NORTH WATERBORO, Maine — Maine’s distinctive tradition of allowing recreational access to privately owned woodlands and waterfronts may be in jeopardy, in part because of abuses that test the limits of landowner hospitality.

Dale Tarbox had been thinking twice about whether to continue to let the public use a dirt road and trail across his land for launching kayaks, canoes and small motorboats into the clear water of Isinglass Pond.

“It doesn’t bother me, as long as they respect it,” he said.

But that’s not always the case. Standing on the road, Tarbox pointed out a pile of discarded roofing shingles, a half-dozen empty beer cans and the carcass of a dead skunk. Posted on a tree above the shingles is a yellow “No Dumping” sign, with a clear warning that abuse could result in loss of access.

“We put those up [in May] after they brought the hot tub in,” he said.

Maine’s cultural tradition of permissive use is at the core of the state’s character and quality of place, said Richard Barringer, chairman of the Governor’s Council on Maine’s Quality of Place. “To our knowledge, it’s unique, not only in this part of the world, but in the world. There is nothing like it.”

But the tradition is coming under pressure as lands are subdivided, populations spread out and abuses prompt landowners to post their properties.

An estimated 18,000 family forest owners posted restrictions on the use of their land in 2006, three times as many as in 2003, according to a report prepared earlier this year for the Quality of Place Council. An estimated 36 percent of small wood-lot owners had posted their land as of 2005, up from 15 percent in 1991, it said.

“There is absolutely no question that what makes recreational opportunities accessible in the state of Maine are the private landowners,” said Dan Scott, a captain in the Maine Warden Service who works with property owners. “There definitely is an increase in interest about how to post lands or keep people from recreating on their property.”

Everyone from hunters to birdwatchers and snowmobilers to kayakers can be affected by reductions in access, which also can harm rural economies that rely on opportunities for outdoor recreation.

Unlike other rural states with vast swaths of federal lands, Maine is 94 percent privately owned. Under its unwritten social contract, recreational access is allowed on any open lands that are not specifically posted as off-limits. Landowners, meanwhile, have strong legal protection from any liability should a visitor get injured on their unposted property.

Tarbox, a Maine native, said he never really questioned the tradition.

“That’s the way I grew up,” he said. So he understands that none of the people who use his land to visit the pond ever thank him. “They’ve used it so many years, they think it’s there for them,” he said.

He said he’s sure those are not the same people who dumped the shingles, or the old hot tub and other trash that has shown up this year.

Tarbox said he would hate to shut off the road. But, he added, “I just can’t keep lugging stuff off all the time.”

Recognizing the risk posed by loss of access, Gov. John Baldacci’s administration last fall hired Maine’s first full-time director of landowner relations.

Robert Duplessie, a former lawmaker from Westbrook, tries to resolve conflicts before angry landowners cut off access. He often helps post signs that say “No Dumping,” “Foot Traffic Only” or “Access by Permission Only,” a preferred alternative to the “No Trespassing” signs available in hardware stores.

“There’s been some tension in some areas,” Duplessie said, but “I think there’s been some improvement.”

Duplessie arranged for a local all-terrain vehicle club to haul away the hot tub from Tarbox’s land. “I want to keep this access point open to the pond so people can use it,” Duplessie said.

Luckily for the state, he said, Tarbox does, too.