Forests of Alaska

THE INTERIOR FOREST

The Central Plateau region of Alaska is within the zone of the white spruce-white birch forest type, which grows throughout the subarctic belt of North America from Newfoundland to Bering Sea.

The vegetative cover of central Alaska has never been mapped, but the zone within which there is timber probably covers as much as 340,000 square miles, or about 220,000,000 acres. The area actually in tree growth is roughly estimated to be 80,000,000 acres. Of this total, 40,000,000 acres consists of fairly dense stands with well formed trees having a maximum diameter of about 30 inches. Another 40,000,000 acres comprises open woodland with scattered limby trees. The total timber volume, estimated conservatively at 5 to 7 cords per acre for the entire area in tree growth, amounts to about 500,000,000 cords.

The Central Plateau Region has other types of vegetation that have close physical and economic relationships with the timber. They consist of the true grasslands, which cover extensive areas, and an even larger patch-like arrangement of brush, tundra, coarse grass, and peat moss intermixed with stands of stunted, pole-size black spruce. All these classes of vegetation help make up the cover of the forest zone of 220,000,000 acres.

The forests of fairly dense stands are the most important commercially for utilization. They are composed of varying percentages of white and black spruce, the latter a very slow-growing species, and white birch with frequent admixtures of cottonwood. In many places the spruce grows in practically pure stands, while in others the white birch is predominant. The forests of this class reach their best development on deep, well-drained soils of benches and valley floors, especially in the watersheds of the Susitna and Matanuska Rivers of the Cook Inlet region, the main Yukon, and the Tanana Rivers. The trees seldom exceed 30 inches in diameter and 50 or 60 feet in height, and are usually limby.

The open woodland consists principally of a thin stand of small white birch, white spruce, balsam poplar, and aspen in varying mixtures. No sharp line of demarcation exists between the open woodland and the dense forests. In general, the timber cover assumes the open woodland form on the poorer soils and more exposed sites.

The timber line is low, generally between 500 and 1,000 feet above the main valley floor. Local conditions unfavorable to tree growth hold the timber line to much lower limits in many places.

The timber of the Central Plateau is unlikely ever to move into general world markets because of its remoteness and small size, but it can contribute substantially to the home-making needs and industrial activities of the local population of this growing pioneer region.

The two principal species, white spruce and white birch, taken together, supply many of the needs of local industry and settlement covering a great range of products from fairly heavy timbers to furniture and fuel. Small sawmills widely scattered throughout interior Alaska cut white spruce lumber for mine flumes, residences, and other local uses.

The open woodlands, brush, grass, and tundra areas support exceptionally large populations of various big game and fur-bearing animals in which the whole of America has a keen interest. These lands can also supply forage for an extensive domestic livestock industry when economic conditions call for their use for this purpose. The vegetative cover in all of its forms helps to conserve the scant rainfall of interior Alaska for use by the important local placer-mining industry. Again, the several kinds of vegetation contribute materially to the exceptional natural beauty of Alaska.

The White occupation of interior Alaska, which began substantially in the gold-rush days of the early nineteen hundreds, brought with it the blight of extensive forest fires. Annual precipitation in the region is less than 15 inches, the summers of almost continuous daylight are dry and warm, and the ground cover of moss and larger plant growth is highly inflammable. Widespread and repeated burns have naturally resulted from the hazardous conditions. Fire should be brought under control at the earliest possible date, both to conserve the natural vegetative resources for present and future economic use, and to preserve the scenic beauty and wildlife of this last extensive wilderness on United States soil. The land involved is almost entirely in Federal ownership and under the administration of the Department of the Interior. The General Land Office of the Interior Department started systematic fire protection here in 1939 with an allotment of $37,500 and a small organization. This effort will doubtless be enlarged in scope in succeeding years. All local residents, as individuals and through their public and quasi-public organizations, should advocate and practice the outdoor code, "BE CAREFUL WITH FIRE—IT PAYS."