Forest Glossary

Acre

An area of land measuring 43,560 square feet. A square 1-acre plot measures 209 feet by 209 feet; a circular acre has a radius of 117.75 feet.

Amphibian

Any of a class of vertebrates that regulate their body temperature externally; lay shell-less eggs in wet areas; live in water during early development and live both in water and on land as adults; and use lungs, gills and their skin for breathing. Most have four legs and smooth, moist skin without scales.

Angiosperm

A plant that has true flowers and bears its seeds in fruits. In temperate zones, many angiosperms are deciduous trees, while in tropical zones, many are evergreen trees. Examples include oaks, willows, maples and birches.

Annual Ring

The combination of one earlywood layer (light colored) and one latewood layer (dark colored) seen in a cross-section of a tree. One annual ring usually represents one year of growth.

Artificial Regeneration

The growth of new trees through seeding and planting.

Bark

The tough exterior covering of a woody root or stem that protects the tree from injury caused by insects and other animals, by other plants, by disease and by fire.

Best Management Practice

Forest management practices that reduce erosion and prevent or control water pollution.

Biltmore Stick

A stick similar to a yardstick in appearance, but usually about 25 inches long. One side is scaled to read a tree’s diameter by holding the stick horizontally at arm’s length and against the tree at breast height. A Merritt hypsometer runs along one edge of the stick and is scaled to read a tree’s height from 66 feet away from the tree’s base. These two measurements are then used to find the tree’s volume according to the volume table printed on one face of the stick.

Biodiversity

The variety of life forms in a given area; can be categorized in terms of number of species, variety of plant and animal communities, genetic variability or some combination of these categories.

Bird

Any of a class of vertebrates that regulate their body temperature internally, have bodies that are covered almost entirely with feathers and have forelimbs modified as wings that enable most to fly.

Board Foot

A unit of measure equal to a board that is 1 inch thick, 12 inches long and 12 inches wide, or 144 cubic inches.

Bole

The main trunk of a tree.

Broadleaf

A class of trees that have broad, flat leaves of many different shapes; most are deciduous; also called hardwood because most broad-leaved trees have harder wood than do conifers. Examples include oak, hickory, maple and ash.

Buffer Strip

A narrow zone or strip of land, trees or vegetation bordering an area. Common examples include visual buffers, which screen the view along roads, and streamside buffers, which are used to protect water quality. Buffers may also be used to prevent the spread of forest pests.

Cambium

A thin layer of specialized cells within a tree’s trunk that divide to produce new inner bark cells to the outside and new sapwood cells to the inside. The narrow band of cells that is responsible for the tree’s growth in circumference.

Canopy

The “roof” of the forest formed by the crowns of the tallest trees.

Carrying Capacity

The maximum number of healthy wildlife that a given habitat or area can support without degradation of the habitat.

Cellulose

The scientific name for wood fiber.

Chain

A distance of 66 feet.

Clearcut

A harvesting and regeneration method that removes all trees within a given area. Most commonly used in pine and hardwood forests that require full sunlight to regenerate and grow efficiently.

Clinometer

An instrument that is held at eye level to read stump height and merchantable or total height when standing 50 and 66 feet from the base of the tree. The difference between the two readings yields the height.

Competition

The struggle between trees to obtain sunlight, nutrients, water and growing space. Every part of the tree, from the roots to the crown, competes for space and food.

Conifer

A class of trees that are evergreen, have needle or scalelike foliage and conelike fruit; often called softwood. Examples include pine, hemlock, cedar and cypress.

Conservation

Planned management and wise use of natural resources for present and future generations.

Cord

A standard unit of measure equivalent to 128 cubic feet of round or split wood. A standard cord measures 4 feet by 4 feet by 8 feet. A face cord or short cord is 4 feet by 8 feet by any length of wood under 4 feet.

Cover

(a) Any plant that intercepts rain drops before they reach the soil or that holds soil in place;
(b) a hiding place or vegetative shelter for wildlife from predators or inclement weather.

Crown

The branches and foliage at the top of a tree.

Cruise

A survey or inventory of forestland to locate timber and estimate its quantity by species, products, size, quality or other characteristics.

Deciduous

A group of trees that lose all of their leaves every year.

Decomposition

The process by which organic material such as leaves and branches are broken down by bacteria, fungi, protozoans and the many different kinds of animals that live in the soil.

Dendrology

The study of trees; tree identification.

Diameter Tape

A steel measuring tape that has a scale calibrated to read a tree’s diameter when wrapped around the tree’s circumference.

Diameter at Breast Height (DBH)

Tree diameter measured at 4.5 feet above ground level.

Earlywood

Wood cells produced at the beginning of a tree’s growing season that are generally light in color. Also called springwood.

Ecological Succession

The gradual change of plant and animal communities over time.

Ecology

The science or study of the relationships between organisms and their environment

Ecosystem

A loosely defined area consisting of numerous habitats.

Edge

The transition between two different types or ages of vegetation.

Endangered Species

Any species that has been classified by the U.S. Fish and Wildlife Service or a state wildlife agency as being in danger of extinction throughout all or a significant portion of its range. A species is endangered when the total number of remaining members may not be sufficient to reproduce enough offspring to ensure survival of the species.

Environment

The sum of all external living and non-living conditions and influences that affect the development and survival of an organism.

Erosion

The wearing away or removal of land or soil by the action of wind, water, ice or gravity.

Even-Aged Management

A forest management method used to produce stands that are all the same age or nearly the same age by harvesting all trees in an area at one time or in several cuttings over a short time. This management method is commonly applied to shade-intolerant conifers and hardwoods.

Evergreen

A group of trees that do not lose all of their leaves every year but go through a gradual replacement by dropping only their oldest leaves each year. Instead of being bare in winter, these trees have leaves all year.

Foliage

The leaves of a tree or other plant.

Forage

Vegetation such as leaves, stems, buds and some types of bark, that can be eaten for food and energy.

Forb

Any herb other than grass.

Forest Floor

The lowest level of the forest that is made up of tree seedlings, dead leaves and needles, grasses, ferns, flowers, fungi, and decaying plants and logs.

Forest Management

Caring for a forest so that it stays healthy and vigorous and provides the products and values the landowner desires.

Forest Stewardship Plan

A written document listing activities that enhance or improve forest resources (wildlife, timber, soil, water, recreation and aesthetics) on private land over a five-year period.

Forest Type

A designation or name given to a forest based on the most abundant tree type or types in the stand; groups of tree species commonly growing in the same stand because their environmental requirements are similar. Examples of North Carolina forest types include (a) pine; (b) mixed hardwood; (c) cypress, tupelo and black gum; and (d) oak and hickory.

Forestry

The art and science of managing forests to produce various products and benefits including timber, wildlife habitat, clean water, biodiversity and recreation.

Fuel Loading

A buildup of easily ignited leaves, pine straw, branches and trees on the forest floor.

Group Selection

(a) The removal of small groups of trees to regenerate shade-intolerant trees in the opening (usually at least 1/4 acre); (b) a specific type of selective cutting.

Gymnosperm

A plant whose seeds are not enclosed in flowers. Most gymnosperms produce their seeds on the surface of the scales of female cones and are pollinated by wind. Conifers are the most common type of gymnosperm.

Habitat

An area in which a specific plant or animal naturally lives, grows and reproduces; the area that provides a plant or animal with adequate food, water, shelter and living space.

Hardwoods

Trees with broad, flat leaves as opposed to coniferous or needled trees. Wood hardness varies among the hardwood species, and some are actually softer than some softwoods.

Heartwood

The central core of a tree, which is made up of dense, dead wood and provides strength to the tree.

High-Grading

A harvesting technique that removes only the biggest and most valuable trees from a stand and provides high returns at the expense of future growth potential. Poor quality, shade-loving trees tend to dominate in continually high-graded sites.

Hypsometer

Any device used for measuring tree height.

Increment Borer

A hollow auger-like tool with a screw bit used to remove core samples from trees.

Latewood

Wood cells produced at the end of the growing season that make up the darker section of an annual ring. Also called summerwood.

Limiting Factor

Any requirement for wildlife survival that is in limited supply.

Mammal

Any of a class of higher vertebrates whose bodies are covered with hair, who give birth to live young, nourish their young with milk from mammary glands, regulate their body temperature internally, have four types of well-developed teeth and typically have four well-developed legs with toes that have nails, claws or hoofs.

Mast

Fruits or nuts used as a food source by wildlife. Soft mast includes most fruits with fleshy coverings, such as persimmon, dogwood seed or black gum seed. Hard mast refers to nuts such as acorns and beech, pecan and hickory nuts.

Merritt Hypsometer

A scale that measures the number of 16-foot logs in a tree.

Multiple-Use Management

The management of land or forest for more than one purpose, such as wood production, water quality, wildlife, recreation, aesthetics and clean air.

Natural Regeneration

The growth of new trees in one of the following ways without human assistance: (a) from seeds carried by wind or animals, (b) from seeds stored on the forest floor, or (c) from stumps that sprout.

Naval Stores

Products such as turpentine, pitch and rosin that come from pine trees and are used in the construction and maintenance of wooden sailing vessels.

Phloem

The part of a tree that carries sap from the leaves to the rest of the tree. Also called inner bark.

Photosynthesis

The process by which a plant or tree combines water and carbon dioxide with energy from the sun to make glucose and oxygen.

Plant Succession

The progression of plants from bare ground to mature forest.

Prescribed Burning

The practice of using regulated fires to reduce or eliminate material on the forest floor, for seedbed preparation or to control competing vegetation. Prescribed burning simulates one of the most common natural disturbances. Also called controlled burning.

Pulpwood

Wood used in the manufacture of paper, fiberboard or other wood fiber products. Pulpwood-sized trees are usually a minimum of 4 inches in diameter.

Reforestation

Reestablishing a forest by planting or seeding an area from which forest vegetation has been removed.

Release

To free a tree from competition with its immediate neighbors by removing the surrounding trees. This occurs naturally and artificially.

Renewable Resource

A naturally occurring raw material or form of energy that has the capacity to replenish itself through ecological cycles and sound management practices.

Reptile

Any of a class of vertebrates that regulates its body temperature externally, has dry, glandless skin covered with scales, breathes through lungs and lays large eggs that develop on land.

Resin

A group of sticky liquid substances secreted by plants that appear on the plant’s external surface after a wound.

Roots

The underground portion of a tree that helps anchor the tree in the ground and absorbs water and nutrients from the soil.

Rotation

The number of years required to establish and grow trees to a specified size, product or condition of maturity. A pine rotation may range from as short as 20 years for pulpwood to more than 60 years for sawtimber.

Salvage Cut

The harvesting of dead or damaged trees, or the harvesting of trees in danger of being killed by insects, disease, flooding or other factors in order to save their economic value.

Sawtimber

Wood of large enough size to be used to produce lumber for construction and furniture.

Sedimentation

The deposition or settling of soil particles suspended in water.

Seed Tree Cut

A harvesting method in which a few scattered trees are left in the area to provide seeds for a new forest stand. Selection of seed trees is based on growth rate, form, seeding ability, wind firmness and future marketability. This harvesting method produces an even-aged forest.

Selection Cutting

The periodic removal of individual trees or groups of trees to improve or regenerate a stand.

Shade-Intolerant Specie

Trees that require full sunlight to thrive and cannot grow in the shade of larger trees.

Shade-Tolerant Species

Trees that have the ability to grow in the shade of other trees and in competition with them.

Shelterwood Cut

Removing trees in the harvest area in a series of two or more cuttings so that new seedlings can grow from the seeds of older trees. This method produces an even-aged forest.

Silviculture

The art, science and practice of establishing, tending and reproducing forest stands of desired characteristics. It is based on knowledge of species’ characteristics and environmental requirements.

Site Index

A relative measure of forest site quality based on the height (in feet) of the dominant trees at a specific age (usually 25 or 50 years, depending on rotation length). Site index information helps estimate future returns and land productivity for timber and wildlife.

Snag

A standing dead or dying tree.

Softwood

A tree belonging to the order Coniferales. Softwood trees are usually evergreen, bear cones and have needles or scalelike leaves. Examples include pines, spruces, firs and cedars. See conifer.

Species

A group of related organisms having common characteristics and capable of interbreeding. Loblolly and Virginia pine are common tree species that can interbreed.

Stand

A group of trees that are sufficiently the same in species composition and arrangement of age classes and condition so that they can be managed as a unit.

Streamside Management Zone (SMZ)

An area adjacent to a stream in which vegetation is maintained or managed to protect water quality.

Suppression

The process by which a tree loses its vigor due to inadequate light, water and nutrients.

Threatened Species

Any species that has been classified by the U.S. Fish and Wildlife Service or a state wildlife agency as likely to become endangered within the foreseeable future throughout all or a significant portion of its range. A threatened species has declining or dangerously low populations but still has enough members to maintain or increase numbers.

Transpiration

The loss of water through leaves.

Tree Caliper

A metal or wooden device consisting of an arm and two prongs, one of which is free to slide along a graduated scale on the arm. The prongs are placed against opposite sides of a tree to read its diameter on the scale.

Turpentine

A distilled chemical produced from tapping into a living pine and harvesting the sap.

Understory

The area below the forest canopy that comprises shrubs, snags and small tree. Because the understory receives little light, many of the plants at this level tolerate shade and will remain part of the understory. Others will grow and replace older trees that fall.

Wood

The solid interior of a tree.

Wood Chemicals

Chemicals that are found naturally in the various parts of a tree.

Xylem

The part of a tree that transports water and nutrients up from the roots to the leaves. Older xylem cells become part of the heartwood. Also called sapwood.