WESTBROOK – U.S. Sen. Susan Collins, who says tens of thousands of acres of forests have been lost to sprawl in Maine, has introduced a bill to stop sprawl by protecting working forests.

Southern Maine’s working forests are disappearing because land is more valuable as house lots than woodlots. The amount of urbanized land in southern Maine has doubled over the past 20 years, she said.

“This is a new threat to Maine’s forest that requires a new approach to how we protect our most valuable resource,” she said.

The bill introduced Monday would establish a $50 million grant program in the U.S. Forest Service to be used to match local conservation projects. Federal grant funds would have to be matched with state, local or private money.

Priorities would be given to projects that prevent land from being developed while still allowing logging, as well as to those areas that are most severely affected by urban sprawl.

Collins said she got involved after reading a newspaper article last summer that said development in metropolitan Portland is consuming more acres per person than in any other city in the Northeast.

She said she looked for available federal programs to help with the problem and found there are none.

The Forest Legacy Program, administered by the U.S. Department of Agriculture, only can be used for preserving large tracts found in northern Maine, said Tom Doak, director of the Maine Forest Service.

Everett Towle, director of the Small Woodlot Owners Association of Maine, said woodlots provide jobs and also recreational opportunities.

Collins’ proposal will help “keep the kind of culture we enjoy in Maine,” he said. “This is part of the solution.”

Doak said the forest products industry is significant in southern Maine. There are 15 full-time sawmills in York and Cumberland counties, he said, and the two counties together produce 25 percent of the state’s white pine harvest.

Collins’ proposal is supported by a broad coalition that includes environmental groups and the forest products industry.

“It’s a powerful coalition,” said William Vail, a local representative for Collins and a former commissioner of the Maine Department of Inland Fisheries and Wildlife. “Many times these two groups are seen as being at odds with each other.”