The following definitions apply to this subchapter:

(1) "Associated forest land management use" means the primary use of a structure is to support the health, maintenance, growth, or harvest of the forest on the subject property.

(2) "Capable of producing timber that can be harvested in commercial quantity" means:

(a) forest land that can produce 100 board feet or more of lumber per acre per year in live softwood trees as measured using the Scribner Log Rule, at the culmination of the mean annual increment for fully stocked, natural stands; and

(b) is at least 10 percent stocked with softwood timber of any size on an area at least 120 feet in width; or

(c) has been converted from another use and exhibits a minimum stocking rate of 300 seedlings and/or saplings per acre (12-foot average spacing); or

(d) does not meet the stocking requirement specified in (b) or (c), but has had the trees removed by man through timber harvest or by fires and other natural disasters, and has been, or will be, naturally or artificially regenerated within ten years.

(3) "Board foot" means a block of wood equivalent to one inch thick by 12 inches long by 12 inches wide.

(4) "Contiguous parcels of land" means separately described parcels of land under one ownership that physically touch one another or would have touched one another were the acreages not separated by:

(a) deeded roads and highways;

(b) rivers and streams;

(c) railroad lines; or

(d) federal or state land that is leased from the federal or state government by the taxpayer whose land is physically touching the federal or state land.

(5) "Cubic foot" means a block of wood equivalent to 12 inches thick by 12 inches long by 12 inches wide. There are approximately three to five board feet of finished lumber in one cubic foot of wood. The midpoint of this board foot to cubic foot conversion range is approximately four. The precise ratio varies with tree diameter, form, taper, and defect. In the productivity model developed by the University of Montana – College of Forestry and Conservation, the conversion factor is one cubic foot will equal four board feet.

(6) "Culmination of mean annual increment" means the point of maximum mean annual volumetric yield production in a tree or stand of trees. This point is also referred to as the biological rotation age.

(7) "Diameter at breast height (dbh)" means the average stem diameter, outside bark, at a point 4.5 feet above the ground.

(8) "Forest site productivity class" means the range of timber production potential of a site expressed in terms of board foot volume growth per acre per year at the culmination of mean annual increment in fully stocked natural stands.

(9) "Fully stocked" means the highest degree in which a stand could fully utilize the site's capacity to grow trees.

(10) "Hardwood Species" means a taxonomic group of species commonly referred to as broadleaf trees. Examples of hardwood species that are native to Montana are alder, Rocky Mountain maple, birch, aspen, and cottonwood. Native hardwood species are generally considered to be noneconomical to process into lumber products in Montana and are not classified as commercial timber species for the purpose of this rule.

(11) "Land use" means the type of service or utilization of the land.

(12) "Mean annual increment (MAI)" is a measure of the average yearly increase in growth produced in a tree or a stand of trees. This increment can be calculated by dividing total tree or stand growth by the total age. Mean annual growth changes during different growth phases of a tree or stand of trees. MAI typically increases during the tree or stand's juvenile developmental stage, attains a maximum growth increment at a point in the stand's middle development, then decreases as the tree or stand becomes more mature.

(13) "Natural stands" means fully stocked, even-aged softwood stands which are naturally regenerated.

(14) "Noncontiguous parcels of land" means parcels of land under one ownership that are physically separated from one another by land in a different ownership other than:

(a) deeded roads and highways;

(b) rivers and streams;

(c) railroad lines; or

(d) federal or state land that is leased from the federal or state government by the taxpayer whose land is physically touching the federal or state land.

(15) "Nonforest land" means land that is at least 120 feet in width and at least five acres in size, which does not meet the requirements of ARM 42.20.705. Nonforest land can include rivers and streams, roads, highways, power lines, railroads, and noncommercial tree species.

(16) "Ornamental trees" means trees grown commercially to ornament and decorate or for use as shade trees or windbreaks.

(17) "Owner" means that the applicant and owner of record are the same individual, corporation, or partnership.

(18) "Parcel" means a tract or plot of land distinguishable by ownership boundaries.

(19) "Producing timber" means growing trees, including trees removed through harvest, clear-cut, or by natural disaster, such as fire.

(20) "Residence" means all conventionally constructed homes, as well as all mobile homes and manufactured housing, that may serve as living quarters for one or more individuals or a family. The occupancy of the residence shall be irrelevant.

(21) "Scribner Log Rule" means a forest industry recognized mathematical formula that estimates the net board foot lumber volume that can be sawn from a log that is scaled to a specific diameter and log length. Volumetric yields are based on softwood trees at least 8.0 inches in diameter at breast height (outside bark). Tree volume is measured from a one-foot stump to a six-inch inside bark minimum top. Board foot estimates using the Scribner Log Rule are based on 16-foot nominal log lengths with five percent hidden defect.

(22) "Softwood species" means conifer species that can be economically processed into lumber. Some examples of softwood species that are native to Montana are ponderosa pine, Douglas-fir, larch, lodgepole pine, spruce, and alpine fir.

(23) "Site" means at least 15 contiguous acres with the capacity to grow timber.

(24) "Stocked" means a measure of the degree to which an area is effectively covered with living trees.

(25) "Timber" means softwood species that can be economically processed into lumber. Whitebark pine, limber pine, and Rocky Mountain juniper are generally considered to be noneconomical to process into lumber products in Montana and are not classified as commercial softwood species for the purpose of this rule.

(26) "Under one ownership" means one party owns two or more parcels of land when the title is in the party's name or names; the party has received title in the parcels by a transferring instrument such as a deed, contract for deed, or judgment; and the party has the present right to possess and use the parcels.

(27) "Uninterrupted forest land" means forest land that meets the requirements of ARM 42.20.705 and is unbroken by nonforest land.

(28) "Volume" is expressed in net board feet as measured by the Scribner Log Rule.