FOREST LAND AND TIMBER RESOURCES 



83 



sippi Delta. These types are notable not only 

 for a rich variety of species growing on some of 

 the inherently most productive hardwood sites 

 in America, but also because they contain a large 

 part of the remaining supply of high-quality 

 hardwood. 



The maple-beech-birch type group, representing 

 about 13 percent of hardwood types, is about 

 equally distributed among the New England, 

 Middle Atlantic, and Lake States regions. In 

 these types yellow birch and sugar maple are the 

 preferred species for the long-established lumber 

 and veneer industries. 



The oak-pine type is largely concentrated in 

 the South, where it frequently represents a resid- 

 ual stand left after cutting of merchantable pine 

 in mixed pine-hardwood forests. Much of this 

 type is better adapted to growing pine than 

 commercial hardwoods. Through cultural prac- 

 tices such as cull hardwood removal, extensive 

 areas have been reconverted to productive pine 

 types, and other stands offer similar opportunities. 



The aspen-birch types are pioneer associations 

 that have invaded large areas of cutover land in 

 the North. A considerable portion of this type 

 occurs on productive land that formerly supported 

 pine. Here there is an opportunity to increase 

 the acreage of pine type through planting or 

 other stand conversion measures. Some portions 

 of these types are reverting to maple, beech, or 

 birch, or to spruce and fir. In other areas where 

 aspen is important to the pulp industry, attempts 

 are being made to maintain the existing cover. 



Douglas-Fir and Ponderosa Pine 

 Most Extensive Types in West 



Nearly 30 percent of the commercial forest land 

 in the West carries stands in which Douglas-fir 

 predominates (table 55). Most of this type is on 

 the Pacific coast, mainly in the outstandingly 

 productive area west of the Cascades, but Douglas- 

 fir stands also are widespread in the Rocky 

 Mountain States. 



The ponderosa pine type almost matches the 

 Douglas-fir type in area and importance. Pon- 

 derosa pine occupies a large acreage in eastern 

 Oregon and Washington and is the most extensive 

 commercial forest type in California and the 

 Rocky Mountains. 



Together, the Douglas-fir and ponderosa pine 

 types are the Nation's principal current sources 

 of softwood timber for the production of lumber 

 and plywood. None of the other western types 

 approaches either of them in acreage, although in 

 the aggregate these other types make up 46 

 percent of the commercial forests in the West. 



Several of these other types are important sources 

 of timber products, particularly those containing 

 species noted for high quality and specialty uses, 

 such as western white pine, sugar pine, and 

 redwood. 



The hemlock-Sitka spruce type, particularly 

 important for pulp wood, occupies nearly all of 

 the commercial forest land in coastal Alaska and 

 is the characteristic type along the coast in Oregon 

 and Washington. Lodgepole pine and spruce-fir 

 types are widely distributed at high elevations 

 in the West and are receiving increasing attention 

 for industrial development. The larch type in 

 the Northern Rocky Mountain Region is an 

 important source of both saw logs and poles. 

 Hardwood types, located principally in western 

 Oregon and Washington, occupy 8 percent of the 

 commercial forest land in the West. 



STOCKING OF FOREST LANDS 



In past forest surveys stocking classifica- 

 tions have been used as a measure of occupancy 

 of land by "growing-stock trees," i.e., all live trees 

 except cull trees. Such classifications, however, 

 ordinarily do not provide an adequate measure of 

 the "condition" of the forest or its potential for 

 management. In current forest surveys stocking 

 data are therefore being compiled to show occu- 

 pancy of land by major classes of growing stock 

 and other cover, including (a) desirable trees, i.e., 

 the kind of well-formed, sound, vigorous trees that 

 forest managers aim to grow, (b) acceptable trees, 

 which include other trees meeting the minimum 

 requirements for growing stock but too poor in 

 quality and /or vigor to qualify as desirable trees, 

 (c) sound culls or rough trees, (d) rotten chills, and 

 (e) inhibiting shrubs or other cover. Stocking by 

 these classes is determined from tallies of trees on 

 clusters of 10 variable plots distributed over 

 approximately 1 acre. 



Desirable Trees Occupy 

 Limited Portion of Forest Area 



Stocking by tree classes is as yet available for 

 only a limited portion of the United States, but 

 recent figures for Georgia provide an illustration 

 of the proportions of commercial forest lands 

 occupied by different classes of cover as follows: 



Percent 



Desirable trees ^^ 



Acceptable trees ^° 



Total growing stock 68 



Cull trees I] 



Nonstocked with trees jj_ 



Total 100 



