At 7 a.m. almost every weekday morning this winter when the six-man Prince George's County forestry crew leaves its maintenance headquarters, its trucks are followed.

And while they are being tailed by cars and pickup trucks throughout the day, the phones are ringing almost non-stop back at the Maryland National Capital Park and Planning Commission office the crew just left. "Where are they?" the callers demand. "What's the address?". . . I was just there I didn't see anything at all. Are you giving methe runaround?"

The reason for the close, often angry surveillance, is firewood, free firewood.

The pursuit and harrassment of the forest crew, which trims dead and dangerous trees in the county's 13,000 acres of woodlands, has escalated this winter so that often it has been difficult to see the forest for the throngs of tree lovers.

"They stand at the men's elbows as they use power saws, waiting for a piece of wood to fall," says Garry L. Perrygo, chief horticulturist for the regional park authority.

But the era of free firewood is at an end. Beginning this spring the forestry crew will gather and sell all the good wood they cut, says Perrygo, which should curtail the crew chasers and which should also net the park agency a profit of about $7,000 a year.

Selling the more than 240 cords of firewood it now cuts and gives away to the first grabber is one of nine park money-making ideas Perygo recently proposed to the Prince George's County planning board, which directs local park affairs for the bi-county park authority.

"They shot down the other ideas," says Perrygo, "largely out of concern they might compete with private business." They included starting both pick-your-own orchards and small fruit farms (blueberries, raspberries, blackberries etc.), a cut-your-own Christmas tree farm, growing and selling corn, hay and nursery stock - all on park land.

There are no pick-your-own-orchards or fruit farms and no cut-your-own Christmas tree farms in the county, Perrygo reported to the planning board, but there apparently is concern about putting the park agency into the farming business even on a small scale. The farming operations, which Perrygo estimated could bring the parks more that $200,000 a year, would be conducted primarily to provide recreation for county residents as well as a small source of income.

Selling firewood the county already cuts and continuing some minor haygrowing - used to feed the 18 horses of the Park Police cavalry - are the only two of Perrygo's proposals the planning board endorsed. The others were all tabled for further study.

Selling firewood was seen as a way of ending the badgering of the forestry crew, which got out of hand this winter, Perrygo says, because of the cold weather and the great demand for free or cheap firewood. It was also a way to contribute slightly to the park agency's budget, which is being severely cut back this year along with many county programs.

The forestry crew has been cutting dead and dangerous trees, into fireplace lengths, ever since it was formed 10 years ago, says Perrygo. "In theory this is not a bad practice; however, due to the increasing costs of fuel and firewood, both the work crew and the office help are badgered by the public in increasing numbers. People have turned about face from being polite to being overbearing, demanding and rude," he said in his report to the planning board.

"The work crew is followed out of the yard (at 5200 Calvert Rd., College Park) by individuals who interfere with the crew's work and board every piece they can get their hands on - most obviously for its sales potential," Perrygo reported.

More than 75 per cent of the wood that is left theoretically for residents is picked up now by commercial woodsellers who follow the forestry crew around in pick-up trucks, Perrygo said, "and these big guys elbow little old ladies out of the way for the wood, as though they have a right to most of it because they're bigger."

The forestry crew expects ot begin stockpiling all the hardwood they cut up, the prime firewood, but will leave the pine and other softwoods for residents and others cut and stacked beside the road. Commercial woodsellers will still have access to park wood if they care to buy it from the park agency. Perrygo estimated the wood could be sold for $40 a cord on a volume wholesale basis, or slightly more for trunk-load quantities. A cord (a stack of two-feet logs, 4 feet high and 16 feet long) of good firewood, all hardwood, has been selling from $55 to more than $90 this winter, depending on the dealer, location and whether it's stacked.