Gov. Rendell today signed an executive order banning further leasing of state forests for Marcellus Shale natural gas drilling, a move lauded by environmentalists, but shrugged off by Republicans as the symbolic effort of a lame duck leader.

Rendell, who will leave office in January, signed the moratorium in a bitter denouement to the failure to enact a natural gas severance tax, which left Democrats and Republicans blaming each other for the breakdown.

The governor underscored the overt political nature of Tuesday's signing ceremony at Penn Treaty Park in Philadelphia by using the occasion as a call to action in next Tuesday's legislative and gubernatorial election.

"If you care about the environment and care about our local communities, you have to vote Democratic," he said.

Republican leaders said Rendell was playing politics.

"Maybe he thinks it will somehow help the Democratic candidates he's helping to elect," said Senate Majority Leader Dominic Pileggi (R., Delaware). "I don't think it advances on the serious and important issue of how to maximize the benefit of the natural resource we have here in the Commonwealth."

The executive order would put Rendell's successor on the spot to sign a rescinding order if he decided to lease the mineral rights to any more state forest land.

Senate Republican leaders, committed to not raising taxes, are unwilling to declare the state forests off limits to more leasing. About 725,000 of the state's 2.1 million acres of forests have been leased - 65,000 acres this year.

John Quigley, secretary of the Department of Conservation and Natural Resources, said the state can ill afford to lease more of the 1.5 million Marcellus acres without jeopardizing the state's green certification, which supports the state's sustainable timber industry.

Of about 800,000 acres of unpleased Marcellus state acreage, DCNR says that 180,000 are designated as wild and natural areas, 200,000 acres are old-growth forests, 128,000 acres have steep or sensitive terrain, 299,000 acres are virtual wilderness, 88,000 are recreational lands in the Poconos and 20,000 acres in Western Pennsylvania's Laurel Highlands.

"We cannot keep the ecological balance, we cannot keep the character of our wild and natural lands, if we allow any expansion of drilling," Rendell said.

The moratorium is coupled with two other actions the Rendell Administration is taking to protect state forests before the governor exits in January.

On Monday DCNR approved a new policy requiring the state to conduct environmental reviews on drilling on the 290,000 acres of lands upon which the state does not own the mineral rights. Those leases include about 80 percent of the Marcellus lands in state parks, Quigley said.

"It would significantly strengthen the protection of those public lands where we don't own the mineral rights," said Quigley. The state has much more control over drilling on land where it controls the mineral rights, and the terms of the drilling leases.

The department will also announce plans Wednesday to hire 15 experts to begin gathering data and monitoring the environmental impact of shale-drilling on state forests. Quigley called it "the most aggressive monitoring program of any public land agency in the country."

The program's $2 million annual cost will be paid out of gas royalties from the state's Oil and Gas Fund.

Underlying Rendell's action is an ongoing debate about the role the Marcellus Shale boom should play in the state's budget.

Natural gas interests regard unpleased state lands as a potential revenue-generation vehicle for the state's beleaguered budget, while conservationists prefer a statewide production tax as the means for the state to capture a share of the action.