Environmentalists are facing their annual Christmas quandary: reusable plastic or recyclable wood?

"The artificial Christmas tree represents a bit of a dilemma for green consumers," said Joel Makower, publisher of the monthly Green Consumer Letter. "It seems phony and far from ecological, but it is a reusable thing and eliminates cutting a tree and sending it to a landfill."Some people, of course, have no doubts about which tree to choose.

"A real tree equals a real Christmas," said Jeanne Weiss, spokeswoman for the National Christmas Tree Association in Milwaukee, Wis.

"Real trees are recyclable, they're a renewable resource and biodegradable, whereas fake trees are generally made out of petroleum byproducts and metal," she said.

Christmas trees are farmed on about a million of acres of land in all 50 states, taking seven to 15 years to grow to suitable height, the association said. Seedlings are planted to replace each year's harvest of about 36 million trees, very few of which come from wild forests any more.

"Personally, I wish people would buy more plastic trees because that's what I sell," says Meyer Stopol, vice president of New York's James A. Cole Inc., a major importer of artificial Christmas trees, nearly all of which come from the Far East.

"People today decorate much earlier at home. By the time Christmas comes, the (real) tree's dried out," he said, adding that the trees are put out as garbage after the holiday.

Artificial trees, Stopol says, can last for many years.

The truly committed may opt for a living, potted Christmas tree, plantable outdoors after the tinsel comes down.

But that can be a lot of trouble, especially in parts of country where the ground may freeze by late December.

"Something like that takes planning," Weiss said. "In some areas, it's not a viable option."

Makower suggested that a living indoor holiday tree need not resemble a towering forest pine.

"There's no question that having a live Christmas tree is the greenest thing to do," he said. "A small potted plant will do."

But not everyone will be ready to settle for trimming the schefflera or hanging spider plant.

Environmentalists say the most important thing is making sure the tree doesn't just go into the trash after the holidays.

Pine needles are good conditioners for some soils. The trunks can be cut up for garden stakes or shredded for mulch. And more and more nurseries and county parks departments are eager to accept dead Christmas trees to get the mulch.

The Ikea home furnishing chain, which has six stores mostly on the East Coast, is even willing to lease a Christmas tree for $20.

Mark Wells, operation manager for Ikea's outlet in Dale City, Va., said customers who bring back their tree on the first or second Saturday in January will get either a $10 refund plus their own mulch, or $20 toward a $100 purchase if they leave the mulch for Ikea to donate to the local parks department.

"We lose money on the deal," he said. "But we're proud that we try to do something to help the environment."

Makower said no one should think one tree a year is too small a matter to make a difference.

"If we've learned anything in the environmental movement, it's that we should celebrate the Earth in everything we do, whether it's in celebrating Christmas, Hanukkah or even the winter solstice," he said.