The forest of tomorrow may be made up of "trees" that grow no more than 15 feet tall - but which reach that height in a single year. Or it may be composed of giant supertrees which grow twice as tall as normal trees in half the time.

The fiber from those same forests could be used to produce not only lumber for houses and pulp for paper but also fuel for cars and feed for livestock and poultry.

Government and the big timber and paper companies are spending millions of dollars on ways to transform in the laboratories some of nature's oldest forms - trees - and to convert them into new products.

In keeping with their new view of themselves as "resource companies," the multipulps are looking at new ways to maximize the uses, and the orofits, from their vast holdings. Some of the timber and paper giants are predicting a "pulp revolution" similar to the "gree revolution" that has sharply increased per acre production of wheat and rice worldwide through genetic improvement and cross breeding in the last two decades.

Most of the trees that are cut down today have developed in a state of nature, with very little artificial tinkering by man. But officials of Weyerhaeuser, the world's largest timber company, now talk of man-assisted increases in wood yields similar to those that boosted the per acre output of corn in this country from 5 bushels when the first settlers arrived to more than 200 bushels today.

Weyerhaeuser has found ways to stimulate early flowering of trees - the event that marks the start of sexual reproductive ability - so as to shorten the time between successive generations of superior trees.

Weyerhaeuser, International Paper and several other multipulps are performing laboratory studies on plant tissue to see if identical copies of a single superior tree could be grown by the millions from the cells of that tree, thereby shortcutting the lengthy breeding process.

"Supertrees" already are being grown in the United States by the standard grafting technique of implanting cutting from large trees of a species onto the roots of other seedlings.

The aim of the companies is to make the most intensive use of their land resources. Weyerhaesuer predicts that "wood production may be doubled by genetics alone."

Bur accourding to a scheme that has attracted commercial interest, the best way of doing this may be not to grow trees at all, but tall, gangly plants called kenaf, whose bark can easily be ground up and used for newsprint.

Kenaf, a relative of cotton and okra, is a sort of Jack-and-the-beanstakl plant resembling giant wheat shoots. It has been known to grow to the phenomenal height of 25 feet in a single season, although 15 feet is more normal. The outer bark is made up of long fibers that are suited to making newsprint - a purpose it already serves in timber deficit countries such as Australia.

Federal officials say kenaf for newsprint is past the search phase. The Department of Agriculture's Northern Utilization Laboratory in Peroria, III, successfully made paper from it recently. Paper company officials will meet here Monday to discuss commercial usage with federal officials.

"There are 3,000 acres of kenaaf in the county now - but someday there could be hundreds of thousands," said the department's research agronomist, Austin Campbell.

Kenaf reportedly appeals to paper companies that want a larger share of the American newsprint market, now dominted by Canadian newsprint producers.

Kenaf has produced more new fiber per acre annually than trees and can be planted close to paper mills that are running out of nearby timber supplies. It can be harvested with sugar cane harvesters. Its economic drawback is that it would require annual planting and harvesting - a considerable cost in energy and labor - and money would have to be spent protecting it from nematoid soil worms.

An even more promising experiment wnvolves growing trees like crops, using all the techniques already employed in intensive agriculture. Timber companies plant seedling trees now, but except for occasional spraying, they usually leave the rest to nature.

Now, however, federal experimenters in Rhinelander, Wis., claim to have achieved remarkable results by "farming" with poplar hybrids which are abundant in northern Great Lakes states.

The new farming techniques plant trees close together and harvest them like a crop when they start to interfere with the growth of adjacent trees. Wood yields from this kind of culture have proved to be, three to five times greater than in wild timber stands.

The experiment, is financed by the U.S. Department of Energy and the U.S. Forest Service. Poplars spaced one foot apart produced 20 tons to 24 tons of wood per acre after four years, Compared with less than 5 tons for poplars in natural stands. Production decreased somewhat when the poplars were spaced two feet apart.

"paper companies are crying for data on this and setting up their own pilot studies near mills," said wood scientist Judd Isebrands.

As more timberland is allocated to real estate development, parks, wilderness, roads, and ski resorts, pressure on the companies to utilize the, existing timberlands more intensively seems sure to increase.

In the economics of the timber and paper industries, however, what grows on that land is viewed not as trees but as reserves of fibers and chemicals. Tree fiber already produces products ranging from lumber to paper deapers, but some companies now are studying new ways of tapping the "chemical factories" in the forests to produce food and fuel.

Wood sugar and wood molasses already are produced commerciall and high protein cottonwood tree leaves are now being fed to dairy cows in a federal experiment. The leaves are sid to have the nutritive value of alfalfa.

One far-out but feasibale, use of the chemicals in wood is as an automobile fuel.

Methanol - similar to old-fashioned wood alcohol - can be made by heating wood in a gasification process. The resulting carbon monxide and hydrgen vapors make liquid methanol when compressed.

Methanol can be added to gasoline to save petroleum-based gasoline, and automobile enginess could even be converted to burn only methanol. But methanol produced in this way costs about $1 a gallon and is not several scientists.

"The potential is there, but the likelihood of sudden realization in not," said Ralph Frederickson, a Cincinnati chemical engineering consultant.

One obstacle to wider use of wood based methanol is the fact that it apparently can still be produced more cheaply by gasifying coal.