Deer have caused the thinning of undergrowth in woodlands of the Jug Bay Wetlands Sanctuary. And while it may look beautiful to hikers whose views into the forest are unimpeded for hundreds of yards, experts see an impending disaster unless the white-tail deer population dramatically drops.

"We could be seeing it (irreparable damage) now," said Christopher Swarth, superintendent of the 1,500-acre sanctuary. "There's concern that the forests as we know them may not be around in 50 or 100 years."

Without any natural predators, the deer herds have bloomed to a concentration three times higher than Mr. Swarth and deer experts believe the sanctuary could support. Hunting may be the only way to reverse the damage.

Deer overpopulation has become a problem statewide.

The deer concentration at Jug Bay - about 45 deer per square mile - is dwarfed by problems in suburban Maryland. Some places in Montgomery County have seen as many as 100 deer per square mile.

"Although we feel like we have a high density of deer, we don't have a monstrous population," Mr. Swarth said.

At Jug Bay, the animals chew through tasty forest vegetation less than 6 feet from the ground, gobbling up saplings that help the forest regenerate, and killing habitats for a slew of nesting birds, turtles and other ground creatures. The deer overgraze, leaving behind plants theylike, knocking the sanctuary's ecosystem out of balance, and in some cases, nearly eradicating some species.

The Pink Lady Slipper orchids that were common a decade ago have been overgrazed by deer so much that they are now a rare find, Mr. Swarth said.

While he and county Parks Administrator Mark Garrity emphasize that hunting would be only a piece of the wildlife plan to manage the deer population, an expert from the Maryland Department of Natural Resources says it works best.

"There's a lot of different methods out there, but by far, the most efficient and effective is hunting," said Bob Beyer, associate director of DNR's Wildlife & Heritage Service.

Although community associations and state agencies use hunting elsewhere in the county to control nuisance deer populations, it is effectively forbidden on county-owned land.

County Executive John R. Leopold this week introduced a bill to allow firearms and hunting in county parks only when the killing is part of an approved wildlife management plan.

The bill solves two problems for county officials: It allows parks managers to control the deer population at Jug Bay, and it dissolves a hurdle that has prevented the county from taking ownership of another nature preserve in Crownsville.

Last year the state agreed to donate 546 acres of woodlands west of Interstate I-97, but it now refuses to transfer the deed unless the county continues the bow-hunting program that currently controls deer populations on the land, county officials said. That program could not continue unless county laws about hunting are changed.

Maryland "had hardly any deer" in the 1950s, but the urbanization and lack of predators have caused the statewide deer population to grow to 230,000, Mr. Beyer said.

Overpopulation has become such a widespread problem that the state devoted two full-time biologists to managing deer populations, Mr. Beyer said.

In Anne Arundel, community associations and private land owners who are fed up with deer munching yards or darting in front of cars, have brought in nonprofit hunting organizations to thin the deer populations.

J. Dale Emerson, president of the Tri-County Deer Management Association, said his group has several deals with land owners in the Annapolis area to hunt deer with bows and arrows.

At Jug Bay, deer have wandered off the sanctuary and eaten as much as 30 percent of the soybean crops of a neighboring farmer.

"They love the beans," Mr. Swath said. "It drives the farmers nuts."

The larger problem, said Mr. Garrity from the county parks department, is the imbalance the deer population creates in the ecosystem.

"You've got your big trees, and then you got your medium trees, and then you got your shrubs and then you got your seedlings. And that's your life cycle," Mr. Garrity said. "The deer are sort of taking care of the seedlings and shrubs, and those are the future when the big trees blow over or die someday. If you don't have something 25 years old when the 100-year-old tree falls, you have a huge gap for years."