Clemson Extension Forestry and Wildlife

Glossary of Forestry Terms

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Absentee Landowner – Landowners who do not live in the county in which their land is located.

Acceptable Growing Stock (AGS) – Trees that are of good form, species, and quality and would be satisfactory as crop trees.

Acid Soils – Soils with a pH value below 7.0. Pines grow well in acid soils with pH values from 5.0 to 6.5. Generally, hardwoods do not grow well in soils with pH values below 6.0. The pH scale ranges from 0 to 14 with values below 7.0 being acidic and values above 7.0 being basic.

Acre – An area of land 209 ft x 209 ft measuring 43,560 sq ft.

Afforestation – The establishment of a stand of trees/forest in an area where there was no previous tree cover.

Age Class – A distinct aggregation of trees that originated at the same time, from a single natural event or regeneration activity or a grouping of trees (e.g. ten year age class) as used in inventory or management.

  • Even-Aged Timber – A timber stand that has very little difference in age for the majority of the trees that make a stand.
  • Uneven-Aged Timber – A timber stand that usually has a visual difference of trees due to the various ages that make up the stand. Typical to be able to identify 3 stages; young regeneration of seedlings/saplings, trees that occupy the understory, and trees that are of mature status.

Alien Species – A species that is not naturally from a particular area, generally a continent. An alien species is the same as an exotic or non-native species, and may or may not be an invasive species.

Allelopathic – Refers to a plant that produces chemicals known to impede seed germination or retard the growth of nearby plants.

Annual Growth Rings – The combination of earlywood and latewood found in a cross-section of wood (such as a stump, log, etc.). The counting of these rings can determine the rough to exact age of a tree, depending on the location of the cross-cut. Some species are easier to see than others.

Aspect – The direction that a slope or landscape feature faces (East, Southwest, etc.).


Bareroot Seedlings – Nursery-grown seedlings that have been lifted from the nursery bed they were raised in, and will not have soil around their roots while being stored and during delivery for planting.

Basal Area (BA) – The given area of land that is occupied by woody stems.  An individual tree’s basal area is the cross-sectional area of a tree measured at 4.5 feet above the ground.  Basal area is also used to determine stocking rates for a given stand.  The sum of basal area for all trees in the stand is the total stand basal area.

Basal Spray – A herbicide application method used to control woody plants by spraying the lower portion of the plants’ bark.

Bedding – Plowing soil with a bulldozed or large tractor into a raised row, in an effort to raise the rows above the water table so prevent root drowning in seedlings.

Best Management Practices (BMPs) – Applied forestry practices that protect or enhance a forest stand. BMPs minimize the impact of forestry/logging activities on water quality, soil erosion, and streamside areas and are managed by the South Carolina Forestry Commission.

Biltmore Stick – A thick wooden ruler used to measure a tree’s diameter and log height. These two measurements can then be used to measure a tree’s board foot volume. A Biltmore stick is a different instrument than a Tree Scale Stick, though they both look similar and measure the same thing.

Biomass – A renewable energy source of biological materials derived from living or recently living organisms, such as wood, waste, and crop residues.

Block – An area of land that has been defined for management purposes. A block can be one single stand of trees or multiple stands all under the same management plan.

Board Feet – Units of solid wood volume equivalent to a 1-foot x 1-foot x 1-inch green and unsurfaced board.  Board foot volume estimates for standing trees contain corrections for the volume of a tree that is lost by sawing a round stem into boards.  1,000 board feet = 1 mbf.

Bole – The main trunk of a tree.

Broad Base Dip – An erosion control practice for roads to disrupt water flow after rains. Soil is scooped diagonally off a road to divert runoff.

Broadcast – To spread or apply pesticides, fertilizer, or seed fairly evenly over an area. Can be done by hand or mechanically.

Bucking – The process of cutting a felled tree into shorter lengths during harvesting operations.

Buffer Strip – A thin strip of land, trees, or herbaceous vegetation bordering or separating an area. Can include visual buffers, streamside buffers, shrub/understory buffers, etc.

Butt – The base of a tree. After the tree has been felled (cut down), the ‘butt’ is located in the first log, which is known as the ‘butt log’.


Cambium – A layer of cell tissue between the inner bark (phloem) and the wood (xylem) that generates new cells annually for the inner bark and wood.

Canopy – The more or less continuous cover of branches and foliage formed collectively by the tops (crowns) of adjacent trees.

Cant – The center section of a sawlog after all the boards are sawn off the sides.

Carbon Sequestration – The uptake of atmospheric carbon dioxide (CO2) by plants during photosynthesis and storage of the CO2 as biomass.

Catface – A major scar on a tree/log/bole left from disease, mechanical, or fire injury.

Certified Forest – A forest that is enrolled in a program (i.e. Tree Farm, Sustainable Forestry Initiative, Conservation Reserve Program, etc.) to promote sustainable forest management.

Chain – A unit of measurement used by foresters to measure distance. 1 chain = 66 feet.

Chain of Custody – The supply chain that wood follows from forest to consumer. Includes, harvesting, transport, processing, manufacturing, storage, and distribution. Allows for wood/fiber used in products to be directly traced to a certified forest.

Chip – A small piece of wood that is used to make pulp, wood composite materials, or wood fuels.

Chip-N-Saw – Cutting lumber from trees between 6 and 14 inches in diameter. The outer layer of the tree is chipped off and the rectangular inner section is cut into lumber. Chip-n-saw mills provide a market for trees smaller than sawtimber but larger than pulpwood.

Choker – A short length of wire cable or chain that forms a noose around the end of a log to be skidded or yarded.

Cleaning – A release operation that removes overtopping trees of similar age to favor trees of better species or quality.  Cleaning is conducted during the sapling stage of stand development. Cleaning typically removes lower value species (locust, sassafras, cedar, sourwood, blackgum, Virginia pine, etc) which become established at the same time as do more valuable oaks, yellow-poplar, ash, and black cherry in old-field stands.

Clearcut Harvest – A harvesting and regeneration method where all trees are removed from a given area. Can be used to have greater control over regeneration and allows for management over the lifetime of the succeeding stand.

Clinometer – A forestry tool used to measure tree height.

Commercial Forest Land – Land deemed suitable for and capable of producing timber crops, usually 20 cubic feet of wood production per acre per year.

Competition (for resources) – The interaction between plants that is a result of limited resources.  For example, species such as oaks and hickories, with their better-developed root systems, are more competitive on sites where moisture is limited.

Conifer – Trees with needles and cones (i.e. pines, hemlocks, fir, cedar)

Conk – The fruiting body of a fungus that extends out of a tree’s trunk.

Conservation – Gifford Pinchot, a turn of the century forester closely associated with President Teddy Roosevelt, applied the word to describe a natural resource philosophy. It meant “wise use.” Through the years it has taken on an extended meaning of “wise use over a period of time.”

Consulting Forester – An independent professional forester working for a company that provides forestland services to the public for a fee or through contracts.

Controlled Burn – See Prescribed Burn.

Contour Map – A map where each line represents a change in elevation.

Coppice – A stand of forest produced from sprouts from stumps or roots of trees previously cut. Many hardwood species sprout and readily coppice when young.

Cord – A unit of measure to describe a stack of wood equal to 128 cubic feet. A cord is usually expressed as 4 feet tall by 4 feet wide by 8 feet long/deep. Historically cords were used to measure for pulpwood and firewood sales, pulpwood has since moved to price/ton.

Cover – The area occupied by vegetation or foliage; vegetation that protects the soil and provides shade to the ground or stream. Usually expressed as a percent.

Crook – An extreme bend in a log or branch, and is looked at as a defect.

Crop-Tree Management – A type of intermediate management that focuses on individual trees of potentially high value.  In most cases, these operations direct the allocation of above and below-ground resources by making more resources available to the residual crop trees.  It is a promising technique to facilitate the production of high-value grade sawlogs.

Crown – The top of the tree where branches and foliage are located

Crown Class – Used to describe a tree’s position in the canopy, relative density, and amount of light obtained. There are 4 classifications, which are as follows:

  • Dominant – Larger, generally older trees that are above all nearby stems. Have full, well-developed crowns that are able to receive light from the sides and from above.
  • Codominant – Large to average-sized trees with developed crowns that form a majority of the upper canopy. There is ample light availability from above but competition for light from the sides.
  • Intermediate – Average to medium-sized trees generally growing below the level of the main canopy, will typically not receive much if any direct light. Generally, these are not good crop trees and will be removed during thinning operations.
  • Suppressed (Overtopped) – small trees that are below the canopy. These receive no direct sunlight. Typically either slower-growing or shade-tolerant species.
  • Crown Closure – When the crown of trees begins to grow together, sunlight hitting the forest floor is greatly reduced and a canopy is beginning to form.

Crown Fire – A fire that spreads across the tops of trees or shrubs independently of a surface fire. Crown fires cannot be effectively or safely fought until the fire drops to the ground.

Crown Thinning – A technique that removes trees from the middle and upper strata of the canopy to favor good trees in the same canopy range.

Cruise – 1. The activity of measuring trees to determine the volume and value of a timber stand by using statistical sampling methods.  2. Can also be in reference to the totals generated from the activity when spoken between two people.

Cull – Any item e.g. tree, log, lumber, seedling, rejected because it does not meet specifications or standards. Often refers to logs that are rejected because of defects – rot, breakage.

Culvert – A structure/device used to channel water. Can be used to pass water underneath a road, railway, trail, or other manmade features.

Cut to length – A system in which harvested trees are cut into log lengths at the stump before they are yarded to the landing; an alternative whole-tree logging.

Coarse Woody Debris (CWD) – Woody material, generally from dead trees, stumps, limbs, or roots; in various lengths and sizes, states of decomposition, and spatial arrangements; positioned at or near the forest floor.


Deciduous – Trees that lose their leaves and go into dormancy.

Deck – Stack of logs – either in the mill or on a landing. Usually sorted by species and size.

Dendrology – The scientific study of trees.

Density – A term used to express stocking amounts in a timber stand.

Den Tree – A living tree with a cavity large enough to shelter wildlife.

Deferment Cutting – A form of two-aged management which is a modification of the shelterwood method that aims to obtain reproduction of shade-intolerant species by reducing the overstory basal area down to approximately 20 – 25 ft.²per acre and to defer harvest of the over wood through a complete rotation of the regeneration.  A sparse stand of large residual trees is left for an extended period, thus mitigating some of the adverse aesthetic effects of clearcutting while maintaining some of the qualities of mature forests, such as hard mast production and roost/den trees. The residual over wood trees ensure a seed source for a long period in case there is difficulty in obtaining regeneration immediately after cutting.

Diameter Breast Height (DBH) – The diameter of a tree measured at 4.5 feet from the ground.

Diameter Tape – A measuring tape that is stretched around the circumference of a tree at DBH to obtain a diameter measurement for the tree.

Dibble Bar – A metal tool used to make an opening/hole in the ground in which to plant bareroot seedlings.

Directional Felling – The skill of felling trees in a desired direction in an effort to protect leave trees and/or aid in easier skidding.

Disking – Tilling of soil with a disk or harrow in an effort to prepare a seedbed for planting or reseeding.

Disturbance – An event (natural or man-made) that disrupts the current forest dynamic and changes the landscape.

Dote – The beginning stages of rot when discoloration and softwood is detected.

Drum Chopping – A mechanical site preparation technique used to break down slash material and vegetation before planting.

Duff – The partially decomposed organic matter of the forest floor beneath the litter of freshly fallen twigs, needles, and leaves.


Earlywood – The portion of annual growth rings that is lighter in color, less dense, and happens during the growing season due to more active growth.

Easement – A right granted to use property by another party in a certain manner.

Endangered Species – Any species of plant, animal, or insect defined through the Endangered Species Act of 1976 as being in danger of extinction throughout all or a significant portion of its range, and published in the Federal Register.

Ephemeral Stream – A stream that typically only flows due to rainfall events and only for a short period of time after the rainfall event.

Epicormic Branching – A tree’s reaction to increased sunlight or stress by sprouting new branches from its bole.

Erosion – The wearing away of the land surface by rain, running water, wind, ice, gravity, or other natural or management actions.

Even-Aged Management – A silvicultural system designed to totally remove an existing stand and create a new single-cohort (age class) stand.  Methods include clearcutting, seed-tree, and shelterwood systems which are used to regenerate shade-intolerant species.

Even-Aged Timber – See Age Class.

Exotic species – A species that is not naturally from a particular area, generally a continent. An exotic species is the same as an alien or non-native species, and may or may not be an invasive species.


Fell – The act of cutting a tree down.

Feller Buncher – A large piece of forestry equipment used to cut down trees from its stump, collect that tree, move them to the next tree, and cut it down as well. The machine is felling and bunching before it lays the trees down in a bundle.

Fiberboard – A wood product manufactured from wood fibers combined with synthetic resins or other binders, and compressed into panels in a hot press.

Fire Scar – Damage/injury/wound at the base of a tree caused by fire.

Firebreak – the removal of fuel to aid in stopping a fire. Can be manmade (a road or by using a plow to expose bare soil) or natural (such as a river or a lake). See Fuelbreak for manmade applications.

Ford – A stream crossing where rocks have been placed to line the streambed in an effort to be driven over.

Forest – An ecosystem characterized by a more or less dense and extensive tree cover, often consisting of stands varying in characteristics such as species composition, structure, age class, and associated processes, and commonly including meadows, steams, fish, and wildlife. Forests include special kinds such as industrial forests, non-industrial private forests, public forests, urban forests, and parks and wilderness. Forests differ in their biological composition, management goals and objectives, and the laws and regulations governing them.

Forest Floor – Refers to the layer in a forest that is the top of the ground.

Forest Health – A subjective observation of the condition the forest is on based on growth, age, diversity, wildlife, lack of pests, etc., and how it plays into management objectives.

Forest Inventory – Another name for a forest cruise. Forest inventory is the summation of timber sizes and species to arrive at a better understanding of what is present. This will aid in making management decisions.

Forest Management – The application of scientific principles of forestry to a forest in effort to arrive at a desired goal/outcome.

Forest Product – Any raw material yielded from a forest.

Forest Stand Improvement – See Timber Stand Improvement.

Forest TypeA category of forest defined by its vegetation, particularly the dominant vegetation as based on percentage cover of trees.

Form – A term used to describe a tree/log’s taper from being a perfect cylinder.

Form Class – The measure and classification of a tree’s taper as a grouping. The measurement is at 17.3 feet above the ground and it is expressed as a percentage. The higher the number, the less taper (or less loss of wood at the other end of the log).

Fragmentation – The break-up of one continuous piece of habitat/woods into smaller pieces either by natural disturbance or by man.

Frost Heave – When soil near the surface is lifted due to the freezing of soil moisture, thus causing seedlings to rise as well.

Fuelbreak – A generally wide (60 to 1000 ft.) strip of land on which native vegetation has been permanently modified so that a fire burning into it can be more readily controlled. Also, see Firebreak.


Germination – The beginning of the growth of a mature seed, spore, or pollen grain; the development of a seedling from a seed.

Girdling – Completely encircling the trunk of a tree with a cut that severs the bark and cambium of the tree. The purpose is to stop the flow of nutrients and water to kill the section above the girdling cut. Herbicide can sometimes be injected into the cut to ensure the death of the tree.

Grading – Evaluating trees/logs/lumber based on quality.

Ground Fuels – Material (leaves, twigs, limbs, logs, vegetation, etc) on the forest floor that is considered to be combustible in the event of fire (controlled burn and/or wildfire).

Group Selection – An uneven-aged management method in which larger openings are created than in single-tree selection.  The method favors the regeneration of intermediate and shade-intolerant species.  The opening size created during harvesting is a diameter less than twice the height of the tallest trees (approximately one-half an acre or so).

Growing Stock – Refers to all the trees growing in a stand, expressed by basal area and/or volume.

Growth Ring – The combination of latewood and earlywood that a tree adds each year. Typically thought of as the annual latewood ring (dark-colored section) one would count to determine a tree’s age.


Hack-N-Squirt – Where an axe or hatchet is used to make ‘hacks’ into the tree’s cambium layer. A plastic ‘squirt’ bottle is then used to spray a specific amount of herbicide into the cuts.

Hardpan – A layer down in the soil below the surface where soil compaction has made the soil difficult for roots to penetrate any deeper.

Hardwood – A term used to describe deciduous broadleaf trees such as oaks, hickories, maples, poplars, elms, etc.

Harvest – The removal of marketable products or materials from the forest.

Heart Rot – The decay of heartwood which is located in the center of the tree.

Heartwood – The center, inner core, of a tree that is typically darker due to it being made up of non-living wood cells.

Heel-In – Temporary planting of seedlings by covering their roots with soil in an effort to keep them alive until ready to be permanently planted.

High-Grading – The practice of cutting the best and most desirable trees and leaving scattered poor quality and unmerchantable residual trees.  If repeated over and over, high-grading will essentially leave stands of trees with low growth potential and can ultimately lead to an impoverished condition where few good management alternatives remain.

Humus – Another term for organic matter.


Improvement Cutting – The elimination or suppression of less valuable stems in favor of more valuable tree growth, typically of mixed or uneven-aged forests.  It is an intermediate management technique designed to improve stand quality.

Impoverished Stands – Poorly managed stands in the central hardwood region that have become depleted either through repeated high-grading, fires, animal damage, or pest attacks.

Incentive Programs – Local, state, and federal government agencies and private organizations will offer financial assistance/incentives for certain management activities carried out on one’s land. Assistance can be for single time management or for a longer-term management approach.

Increment Borer – A hollow tool used to bore into a tree to extract a core of wood in an effort to count the growth rings to determine a tree’s age.

Industrial Forests – Forest land owned by a company or individual managed primarily for wood products. The owner may or may not operate sawmills or other wood-using plants.

Integrated Pest Management (IPM) – The combining of appropriate pest control tactics into a single plan to reduce pests and their damage to an acceptable level.

Intermittent Stream – Streams that have a defined channel and flow for as long as water is available, be it from rain or abundance of groundwater.

Invasive Species – This is a species not from an area, generally a continent, that also displaces native species and causes economic or ecological damage. Invasive species are alien, exotic, or non-native species, but not all alien, exotic, or non-native species are invasive.


J-Root – When a seedling has been improperly planted and its root is in the shape of a ‘J’. Typically seen when seedlings are ‘stuffed’ into a planting hole.

Juvenile Wood – Typically considered to be the wood grown by a tree in the first 15 years of its life. The nature of the wood cells tends to lend this wood a lesser quality when compared to wood grown later in the life of the tree. Most trees do not have a clearly defined zone of transition to mature wood.


Kerf – The width of wood taken by the saw blade when a cut is made.

Knuckle-Boom Loader – A large piece of forestry equipment that is basically a crane with a grapple/claw used to load log trucks.


Ladder Fuels – Combustible material that provides vertical continuity between vegetation strata and allows fire to climb into the crowns of trees or shrubs with relative ease. Ladder fuels help initiate and sustain crown fires.

Landing – See Yard, also known as Log Landing or Loading Deck.

Latewood – Wood that is grown during the later part of the year that shows up as the dark section within the annual growth ring.

Litter – Often meant as leaves, twigs, organic matter on top of soil, and/or the uppermost portion of soil that is still in the early decomposition stage.

Live Crown Ratio (LCR) – Expressed as a percentage, LCR is the ratio of the height of the crown in relation to the overall height of the tree. Example: A 100 ft. tall tree with a crown height of 40ft. Would have a live crown ratio of 40%.

Log – The stem of a felled tree, trimmed of limbs, cut to preferred lengths for final products. e.g. 16.5 ft or 33 ft for lumber that will eventually be sold in 8 ft lengths. The extra 0.5 or 1.0 ft is called trim allowance and compensates for log end damage and sawmill processing.

Loading Deck – See Yard, also known as Log Landing/Landing.

Log Rules – A table showing estimated amounts of lumber that can be sawed from logs of given lengths and diameters. Log rules are commonly used:

  • Doyle Rule – A simple formula rule used in the eastern US. It underestimates the amount of lumber in smaller logs and overestimates larger logs.
  • International 1/4-inch Rule – A formula rule allowing ½ inch taper for every 4 feet of length and 1/16 shrinkage for each 1-inch board. This measure approximates the actual sawmill lumber tally.
  • Scribner Rule – Based on a series of diagrams outlining the sawing pattern for 1-inch lumber for each diameter and length class with a 1/4-inch allowance for saw kerf. Taper is not accounted for in the rule, so it under-estimates volumes for logs more than 16 feet in length.

Log Scale – The lumber contents of a log. Determined by a log rule.

Logging Deck – See Loading Deck.

Logging Slash – Wood debris that was not used to make a wood product and are left on the forest floor to decompose to add nutrients to forest soils.

Low Thinning – Also known as thinning from below.  The method involves the removal of trees from lower canopy positions (overtopped, intermediate, or weak co-dominants crown classes).  The primary objective is to salvage anticipated losses due to natural mortality from shading.

Lumber – The sawn product from a tree; solid-wood dimension lumber as opposed to peeled for plywood, or chipped for reconstituted wood products like oriented-strand board or fiberboard.

Lump-Sum Sale – When a timber buyer and seller agree on a price for the timber (trees to be thinned and/or clearcut as designated) and is paid in full prior to harvesting.


Marking Timber – The process of identifying a tree and marking (typically with paint) before a harvesting operation. Marked timber can be ‘marked to cut’ or ‘marked to leave’ and is usually up to the discretion of the forester performing the marking activity.

Mast – The fruit of forest trees (can be acorns, nuts, as well as fleshy fruits) that serve as a food source for many species of wildlife.

Mature Forest – A term used to describe a forest that has reached a point where annual growth is slowing at a rate that the economic sense tells us it is time to cut to maintain a good rate of return.

Mature Tree – A tree that has reached its maximum growth or height or has reached merchantable product size.

MBF – An abbreviation for 1,000 board feet.

Merchantable – Trees that have grown to meet at least a minimal size to be used as a particular wood product.

Merchantable Height – The marketable length of a tree to a minimum diameter top, merchantable top diameter.

Mesic – An environment or habitat containing a moderate amount of moisture.

Microclimate – An area that exhibits localized differences in the trees, vegetation, soils, habitat, and/or atmospheric when compared to surrounding areas.

Midstory – A layer of trees and/or vegetation between the understory (low growing plants) and the overstory trees in a forest.

Monoculture – A vegetative type that consists of only one species.

Monoecious – Plants that have male and female flowers on the same plant.

Multiple Land Use – The management of land and forests for timber, wildlife, water, and recreation in an integrated and comprehensive program.


Native Species – A species naturally from a particular area, generally a continent.

Natural Regeneration –Tres that become established by natural ways, such as seeding or sprouting.

Natural Thinning – The inherent process occurring in stands by which the thousands of seedlings and/or sprouts per acre in the original stand are gradually reduced in number over time as a result of plant competition.

Non-Industrial Private Forest (NIPF) – Forest land that is privately owned by individuals or companies other than the forest industry and where management may include objectives other than timber production.

Non-native species – A species that is not naturally from a particular area, generally a continent. A non-native species is the same as an alien or exotic species, and may or may not be an invasive species.

Noxious Plant – A plant that is designated by law as being especially undesirable and ecologically damaging.


Old Growth ForestThe late successional stage of forest development, usually characterized by large, old trees; standing dead trees, snags; closed or dense canopy conditions; and down logs and coarse woody debris. Old-growth forest is incorrectly commonly perceived as an uncut, virgin forest with very little human-caused disturbance.

Organic Matter – Material produced by and/or having come from plants and animals that can decompose and incorporate into the soil.

Overrun – The excess lumber from a low that exceeds the log scale estimate.

Overstocked – A forest stand with too many trees present for optimal tree growth.

Overstory – That portion of the trees, in a forest of more than one story, forming the upper or upper-most canopy layer.

Overstory Removal – Removal of trees in dominant or codominant positions to release understory trees or vegetation.


Pay-as-Cut Sale – See Per Unit Sale.

Perennial Stream – Streams that have well-defined channels and typically flow year-round under normal weather conditions.

Per Unit Sale – When a timber buyer and seller agree on a price based on units (typically tons, MBF, cords) for wood sizes intended for certain wood products and is paid by the total cumulative number of units cut.

Pesticide – A pesticide is any substance used to kill, repel, or control certain forms of plant or animal life that are considered to be pests.

Phloem – The vascular tissue in plants that conducts sugars and other metabolic products downward from the leaves.

Photosynthesis – The process where a plant’s leaves make food for the plant (sugar) by using sunlight, water, and air while converting carbon dioxide (CO2) into oxygen (O2).

Pilings – See Poles as pilings are very similar. However, pilings are chemically treated differently than poles due to the marine environment they are intended to be used in.

Pioneers – The first trees to establish themselves on ground that was abandoned or newly disturbed.

Planting – The physical action of placing a seed or seedling into the ground.

Plantation – A stand established by planting trees typically in rows.

Plot – An area where a forester samples the trees to collect data. Multiple plots add together to make a cruise.

Poles – A product class ranging from approximately 10”-24” DBH and over 30’ tall with a top diameter greater than 6” and to be free of defects. They are generally thought of as being the highest valued stems in a forest due to their rarity.

Pre-Commercial Thinning – Cutting/deadening trees due to stand density being too high, in an effort to increase the growth rates of remaining trees during a time when trees are too small to have a commercial value.

Preparatory Cutting – Also referred to as a seed cutting which is a shelterwood cutting treatment designed to remove poor-quality trees and increase vigor and seed production among the residual trees.

Prescribed Burn – The controlled use of fire to achieve forest management objectives. Can be used to reduce hazardous fuel levels, improve wildlife habitat, site preparation for planting, control unwanted vegetation, improve habitat for desired vegetation, and improve visibility/access within the stand that is burned.

Preservation – To protect an area from treatment or management. The meaning stems from 19th-century land reserves wherein areas and resources were set aside for limited or restricted use and development. Preservation often restricts land uses to recreation or scientific study.

Pruning – The removal of live or dead branches from standing trees.

Pulpwood – Trees of a species, size, and quality that, when harvested, would be processed into pulp.  Pulpwood trees are typically too small in size, of an undesirable species, or contain too many defects (such as crookedness or knots) to be sawn into boards.

Punky – A spongy wood condition that is caused by wood decay.

Pure Stand – A stand with the majority of trees in the upper crown class being of the same species


Rake and Pile – A mechanical site preparation method where slash material is raked into a pile.

Recruitment – The process of younger trees growing into the next larger size class.

Reforestation – Re-establishment of a forest in an area where the previous forest has been removed.

Regeneration – The process of establishing young trees, either artificially or naturally.

Release Cutting – Cutting of inferior trees to promote the growth of desired young trees by elimination competition.

Reproduction – All seedlings/saplings within a forested area.  In closed-canopy stands, most reproduction will be shade-tolerant species such as American beech, eastern hophornbeam, maples, blackgum, hickory, etc.  Shade intolerant species (yellow-poplar, ash, black cherry, etc) require higher light levels to advance in growth.  Some form of stand manipulation/disturbance is required to develop the favored shade-intolerant reproduction. Seedlings/sprouts 0-1” DBH.

Reseeding – The action of plants dropping seed in order to regenerate.

Residual Stand – The portion of trees remaining after any partial cut or thinning.

Riparian – The area of land along stream/river banks and lakesides that is typically protected from forestry activities with buffers.

Rip-Rap – Rock or other large material (such as broken concrete) used on slopes susceptible to erosion due to water.

Roller Chop – See Drum Chopping.

Root Collar – The zone where the stem of a tree turns into roots.

Rotation – The number of years needed to grow trees from one size/wood product to the next larger size due to wood product specifications.

Roundwood – Wood products that are round, such as posts, pilings, poles, etc.


Salvage Cut – A harvest in which dead or damaged trees or trees at risk of premature mortality (from disease, insects, weather events, or other factors) are cut to save their value and to preserve forest health. Also known as sanitation cutting.

Sanitation Cut – A precautionary harvest method used to prevent loss from damage due to conditions and/or the presence of insects and/or disease.

Sapling – A small, typically younger, tree between 2 – 4 inches in diameter.

Sapwood – The light-colored part of a tree’s woody stem between the heartwood and bark. Also called Xylem.

Saw Kerf – see Kerf.

Sawlog – A log large enough, and with 2 clear sides running the length of the log, to produce dimensional lumber products.

Sawtimber – Trees in a forest large enough to produce sawlogs.

Scaling – Measuring logs to determine the volume within.

Scalping – A mechanical site preparation method where the sod layer is peeled back to expose bare soil for reforestation efforts to aid in the competition between grass/vegetation and seedlings being planted. Typically in old field situations, especially with longleaf pine.

Scarify – To disturb the forest floor to encourage regeneration by scratching or cutting back the surface.

Seedbed – A place where the soil has been prepared to encourage ground to seed contact to aid in germination. Seedbeds can be prepared naturally and artificially.

Seedling – A tree grown from seed, less than 3 ft. tall or 1 in. DBH.

Seed Source – The location that the seeds came from. Can describe a geographic area or an individual tree.

Seed-Tree Cutting – An even-aged silvicultural system involving the removal, in one cut, of mature timber from an area, save for a small number of seed bearers left singly or in small groups.  Seed trees are usually wind disseminated species such as yellow pines and yellow poplar.

Selection Harvest – A term used to describe a thinning method when managing uneven-aged stands to harvest the chosen trees.

Shade-Intolerant – Trees that cannot survive/thrive underneath the shade of larger dominant trees

Shade Tolerance – A tree’s capacity to develop and grow in the shade of and in competition with other trees. Trees are classified ranging from very tolerant to very intolerant.

Shearing – A mechanical site preparation technique used to move wood material (both standing and slash) after a clearcut. Typically performed by a bulldozer with a purpose-built blade attached.

Shelterwood – An even-aged management system where the objective is to develop a standing crop of advanced regeneration in the understory through a series of partial removal cuttings of the overstory/midstory. The system relies on natural reproduction, but in some cases, artificial regeneration (seedling planting or direct seeding) is used as a primary or supplemental source of regeneration.  The shelterwood method is especially well suited to regenerate species that are intermediate in shade tolerance and have slower initial growth (such as oaks).

Silviculture – The art and science of managing (through establishment, cultivation, and reproduction) forestland for desired characteristics through the use of knowledge, experience, and modern scientific data.

Silvopasture – The practice of grazing cows and other livestock animals under and amongst a forest. Typically the forest is of low enough stocking and/or strips of trees to promote vegetation growth to support grazing.

Single-Tree Selection – An uneven-aged management method based on the removal of single merchantable trees.  A proportion of varying individual diameter size classes is removed. This technique stimulates the natural gap dynamics that occur in mature unmanaged natural stands. The method leaves relatively small canopy gaps that can close fairly rapidly due to crown expansion of residual trees thus promoting the regeneration of shade-tolerant tree species.

Site – The area in which a plant or stand grows, considered in terms of its environment, particularly as this determines the type and quality of the vegetation the area can support.

Site Class – A measure of the quality of a site and the potential to produce trees.

Site Index – Describes the potential growing productivity for a given species of tree for a particular location.  Numeric value indicates the estimated height that trees of a given species are expected to reach by either age 25 or 50.

  • Example:  Site productivity is estimated to be 90 feet for yellow poplar at base age 50.  This is a highly productive site.  A poor site would be a value of 65, base age 50, or less.

Site Preparation (Site Prep.) – The process of preparing an area for the establishment of a forest. This can include, but is not limited to, mechanical manipulation, chemical control, burning, soil tillage, etc.

Site Quality – The collective factors to determine the productivity potential of a forest on a particular site and will be expressed as a volume.

Size Class – Designation of standing trees based on DBH.

  • Seedling – A tree growing from a seed source that is less than 1” in diameter and usually shorter than DBH.
  • Sapling – A small tree that is 1” – 3” at DBH.
  • Pulpwood – A tree 6” – 12” at DBH. Sometimes referred to as ‘poles’ in other parts of the country.
  • Sawtimber – A tree 12” at DBH or greater to saw lumber from.
  • Poles – In the south, the term poles is meant as large straight trees that are used to make telephone poles, bridge pilings, etc.

Skid Roads – (Skid Trail) A road/trail in the forest used to drag trees/logs to the loading deck using heavy equipment.

Skidder – A large piece of forestry equipment used to drag trees/logs to a loading deck. The skidder is what moves the trees after the feller buncher has cut them down, once the trees arrive at the landing, the knuckle-boom loader loads them on the truck.

Skidding – The act of dragging fallen trees along the forest floor during a harvesting operation.

Slash – The residue, branches, bark, tops, chunks, cull logs, uprooted stumps, and broken or uprooted trees left on the ground after logging; also large accumulations of debris after wind-throw or fire.

Slope – The incline of a hill to express the change in elevation.

Slope Position – A particular location on a slope as upper, middle, or lower slope; ridgetop; or bottomland. A specific topographic location.

Snag – Standing dead trees, which provide wildlife habitat. They also will provide large organic debris (LOD) or large woody debris (LWD) when they rot and fall. The “LOD” retains moisture and provides habitat to many species of insects, fungi, and plant life.

Softwood – A term used to describe conifers, such as pines, spruce, hemlock, fir, etc.

Soil Horizons – Distinct layers of the soil that differ in properties; usually seen in color and/or texture changes.

Soil Texture – The proportions of sand, silt, and clay that make up the soil.

Southern Yellow Pine – A grouping of pines (loblolly, slash, shortleaf, Virginia, etc.) that are native in the southeast.

Species – A group of organisms that exhibit similar traits and characteristics and can freely interbreed.

Species Composition – All species within a forest that collectively make up the diversity of the forest.

Sprout – A tree originating from a root or stump.

Stand – A group of trees with similar age structure, species composition, site quality, and condition so as to be recognizable from adjacent stands.  It is the basic unit of the forest to which a silvicultural treatment is applied.

Stand Density – A measure of the stocking of a stand of trees based on the number of trees per area and diameter at breast height (DBH).

Stand Density – A measure referring to stocking/crowding of trees in a stand often expressed through BA, TPA, or volume per acre.

Stand Growth – A noticeable change in stand volume and/or growth.

Stand Improvement – A forest management practice designed to manipulate the standing trees through harvest, etc to encourage desirable species to grow in an effort to meet management0 objectives.

Stocking – Refers to a stand’s trees per acre while taking into consideration the size of the trees standing.

  • Overstocked – A stand that is crowded with competing vegetation/trees and usually reduces growth.
  • Fully Stocked – A stand that has a good mix of trees occupying space yet not crowding adjacent trees which will allow for future growth in size (diameter and height).
  • Understocked – A stand where trees are not occupying all the available space and the trees may exhibit undesirable growth characteristics due to excessive available sunlight.

Stocking Rate – Classification system to describe growing conditions within a forested stand.  An overstocked stand contains an excessive amount of trees which inhibits volume/individual tree growth.  An understocked stand contains too few trees to maximize both volume production and stem-form within a forested area.  Moderate or fully stocked conditions are most favorable.

Streamside Management Zone (SMZ) – A strip of land adjacent to a water body or stream channel where soils, organic matter and vegetation are managed to protect the physical, chemical, and biological integrity of surface water adjacent to and downstream from forestry operations. An SMZ also may be called a “filter strip “ or “buffer zone.”

Stumpage – The value of the timber while standing in the forest. Different stumpage prices are assigned to timber due to variability in species, size, quality, and markets.

Subsoiling – Tillage of soil in an effort to fracture a hardpan and/or soil compaction to promote root growth for tree survivability and tree growth, typically in old agricultural fields being converted to forests.

Succession – The process of one plant community changing into another plant community as a response to out-competing its predecessor.

Surface Fuels – The loose surface litter on the soil surface, e.g., fallen leaves or needles, twigs, bark, cones, branches, grasses, shrub and tree reproduction, downed logs, stumps, seedlings, and forbs interspersed with or partially replacing the litter.

Sustainable Forestry – Forest management that meets the forest resource needs and values of the present without compromising the similar capability of future generations. The stewardship and use of forests and forest lands in a way and at a rate that maintains their biodiversity, productivity, regeneration capacity, and vitality now and in the future. Sometimes pitted against timber management, casting the latter as single purpose and unsustainable.

Sustained Yield – Management of a forest stand to provide a continuous supply of timber and revenue while protecting public trust resources of water, watersheds, wildlife, air quality, soil productivity.


Taper – The amount of diameter reduced from one end of a cylinder (log) to the other end.

Thinning – A cutting or killing of trees in an immature forest stand to reduce tree density and concentrate the growth potential on fewer, high-quality trees.

Threatened species (T&E) – A plant, animal, or insect species likely to become endangered throughout all or a significant portion of its range within the foreseeable future.

Timber – Forests and stands containing timber; wood, other than fuelwood, potentially usable for lumber.

Timber Market – A term used to refer to the demand for, and supply of timber.

Timber Sale – Activities dealing with the exchange of timber from one party to another. Two common sale methods are:

  • Lump sum – A specified area or volume of standing trees is sold for a cash price before cutting.
  • Unit  sale – The buyer pays a specified amount for each unit of timber cut.

Timber Stand Improvement (TSI) – A thinning made in immature stands to improve the composition, structure, condition, health, and growth of the remaining trees, while also increasing sunlight to the forest floor to promote regeneration. Often referred to as Forest Stand Improvement.

Tree – A woody perennial plant, typically large with well-defined stem or stems carrying a definite crown of branches and leaves.

Tree Farm – A privately owned forest property that is registered through the American Tree Farm System. In years past, tree farms’ main goal was timber production and timber revenue. Present-day efforts now also include water quality, way of life, and recreation.

Trees Per Acre (TPA) – Refers to the number of trees on a per-acre basis in a specified stand or forest; a useful measure of forest or stand densities and stocking levels.

Tree Scale – A scale used to estimate lumber board foot volume in a standing tree.

Tree Scale Stick – A wooden tool resembling a yardstick that is calibrated to measure a tree’s diameter and height.


Undercut – The notch cut in the tree trunk to regulate the direction of the tree’s fall.

Understory – The layer formed by grasses, shrubs, and small trees under the canopy of larger trees and plants.

Uneven-Aged Forest – A forest with more than two age classes of trees present. An age class is 20 years.

Uneven-Aged Management – Silvicultural system that produces uneven-aged (multi-cohort or age classes) stands of shade-tolerant species.  Single-tree selection and group selection methods are forms of uneven-aged management.

Urban Sprawl – The expansion of the human population into areas that were previously undisturbed or considered to be rural areas. Urban sprawl typically converts farms and/or forests into developed areas (buildings, homes, etc.).


Veneer Logs – Logs that will be cut into thin sheets to make veneer for manufacturing plywood, paneling, or furniture. Logs must be high quality and a minimum of 12 inches in diameter. Logs larger than 12 inches are preferred.

Virgin Forest – An imprecise term suggesting a forest has never been influenced by man and/or man’s activities.

Volume – The amount of wood in a tree, stand of trees, or log according to some unit of measurement, such as board foot, cubic foot, etc.

Volume Table – A table that estimates the volume of wood contained in a standing tree based on measurements f the tree, most commonly DBH and merchantable height.


Water Bar – The portion of a dirt road where the soil is formed as a raised bar across the road that diverts surface water runoff and prevents soil erosion. Properly constructed bars allow vehicular traffic.

Watershed – An area of land that concentrates water into a single stream through topographical features.

Wedge Prism – A small glass wedge tool that is used to calculate basal area in a plot.

Weeding – A release operation performed in seedling stands to remove herbaceous plants and shrubs that overtop desirable tree seedlings.  Also commonly referred to as a seedling release treatment.

Wetlands – Swamps, drains, marshes, supersaturated soils, etc. that offer habitat for numerous wildlife species, can be nutrient-rich, and protect against severe floods.

Whole Tree Harvesting – A harvesting method where the entire tree is utilized, typically chipped for pulpwood or biomass fuelwood.

Widowmaker – A limp, top, leaning tree, dead tree, or other material large enough to fall without warning with enough force to cause injury and possibly death.

Wildfire – Fires burning out of control regardless of how or why they were started.

Wilderness – In the strictest sense, this means that an area that has never been developed by man.

Windrow – A row of piled slash typically left after a clearcut in an effort to move material out of the way for replanting efforts, as well as wildlife habitat.

Windthrow – (Blowdown) An area of trees blown over by high winds.

Wolf Tree – A very large, often mature tree that is or was open-grown. Will have a wider shape and form as opposed to the more straight and narrow form of trees grown with competition for light in their vicinity.

Wood Pulp – Mechanically ground or chemically digested wood separated into individual fibers and used to manufacture paper and fiberboard products.


Xeric – An environment or habitat containing little moisture; very dry.

Xylem – The vascular tissue in plants that conducts water and dissolved nutrients upward from the root and also helps to form the woody element in the stem.


Yard – (Landing) Refers to the area in a forest where tree trunks are stacked for sorting. Yards are also places where the wood in the form of logs, pulpwood, and other forest products are collected and stored prior to transport or processing.

Yarder – A machine or system of winches used with a tower and cables to haul logs to a landing

Yield Table – A tabulation of volume per acre found in full stands on specified sites at specific ages.


Stephen Pohlman, Cooperative Extension, Forestry and Wildlife Agent

This information is supplied with the understanding that no discrimination is intended and no endorsement of brand names or registered trademarks by the Clemson University Cooperative Extension Service is implied, nor is any discrimination intended by the exclusion of products or manufacturers not named. All recommendations are for South Carolina conditions and may not apply to other areas. 

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