BASAL AREA is measurement of stand density and is expressed in square feet per acre. It is measured by adding up the cross-sectional areas at breast height of all trees on an acre of ground.
BOARD FOOT is a unit of measure used to determine the volume of lumber and other wood products. It is defined as a piece of wood 12 inches long, 12 inches wide and 1 inch thick, or 144 cubic inches of wood.

BOLE is the trunk or main stem of the tree.

BROWSE as a verb: the act of an animal feeding on vegetation; as a noun: browse is vegetation, available to deer and other forage feeders. It may consist of herbs, weeds, grasses, low shrubs, small trees and very low branches of larger trees.
CANOPY is the cover formed over the ground by a contiguous grouping of tree crowns at approximately the same height.
CONSERVATION is the wise use of our natural resources.
COOPERAGE is a term describing wooden containers such as barrels and kegs. There are two types of cooperage:
 (a) Tight cooperate refers to barrels and kegs  designed to hold liquids.
 (b) Slack cooperage refers to barrels and kegs designed for packaging dry commodities (not watertight).
COVER refers to any type of vegetation which aid wildlife in concealment from predators.
LIVE CROWN is that part of the branch area of a tree which is living and has leaves or needles capable of carrying on photosynthesis.
CROWN DOMINANCE refers to the position of a living tree's crown in relationship to the living tree crowns that are adjacent to it. There are four basic crown positions:  1. Dominant - The tree's crown is above the surrounding tree crowns and able to receive full sunlight on all sides.  2. Co-Dominant - The tree's crown is in the upper canopy and at the same levels as one or more of the adjacent trees, The top of the crown receives full sunlight.  3. Intermediate - The tree's crown is below the level of two or more of the adjacent trees, but is not completely over topped. The top of the crown can receive some sunlight when the sun is directly overhead.  4. Suppressed - The tree's crown is below, most of the adjacent trees and can receive no direct sunlight.
CULL is a tree that has no commercial value and never will have.
CUTTING CYCLE is the period of time between harvest cuts in a woodlot or forest.
DEN TREE is a tree which contains one or more cavities that are used by wildlife for dens or nests in which to live and/or rear their young.
DOYLE RULE is a formula for calculating the volume of logs. It was devised by a merchant who lived in what is now upstate New York in the 1700s and who traded goods for furs and logs. Although this rule is not always accurate, it is the accepted rule by which timber is sold in Illinois. Because it underestimates the volume of small logs and overestimates large logs, it has helped to encourage some people to grow their trees to a larger size before selling. The Doyle volume of a log maybe calculated by using this formula:   where "V" is the volume; "D" is the Dib of the log at the small end in inches; and "L" is the length of the log feet.

ECOLOGY is the study of the relationships between animals, plants and their environment.

ECONOMIC MATURITY is that point in time when a tree or stand of trees reaches its maximum economic value, and if allowed to grow beyond that point in time will decline in growth rate, quality or both. Both growth rate and timber quality play a part in determining when economic maturity actually occurs. Example: A black oak tree growing on a poor site with no high quality material in it may be economically mature at 16 inches DBH, while a black walnut tree on a good site with a long veneer quality log might not reach economic maturity until it is 28 inches in DBH or larger.
ENVIRONMENT is all of a plant's or animal's physical surroundings and includes, but is not limited to, the air, soil, water and other living organisms.
FOREST is a plant association predominantly of trees and other woody vegetation.
GROWING STOCK are the good growing, healthy, straight-formed trees that will be kept in the stand to grow to economic maturity. The term "growing stock" is also referred to by foresters as "leave trees."
HABITAT is the area or type of environment where a particular plant or animal normally lives.
HARVEST STOCK are the trees ready to be cut because they are economically mature, badly damaged or of lesser value and should be removed to give growing room to other trees.
MAST is any type of fruit or nut produced by trees or shrubs and eaten by wildlife.
PRESERVATION is the non-use of our natural resources.
PRUNING is a part of timber stand improvement. Trees are trimmed and shaped  to give the best form and most knot-free wood. There are two types of pruning:  1. Corrective Pruning - This is done to shape young trees and develop a straight, central bole while maintaining a maximum growth and crown size.  2. Side Limb Pruning - The trimming of side limbs on the lower portion of the bole to produce a log or logs of knot-free, high quality wood.
RELEASE is a type of timber stand improvement work that can be one of the following:  1. Crop Tree Release - means removing all undesirable competition for sunlight from selected trees so that these trees will grow unencumbered and develop into harvest trees in the shortest possible time. If the trees are less than 16 inches in DBH, one release will not sustain maximum growth to maturity and additional release work will have to be performed.  2. Full Crown Release - means removing all competition for sunlight from the crown of a tree. The degree of crown release is determined by the spacing left between the crown of the tree released and other crowns around it. The greater the spacing, the longer it will be before the crowns grow together and more release is needed.
RESOURCE is anything that is used by people.
NATURAL RESOURCE is anything that is used by people that is naturally present in the environment. This type of resource can be divided into two categories:   1. Non-renewable -Such as minerals and non-living resources that will not reproduce and grow, or will not naturally recycle.  2. Renewable - Such as plants and animals that are living, growing, reproducing or naturally recycling resources.

ROTATION is the period of time it takes to grow a stand of trees to economic maturity.
SAWLOG is a log at least 9 inches in diameter inside the bark at the small end of the log, and usually ranging in length from 8 to 16 feet.
SHADE-TOLERANCE is the ability of a plant to remain in the shade of other plants and still maintain a level of metabolism that will sustain the plant's life. Most of Indiana's high valued species are intolerant to shade. Such species as tulip, black walnut, red and white oak, sycamore, cottonwood, black cherry, pin oak and sweet gum are all intolerant to shade.
SHRUB is a woody, perennial plant that does not attain the height or DBH of a tree.
SILVICULTURE is the science of producing and caring for a forest or woodlot by applying the principles of forest management within a sound economic framework.
SITE INDEX measures the quality of an area for growing trees. Site index is expressed as the average total height a species of tree can grow on the area in 50 years. Example: The site index for tulip tree on an Alford silt loam soil with no erosion is 90 to 105, and for upland oaks on the same soil type is 85 to 90. This means the average tulip tree should be 90 to 105 feet tall in 50 years of growth and the average black, red or white oak should be 85 to 90 feet tall in the same period of time.
STAND is a geographically contiguous parcel of land containing one or more stand types and is usually constructed for administrative reasons.
STAND DENSITY is an expression of the total stocking of a stand of trees and is measured in square feet of basal area per acre.
STAND STOCKING expresses the actual make-up of the stand of trees and is measured in trees per acre (usually broken down by DBH classes).
STAND STRUCTURE is the arrangement of trees in the stand by age.

STAND TABLE is a table of numbers expressing volumes of timber by size classes and species. The unit of volume is usually the board foot, but cords, cubic feet, cord feet, or the weight of wood could be used.
STAND TYPE defines an area of forest land which exhibits similar physical and vegetative characteristics. Such characteristics as forest type, age, size, structure, site class, slope position, aspect, etc.
STAVE is a narrow strip of wood forming part of the sides of a barrel or keg.
THINNING is the reduction in density of stocking by harvesting or deadening trees to prevent overcrowding and stagnation of a stand of trees.  Commercial Thinning - is the reduction in stocking by harvesting trees to be removed for sale or for use. Non-Commercial Thinning - is a part of timber stand improvement work to reduce the stocking by deadening or by cutting, but where no saleable product can be salvaged from the trees to be removed.
TIMBER MANAGEMENT is the manipulation of the forest resource to grow higher quality trees in a shorter period of time on a continual basis. In order to manage a forest you must know what is available (the inventory), how fast it is growing and what the maximum potential for growth is on the site. You must re inventory your resources periodically and readjust your goals according to the new data. Your plan of action must be flexible enough to allow for changes in growth rates and natural disasters. Most forest managers find that growth rates increase when management practices are applied. The highest overall growth rates for any stand on moderate to good sites over the entire rotation period can only be obtained through even-aged management. Natural stands and managed stands have distinctive stand structures identified as even-aged, two-aged and uneven-aged. These classifications are based on age distribution and area.
EVEN-AGED STAND is a stand of trees that are all about the same age on a given area. There are three silvi cultural schemes that can be used to create even-aged stands.  I . Shelter wood - Approximately half to three-fourths of the stand is cut, allowing much more sunlight to penetrate through the upper canopy. This encourages sprouts, advanced regeneration and new seedlings to grow. After the lower story is fully stocked, the remainder of the old over story is removed. This favors intermediately shade tolerant and shade intolerant species to regenerate and develop. Damage done by a second cut could be a draw back. An alternative is to remove the sheltering over story, in two or more cuts, giving more time for tolerant and intermediately tolerant species to develop advance regeneration.  2. Seed Tree - All trees are cut with the exception of approximately one to two trees per acre left for seed. This favors shade intolerant species. Seed trees can be harvested when the new stand is fully stocked. If you have a second cut, the seed trees will probably be lost to natural causes, or removed in T.S.I. work.  3. Clear cutting - The whole stand is cut and the area regenerated. Sustained yield is possible by area control. This favors shade intolerant species. Regardless of the regeneration method applied, the stocking of even-aged stands is maintained during the growing cycle by T.S.I. and/or intermediate cuttings.
TWO-AGED STAND is a stand which has two distinct size classes intermixed:  1. An over story of larger trees, usually pole-size (7" to 12" DBH) or larger, that are definitely dominant and taller than the understory.  2. An understory of small trees that are usually in a suppressed crown position beneath the over story trees and never in a better crown position than co-dominant when there is an opening in the over story.
UNEVEN-AGED STAND is a stand in which three or more distinct age classes are maintained on a given area. An uneven-aged stand is achieved by a combination of intermediate cutting and regeneration harvests.1. Intermediate Cuttings - Treatments conducted to modify or guide the development of an existing crop of trees, and not primarily for regeneration. 2. Single Tree Selection - Individual trees are harvested to provide sufficient area and light for new regeneration. 3. Group Selection - Openings are created in the stand for new regeneration by removing groups of trees. Size of opening will vary with area being managed (usually 1/2 to 5 acres). 4. Diameter Limit Cutting - All trees above a minimum diameter are cut down. This eventually causes a loss of stand vigor because the fastest growing trees are taken first, leaving small, slower growing trees of tolerant species to occupy the growing site. This method of cutting is defined because much of Indiana's forest land has been managed unintentionally in this manner. It is unacceptable because it causes stagnation of the stand and irregular harvests over excessively long cutting cycles.
TREE is a woody, perennial plant which attains the height of 20 feet or higher and a DBH of 4 inches or larger and tends to have a single, central bole.
VENEER refers to thin sheets of wood (1/32" to 1/64") sliced from a saw log of exceptional quality. Veneer is used in plywood manufacturing and as a surface layer application over wood of lesser quality.
WATERSHED is any given area of land which drains or sheds water to the same point. This can be an area of less than an acre, such as one very small ravine draining into a larger ravine, or it can cover millions of acres such as the Mississippi River Basin.
WOLF TREE is a tree that occupies too much growing space for the amount of merchantable volume that it is growing. These are usually large-crowned, short-boled trees that developed in an opening, old field site, or at the edge of the forest where it had little or no competition from other tree crowns while it was developing into a saw log-size tree.
WOODLOT is a small forest.

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