forever" and "unconditionally."

The Rockburn Morning Choice Historic Conservation District trust, in return, will monitor the land to make sure it retains its current character.

The tax breaks, said Gaynor, a lawyer, are "worth about 15 cents on the dollar what this land is worth. It is a financial sacrifice. But I've been looking for a place like this for 20 years, and I didn't want to see it spoiled."

Less certain, activists concede, are the benefits to the taxpaying public. The conservation deed takes the land off the tax rolls for a minimum of 15 years. Taxpayers, though, have no right of access to the land. Despite the easement, the land is still privately owned.