Near Osierfield, Ga. — One of the best ways to understand the Southern timber industry may be to think of the South as a giant hothouse. That's easy to imagine on a late summer day when the heat and humidity leave one feeling like a toasted marshmallow about to go squish between two graham crackers.
But that same moisture and heat which give Georgia a long growing season for its row crops also give it a nice long season for another product you might not even think of as a crop: trees.
Yet Georgia's tree farmers certainly think of trees as a crop. ''Planting trees is a lot less of a gamble than row cropping,'' observes Milton N. (''Buddy'') Hopkins Jr., who does both. Trees suffer less from drought, and if lumber prices are low, tree farmers can hold off selling their crops.
Mr. Hopkins has between 2,000 and 3,000 acres of timber - he isn't quite sure offhand. ''Some of it I bought, some I inherited, I swapped some.'' He lives in what was Osierfield's train depot until the cotton economy ''fell kerplunk,'' to borrow his phrase, during the depression. His father-in-law bought it for $500 around 1950, and Mr. Hopkins moved it to his farm during the middle 1970s. Now the various waiting rooms have become his front parlor, his second parlor; the kitchen communicates with the dining area by means of the erstwhile ticket window.
The warehouse that once stored bales of cotton destined for Atlanta has become his living room. The front yard is decorated with a cactus garden and a collection of peafowl that wander around like ambulatory art objects. ''I like to hear 'em hollerin' out there,'' he comments cheerfully after one lets loose a startling blast.
As the tree farmer has taken over the station built to ship cotton, so pine trees have supplanted cotton. When he inherited his farm from his father-in-law in 1955, he planted pines in one of the old cotton fields. ''They're cutting some of those trees now and it feels real good.''
Indeed, across the state, timber cutting and lumber production have risen in response to the housing recovery. The statistics aren't there to show it yet. But Leon Brown, associate director of the Georgia Forestry Association, reports that ''all 96 of our board members, smaller operators and all, are feeling upbeat. Smaller timber companies, who were just hanging in there before, are rolling again. Orders are double or triple what they were last year.''
Mr. Hopkins indicates some ''super improved trees'' just outside the house. They tower 30 feet high. ''Those trees are four years old.''
The forest products industry, encompassing building materials and pulp, has shifted its center of gravity to the Southeast over recent years. Technological developments have made it possible to make plywood - once almost exclusively a West Coast product - from fast-growing Southern pines.
The growth of the Southeastern market, particularly in housing, has helped the Southern timber industry. Forest products are reckoned to contribute $9 billion annually to Georgia's economy and to employ 74,000.
James M. Montgomery, executive vice-president of the Southern Forest Institute in Atlanta, notes that Southern timberlands tend to be in private hands, rather than under government control. Timber companies like that. Several important companies have a major presence in Georgia, mostly in metro Atlanta: Kimberly-Clark Corporation, of Neenah, Wis.; Mead Corporation, of Dayton, Ohio; and Champion International of Stamford, Conn. The growth of the Southeastern housing market has also helped timber firms.
One of the clearest recent signs of this shift in the ''center of gravity'' has been Georgia-Pacific Corporation's move of its headquarters back to Georgia, to Atlanta, last summer - a move remarkable for being undertaken at the low point in a timber industry recession. The company started in 1927 as a hardwood lumber sales concern in Augusta, but in the mid-1950s followed plywood technology out to the Pacific Northwest. When Georgia-Pacific started making plywood from Southern pine, the Southeast reemerged as the most important region for its operations.
''Georgia is of course a very important state in the Southeastern states, and the Southeastern states really have the potential for being a major part of the world's 'fiber basket,' '' says T. Marshall Hahn Jr., Georgia-Pacific's president and chief executive officer.
''In the Southeast, the climatic conditions enable us to grow high-quality fiber really advantageously compared to nearly any other part of the world, and certainly compared to all of the developed countries. This provides the basis for a tremendous forest products industry, which can contribute significantly to our balance of trade.''
The Southeast's strength in the timber industry is ''a combination of fiber growth and the infrastructure to support the mills that can convert the products ,'' he adds.
On the economic outlook, Mr. Hahn says, ''We have been seeing the recovery, and we're still confident of 1.5 to 1.6 million housing starts this year.'' Recently rebounding interest rates are beginning to pinch, he says, but ''we're hopeful we'll see these rates peaking and falling, and we're still projecting 1. 6 to 1.7 million housing starts in 1984.
''Pulp and paper tends to follow the building products recovery by 6 to 12 months; we're certainly past the trough in that business line, but we are concerned about the strong dollar, which is a problem in the exports area.''
The Southern Forest Institute's Mr. Montgomery, looking a little further down the road, is concerned about the patterns of timberland ownership. On one hand, the Southern forest - 25 million acres in Georgia alone, 68 percent of the state - is ''very democratic,'' he notes; that is, 73 percent of commercial forest land belongs to private individuals, and not industry or government.
''The sense of the value of 'being landed' is very strong in the South,'' he says. Roughly one family in 6 or 7 owns timberland, though in many cases just a few acres.
But the average woodland owners are in their 60s, he observes - of an age either to have inherited land from their parents or to have made the sort of investments generally not possible until the house is paid for and the kids are through college.
Given the length of time it takes a ''crop'' of trees to mature, landowners need to ensure that their heirs will be able to manage their forests to meet the continuing demand for timber - a need, Montgomery maintains, which is not generally appreciated as subdivisions gobble up the countryside. ''People can see wheat fields and think bread, but relating trees to the essential 2-by-4s under brick and wallpaper is something else. People don't see trees as homes for kids.''
Robert G. Kerr, executive director of the Georgia Conservancy, echoes Montgomery's concern about development encroaching on woodlands. But he is also concerned that the active forest ''management,'' particularly the concentration on single species of fast-growing pines, could turn at least parts of the Southeast into a ''biological desert,'' with little or no diversity in the type of food or habitat it provides for wildlife. Hardwoods take much longer to become commercially harvestable, but are a necessary part of the ecosystem, conservationists maintain.
What's more, ''monoculture,'' as the practice of cultivating a single species is known, could leave vast areas exposed if some pest or disease attacked that one species.
What could prove to be an insurance policy here, Mr. Kerr says, is that so many of the Southeast's small landowners are not actively ''managing'' their acreage, but are just letting trees grow, hardwoods and all.