There sits the Christmas tree-brought to your living room by an increasingly large-scale agribusiness system that nurtures the tree from the mass produced seedlings to the final plastic-webbing-wrapped product.

More and more tree farmers, many of them part of family ventures of part-timers, are growing more and more trees to decorate for Christmas.

More than 30 million trees are expected to be sold nationally thi year. By the time they roll into retail markets, after being baled on Christmas tree plantations, loaded onto industrial shipping pallets and trucked down the nation's highways, they will be worth about $300 million.

Maryland Christmas tree growers will account for about 95,000 of those trees, judging from last year's figures. Nearly 100 growers-ranging from accountants and doctors who raise a frew trees on choose-and-cut type farms to full-time growers with 200-acre plantations in Western Maryland -- have joined the ranks of Christmas greens grocers.

"Economically it's really been contributing to the agricultural economy in this state," said George Roche, a marketing specialist with the Maryland State Department of Agriculture. "We've got about a hundred people growing trees and we started with only 30 or 40 ten years ago," he said.

Maryland Christmas trees growers and their counterparts across the nation have a hard row to hoe as tree farmers. Not only do they contend with cold and drought, diseases and pestilence in such forms as the pinet-tip moth (which chews on the ends of pine needles), they must also wait six to eight years to harvest their crop. Then the trees head to market for a make-or-break three-week sales season. "We get our bread and butter in . . . three weeks," said Cindy Stacy. Stacy and her husband Marshall Stacy are full-time growerswith 60,000 trees on 200 acres in Garrett County. This year they cut 5,000 trees.

"For every tree you cut, you plant three," said Cindy Stacy. "Last spring we put in over 35,000 trees. That's how many little baby went into the ground," she said.

The Stacys use a tree planter, one of the tools of a trade that has developed its own sort of service indusrty. There are mechanical transplanters that automatically take seedlings, put them in the ground and close the hole around the seedling planting as many as 10,000 trees a day. There are tree balers, shearing knivesand paint sprayers, used on trees such as the scotch pine with needles that turn yellow in the fall.

In some states migrant workers help shearthe trees in the summer -- a process something like pinching back houseplants to make them branch out. The same migrants may come back in late fall to help harvest, according to Mary Garity of The National Christmas Tree Association. On one large operation in Salem, Ore., the grower uses a helicopter to move cut trees to a loading area, she said.

In states such as Maryland where the growers run relatively smaller operations, they frequently hire teenagers. "We have a crew going all summer longshearing trees from the local boys forestry camp," said Stacy. During peak periods such as spring planting, summer shearing and the November harvest, the Stacys employ about 15 people to work with them. During therest of the year, they employ only a foreman.

Once the trees are cut, the problem can be how to get them to market."Three of four years ago we had to get a bulldozer in here to get the bulk of our trees out and onto the truck," said Stacy. Snow at the front gate was piled as high asher husband's neck, she said. "There were a few we never did get out. We came back at the spring thaw and saw that we didn't get out," she said.

The Stacys bought the tree farm in 1970, as part-time growers living in Columbia, where Marshall Stacy was in the landscaping business and his wife worked on public relations for the new town of Columbia. "For the last three years, we've been totally Christman trees," said Cindy Stacy. "We've been living here full-time for two years." The Stacys, whohave two small children, ski and snowmobile between the hectic Christmas sales season and spring planting.

Another Maryland grower, John Theofield of Silver Spring, who is president of the Maryland Christman Tree Association, is a self-employed accountant who also runs a 100-acre tree plantation in Frederick County.

"I got into the business by fluke," said Theolield. He and some colleagues, who shared his desire to spend time outdoors, bought land as a hedge against inflation and began rasing trees. With demand for real trees growing, "We're trying to stuff a tree into every corner we can," said Theofield of himself and other growers.

"Being a very conservative businessman, as I am I would not be in the business unless I made a dollar," he said.