Frequently Used Forestry and Natural Resource Terms for Landowners of Oklahoma

A comprehensive glossary of forestry and natural resource management terms based on Oklahoma State University extension materials.

acre

An area of land consisting of $43,560\,\text{square feet}$ in any shape; equivalent to a square $209\,\text{feet}$ on a side, a circle with a radius of $117.75\,\text{feet}$, or $10\,\text{square chains}$.

ad valorem

A property tax assessed as a percent of the appraised value of the property, classified as a management cost in forestry investments.

age class

An interval, commonly $10$ or $20\,\text{years}$, used to divide the age range of trees for classification; for example, a $30\text{-year}$ age class includes trees from $21-40\,\text{years}$ old.

allowable cut

The maximum volume of wood that can be harvested during a given period without exceeding the forest's net growth during that same period.

area-sensitive species

An animal species that requires a large area of continuous, non-fragmented habitat within a similar successional stage.

aspect

The direction towards which a slope faces, which affects site quality and species composition; southerly and westerly aspects are generally drier.

backfire

Any prescribed burn set against the wind to reduce fuels or create a blackline buffer.

basal area

The cross sectional area of a tree in square feet, measured at breast height ($4.5\,\text{feet}$ above the ground).

bedding

A site preparation method in the southeastern United States involving raised mounds for planting seedlings to improve surface drainage.

best management practices (BMPs)

Recommended techniques for timber harvesting and road construction designed to minimize impact on streams, soils, water quality, and wildlife.

biodiversity

The variety of living organisms occurring at three levels: species, community, and landscape diversity.

blue-stain

Discoloration in the sapwood of pine caused by fungi; once considered a defect, it is now used as high-quality interior finish.

board foot

A wood volume unit equaling $144\,\text{cubic inches}$, such as a piece measuring $1\,\text{foot} \times 1\,\text{foot} \times 1\,\text{inch}$.

bole

The main trunk of a tree.

bolt

A short piece of pulpwood, usually ranging from $2$ to $8\,\text{feet}$ in length.

broad-based dip

A surface drainage structure designed to drain water from a road while allowing vehicles to maintain normal travel speeds.

browse

Buds, shoots, twigs, and leaves of woody growth consumed by livestock and wild animals.

buck

The process of cutting a felled log into specified lengths.

butt

The base of a tree or log.

cant

A log that has been squared on two or more sides.

capital gains

Profit from the sale of an asset held for $1\,\text{year}$ or longer; the taxation rate is capped at $28\,\text{percent}$.

catface

A wound on a tree or log typically caused by equipment sideswiping or wildfire.

chain

A unit of distance measurement equal to $66\,\text{feet}$; a section of land is $80 \times 80\,\text{chains}$ square.

chaining

A method of removing brush by dragging a heavy chain between two tractors.

chip-n-saw

A process converting small logs ($7$ to $10\,\text{inches}$ d.b.h.) into cants for lumber and chips for paper.

clearcutting

A harvest and regeneration technique removing all trees on an area in one operation, typically producing an even-aged stand.

clinometer

A hand instrument used to measure tree heights and percent slope.

codominant

Trees with medium-sized crowns receiving full light from above but crowded on the sides.

competition

The struggle among adjacent trees for sunlight, nutrients, water, and growing space.

coppice

A regeneration method where the forest stand grows from stump and root sprouts after clearcutting.

cord

A stack of wood measuring $4\,\text{feet} \times 4\,\text{feet} \times 8\,\text{feet}$ with a gross volume of $128\,\text{cubic feet}$.

corridors

Travel routes, such as streamside management zones, that allow animals to migrate between similar habitat areas.

cost share

Subsidization by government or private agencies for site preparation, reforestation, or timber stand improvement.

crook

An abrupt bend in a tree or log that is considered a defect.

crop tree

A tree selected to be grown to maturity for the final harvest based on its species, quality, and location.

cruise

A forestland inventory assessing the location, volume, species, size, age, and quality of timber.

cull

A tree or log that is unmerchantable because of defects or failure to meet specifications.

cutover

Land that has been previously logged.

deck

A location where logs, pulpwood, or chips are collected and loaded for transport.

defect

An injury or growth characteristic, such as decay or sweep, that decreases the usable wood volume in a log.

den tree

A tree with cavities that provide shelter and protection for wildlife nesting or concealment.

diameter breast height (d.b.h.)

The diameter of a tree measured at $4.5\,\text{feet}$ above ground level on the high side.

diameter limit cut

A harvest removing all merchantable trees above a specified d.b.h., often resulting in high grading.

diameter tape (D-tape)

A tape graduated so that $1\,\text{inch}$ on the tape equals $3.14\,\text{inches}$ of circumference, allowing direct diameter reading.

dibble

A long-handled, tapered spade used to create narrow slits for planting seedlings.

direct seeding

Spreading seeds over a forest seedbed, often via aircraft, to establish a new stand.

discount rate

The minimum annual rate of return acceptable for an investment.

dominant trees

The tallest, most vigorous trees in a stand with well-developed crowns receiving sun on all sides.

Doyle log rule

A log rule that underestimates the volume of small logs and overestimates the volume of large logs.

ecology

The study of plants and animals in relation to their biological and physical surroundings.

ecosystem management

A forest management approach integrating economic, ecologic, and social components.

edge

The boundary where different vegetation types or successional stages meet, attracting diverse wildlife.

even-aged stand

A stand where tree age differences are small, usually within $20\,\text{percent}$ of the rotation age.

feller-buncher

A machine that severs trees, holds them upright, and piles them for transport.

financial maturity

The point when the value growth of a tree falls below the discount rate.

fire-adapted

Plant species or communities that are maintained by or can survive periodic fires, such as shortleaf pine.

firebreak

A natural or constructed barrier used to stop or control the spread of fire.

forest fragmentation

The process of disconnecting forest habitats into "islands" by roads, agriculture, or development.

forest type

A forest class defined by the vegetation currently growing or the site's potential capabilities.

gallery

A burrow excavated by bark beetles in the cambium of a tree for feeding or egg-laying.

girdle

To sever the bark and cambium layer around a tree's circumference to kill it.

group selection

An uneven-aged regeneration method where trees are removed in small groups to establish new age classes.

growing stock

All live trees in a stand, including sawtimber, pulpwood, and seedlings, that continue to grow.

head fire

A fire that spreads in the same direction as the wind.

heavy fuels

Large diameter fuels, like downed logs and logging slash, that burn slowly compared to fine fuels.

herbicide

A chemical preparation used to kill or inhibit the growth of specific plants.

high grading

The practice of harvesting only the best trees and leaving poor-quality trees to dominate the site.

horizon

A layer of soil distinguishable from adjacent layers by physical, chemical, or biological characteristics.

increment borer

A hollow, auger-like tool used to remove a core sample from a tree to determine its age and growth rate.

injection

A method of killing individual trees by applying herbicide under the bark.

intermediate trees

Trees with small, crowded crowns below the general canopy level that receive little sunlight from above.

International log rule

A log rule that assumes taper and is considered the most accurate for estimating tree volume in the southeast.

J-Root

An improperly planted seedling where the roots form a J-shape, often leading to premature death or poor growth.

log rule

A table showing the amount of lumber that can be sawed from logs of different sizes.

lump-sum sale

The sale of specified timber for a set amount of money usually paid in advance.

mast

Nut fruits like acorns and hickory (hard mast) or berries like dogwood and blackberry (soft mast) used as wildlife food.

MBF

An abbreviation meaning thousand board feet.

multiple use

Land management for various purposes including wood, water, wildlife, recreation, and aesthetics.

nonindustrial private forest land (NIPF)

Forestland owned by individuals or corporations not involved in wood processing.

net present value

A financial comparison where all discounted costs are subtracted from all discounted revenues.

opportunity cost

The value of the best alternative forgone by choosing a particular project.

plantation

A forest established by planting, usually consisting of a single species.

precommercial thinning

The removal of submerchantable-sized trees to increase the growth rate of the remaining trees.

prescribed burning

The controlled use of fire to achieve specific forest management objectives.

pulpwood

Wood used to manufacture paper and fiberboard, typically from trees $4$ to $9\,\text{inches}$ in d.b.h.

rotation

The planned number of years between the establishment of a stand and its final harvest.

sanitation/salvage cut

The removal of dead or damaged trees to prevent the spread of pests and promote forest health.

sapling

A small tree usually measuring between $0.6$ and $3.5\,\text{inches}$ in d.b.h.

sawtimber

Trees large enough to yield lumber, usually at least $10\,\text{inches}$ d.b.h. for pine and $12\,\text{inches}$ for hardwood.

seed-tree harvest

A harvest leaving $6$ to $12$ mature trees per acre to provide seeds for a new forest stand.

shade intolerant

Tree species that cannot develop normally in the shade of other trees.

shelterwood cut

A method leaving $30$ to $50$ trees per acre to protect new seedlings, harvested in two or more stages.

silviculture

The art and science of establishing, tending, and reproducing forest stands with desired characteristics.

site index

A measure of site productivity based on the height of dominant trees at $25$ or $50\,\text{years}$ of age.

skidding

The process of dragging trees from the stump to a landing area.

snag

A dead or dying tree used by cavity-nesting animals, preferably at least $10\,\text{inches}$ d.b.h.

species richness

An index representing the total number of different species in a given area.

stocking

An estimation of the number of trees occupying a site relative to the desired number.

streamside management zone (SMZ)

A strip of land maintained along a stream to protect water quality and sensitive areas.

stumpage

The monetary value of trees as they stand uncut in the woods.