Forestry Glossary Terms

NTRES 6250

Aesthetics

forest value, rooted in beauty and visual appreciation, affording inspiration, contributing to the arts, and providing a special quality of life

Afforestation

The establishment of forest trees by planting or seeding an area not previously forested

Agroforestry

cultivation system combining agriculture and forestry where trees and crops are interplanted

Allegheny hardwood type

a portion of the northern hardwood forest in Pennsylvania, of which black cherry, white ash, and tulip poplar are major components.

Area sensitive species

plants or animals with very specific habitat requirements that are susceptible to population decline when their habitat is altered.

Aspect

the orientation of a slope with respect to the compass; the direction toward which a slope faces; north facing slopes are generally cooler than south facing slopes

Basal Area

a measurement of the cross-sectional area of a tree trunk in square feet at breast height. to find this for the total of a forest stand, add up all trees and is reported as sq. ft. per acre

Biological diversity

the variety of plants and animals, the communities they form, and the ecological functions they perform at the genetic, stand, landscape, and regional levels.

Biological maturity

the point in the life cycle of a tree at which there is no net biomass accumulation; the stage before decline when annual growth is offset by breakage and decay.

Biological simplification

the reduction of biological diversity that results from altering the environment in ways that favor, either directly (i.e., through management) or indirectly (i.e., through pollution), certain species over many others

biomass

the total weight of all organisms in a particular population, sample, or area; biomass production may be used as an expression of site quality.

biome

the largest ecological unit, distinguished by an extensive complex of terrestrial communities, corresponding to a particular climatic zone or region, and associated with an environmental region

board foot

a unit of wood 1 inch thick, 12 inches long, and 12 inches wide. One of these contains 144 cubic inches of wood.

bole

main trunk of a tree

browse (n)

portions of woody plants including twigs, shoots, and leaves used as food by such animals as deer.

buffer strips

forestland left relatively undisturbed to lessen visual or environmental impacts of timber harvesting, usually along a road or waterway.

canopy

the upper level of a forest, consisting of branches and leaves of taller trees. It is complete (or has 100 percent cover) if the ground is completely hidden when viewed from above the trees.

carrying capacity

the maximum amount of animal or plant life that a particular forest environment can support indefinitely without ecosystem degradation, given the limitations of food, shelter, competition, predation, and other available resources; usually expressed in terms of an individual species.

clearcutting

a harvesting and regeneration technique that removes all the trees, regardless of size, on an area in one operation. most often used with species like aspen or black cherry, which require full sunlight to reproduce and grow well, or to create specific habitat for certain wildlife species. produces an even-aged forest stand.

Timberland (commercial forestland)

forestland producing or capable of producing crops of industrial wood (more than 20 cubic feet per acre per year), and not withdrawn from timber utilization

community

a collection of living organisms in a defined area that function together in an organized system through which energy, nutrients, and water cycle.

conservation

the wise use and management of natural resources.

consumptive activities

forest uses which involve the removal of something from the site (hunting, fishing, timber harvesting)

corridor

a strip of wildlife habitat, unique from the landscape on either side of it, that links one isolated ecosystem "island" (e.g., forest fragment) to another.

These allow certain species access to isolated habitat areas, which consequently contributes to the genetic health of the populations involved.

covert

a geographic unit of cover for wildlife (usually game); for example, a thicket or underbrush sheltering grouse or deer.

crop tree

a term traditionally reserved to describe a tree of a commercially desirable species, with the potential to grow straight, tall and vigorously. Now sometimes called “best tree.”

crown class

an evaluation of an individual tree's crown in relation to its position in the canopy and the amount of full sunlight it receives

The four categories are: dominant (D), codominant (C), intermediate (I), and overtopped or suppressed (S).

crown class types

cull

a tree of such poor quality that it has no merchantable value in terms of the product being cut. However, it may have value for wildlife or aesthetics.

dbh

diameter at breast height, or 4.5 feet above ground level. The abbreviation generally is written without capital letters and without periods.

deforestation

the unintentional or intentional conversion of land use from forest to non-forest. Associated with nonrenewable timber harvesting practices.

den tree

a tree with cavities in which birds, mammals, or insects such as bees may nest (also known as cavity tree.)

diameter-limit cut

a timber harvesting treatment in which all trees over a specified diameter may be cut. often result in high-grading

disturbance

a natural or human-induced environmental change that alters one ore more of the floral, faunal, and microbial communities within an ecosystem. Timber harvesting is the most common human made examples. Windstorms and fire are nature made examples

Ecology

the study of interactions between living organisms and their environment

economic maturity

the point in the life cycle of a tree or stand when harvesting can be most profitable, i.e., when the rate of value increase of an individual tree or stand falls below a desired alternative rate of return.

ecosystem

a natural unit comprised of living organisms and their interactions with their environment, including the circulation, transformation, and accumulation of energy and matter.