Forest Resources of the United States, 2002

Annual mortality-The average annual volume of sound wood in growing-stock trees that died from natural causes during the period between inventories.Annual removals-The net volume of growingstock trees removed from the inventory during a specified year by harvesting, cultural operations such as timber stand improvement, or land clearing. Bureau of Land Management (BLM)-Anownership class of Federal lands administered by the Bureau of Land Management, U.S. Department of the Interior.Coarse materials-Wood residues suitable for chipping, such as slabs, edgings, and trimmings.Commercial species-Tree species suitable for industrial wood products.County and municipal-An ownership class of public lands owned by counties or local public agencies, or lands leased by these governmental units for more than 50 years.Cull tree-A live tree, 5.0 inches in diameter at breast height (d.b.h.) or larger, that is unmerchantable for saw logs now or prospectively because of rot, roughness, or species.(See definitions for rotten and rough trees.)Diameter class-A classification of trees based on diameter outside bark measured at breast height (4-1/2 feet above ground).D.b.h. is the common abbreviation for diameter at breast height.With 2-inch diameter classes, the 6-inch class, for example, includes trees 5.0 through 6.9 inches d.b.h.Federal-An ownership class of public lands owned by the U.S. Government.Fiber products-Products derived from wood and bark residues, such as pulp, composition board products, and wood chips for export.Fine materials-Wood residues not suitable for chipping, such as planer shavings and sawdust.Forest industry-An ownership class of private lands owned by companies or individuals operating wood-using plants.Forest land-Land at least 10 percent stocked by forest trees of any size, including land that formerly had such tree cover and that will be naturally or artificially regenerated.Forest land includes transition zones, such as areas between heavily forested and nonforested lands that are at least 10 percent stocked with forest trees and forest areas adjacent to urban and built-up lands.Also included are pinyon-juniper and chaparral areas in the West and afforested areas.The minimum area for classification of forest land is 1 acre.Roadside, streamside, and shelterbelt strips of trees must have a crown width of at least 120 feet to qualify as forest land.Unimproved roads and trails, streams, and clearings in forest areas are classified as forest if less than 120 feet wide.Forest type-A classification of forest land based on the species presently forming a plurality of the live-tree stocking.Forest type group-A combination of forest types that share closely associated species or site requirements and are generally combined for brevity of reporting. Major eastern forest type groups:White-red-jack pine-Forests in which eastern white pine, red pine, or jack pine, singly or in combination, comprise a plurality of the stocking.Common associates include hemlock, aspen, birch, and maple.Spruce-fir-Forests in which spruce or true firs, singly or in combination, comprise a plurality of the stocking.Common associates include white cedar, tamarack, maple, birch, and hemlock.Longleaf-slash pine-Forests in which longleaf or slash pine, singly or in combination, comprise a plurality of the stocking.Common associates include other southern pines, oak, and gum.Loblolly-shortleaf pine-Forests in which loblolly pine, shortleaf pine, or southern yellow pines, except longleaf or slash pine, singly or in combination, comprise a plurality of the stocking.Common associates include oak, hickory, and gum.Oak-pine-Forests in which hardwoods (usually upland oaks) comprise a plurality of the stocking, but in which pine or eastern redcedar comprises 25-50 percent of the stocking.Common associates include gum, hickory, and yellow-poplar.Oak-hickory-Forests in which upland oaks or hickory, singly or in combination, comprise a plurality of the stocking except where pines comprise 25-50 percent, in which case the stand is classified as oak-pine.Common associates include yellow-poplar, elm, maple, and black walnut.Oak-gum-cypress-Bottomland forests in which tupelo, blackgum, sweetgum, oaks, or southern cypress, singly or in combination, comprise a plurality of the stocking except where pines comprise 25-50 percent, in which case the stand is classified as oak-pine.Common associates include cottonwood, willow, ash, elm, hackberry, and maple.Elm-ash-cottonwood-Forests in which elm, ash, or cottonwood, singly or in combination, comprise a plurality of the stocking.Common associates include willow, sycamore, beech, and maple.Maple-beech-birch-Forests in which maple, beech, or yellow birch, singly or in combination, comprise a plurality of the stocking.Common associates include hemlock, elm, basswood, and white pine.Aspen-birch-Forests in which aspen, balsam poplar, paper birch, or gray birch, singly or in combination, comprise a plurality of the stocking.Common associates include maple and balsam fir.Major western forest type groups: Douglas-fir-Forests in which Douglas-fir comprises a plurality of the stocking.Common associates include western hemlock, western redcedar, the true firs, redwood, ponderosa pine, and larch.Hemlock-Sitka spruce-Forests in which western hemlock and/or Sitka spruce comprise