Forestry General Knowledge

Acre

Ten square chains, or 208.7 ft. by 208.7 ft. square, or 43,560 square ft.

Afforestation

Establishment of a forest or stand in an area not previously forested.

Age-Class

Classification of a stand of trees based on when regeneration started.

Rotation-Age

Age at which a tree is ready to harvest.

Annual Ring

A summer and spring ring representing one growth year.

All-Aged

A stand of timber where all age classes are represented.

Aspect

Direction the slope faces.

Azimuth

Three hundred sixty (360) degrees on compass.

Back-Fire

Fire set along a control line which burns back into the fire.

Inner Bark

Area between the cambium and periderm.

Outer Bark

Layer of tissue outside of the last periderm layer.

Bearing Compass

A compass set up with four (4) 90 degree quadrants.

Tree Biomass

Weight of complete trees (living material).

Board Foot

The volume equivalent to a board one inch thick x twelve inches wide x twelve inches long.

Bole

Trunk or stem of a tree.

Breast Height

A point on a tree 4.5 ft. above the ground on the uphill side of a tree.

Controlled Burning

A deliberately started fire to accomplish a particular management purpose.

Burning Prescription

Describes the conditions and results to be garnered from a control burn.

Buck

To cut logs into specific lengths.

Butt Log

The first log above the stump.

Cambium

Growing tissue, produces xylem and phloem, that is part of the inner bark.

Chain

66 ft. measurement unit, or four (4) rods long.

Chaparral

A thicket of low, evergreen oaks or dense tangled brushwood.

Season Check

Lengthwise separation of wood which goes or extends across the rings of annual growth and is caused by stress during seasoning.

Clearcutting

Area in which the entire timber stand has been cut.

Codominant

Trees which are the average level of the canopy and receive light on the top but not necessarily on all sides of the crown.

Conifer

Cone bearing trees, usually evergreen.

Cord

Unit of measurement for stocked wood, four ft. by four ft. by 8 ft.  (4’ x 4’ x 8’) or 128 cubic feet.

Crown

The part of a tree or woody plant bearing live branches and foliage.

Crown Fire

Fire which has moved into the tops of the trees.

Cruise

Survey of forest lands to locate and estimate volume and grades of standing timber.

Cubic foot

A unit of true volume that measures 1 x 1 x 1 ft or the equivalent of 12 board feet.

Cunit

A unit of volume, usually pulpwood, that measures 100 ft3.

Cull

Any item of production, e.g., trees, logs, lumber, or seedlings, rejected because it does not meet certain specifications of usability or grade.

Deciduous

Trees which usually drop all of their leaves more or less at one time, usually in the fall.

Mill Deck

Platform where logs are held in the sawmill prior to sawing.

Log Defect

Any irregularity or imperfection in a log which reduces the volume of sound wood or lowers the durability, strength or utility value.

Dendrology

Identification or systematic classification of trees.

Crown Density

The compactness of foliage of the crowns of trees and shrubs.

Dioecious

Male and female flowers produced on separate plants.

Dominant

Trees whose crowns extend above the average level of the forest canopy.  They receive direct sunlight from above and some from the sides.

Duff

Organic debris in various stages of decomposition on top of the mineral soil.

Ecology

The study of the interrelationships between living organisms and the environment.

Even-Aged Management

Applied to a stand where relatively small age differences exist between individual trees.  The maximum age difference is usually 10 to 20 years.

Tree Farm

Area usually privately owned which is dedicated to the production of timber products.

Surface Fire

A fire which burns over the forest floor and burns only the surface litter, loose debris and small vegetation.

Exploitation

Use of natural resources with economic greed as the primary motivation and the manipulation of the environment with no consideration for sustained yield.

Firebreak

A barrier existing or constructed before a fire to serve as a line from which work can be facilitated.  Inflammable materials have been removed from the area and it is designed to stop creeping or running fires.

Multiple Use of the Forest

Management of the forest with concern for all natural resources including timber, wildlife, recreation, mining, watershed, and range. All of the uses are used without the harming or detrimental affects on the other uses.

Gall

A pronounced localized swelling of modified structure which occurs on plants usually as the result of the irritation or stimulus by another organism.

Girdle

To completely encircle the bole of a tree with cuts that completely sever the cambium layer eventually killing the tree.

Ground Fire

A fire which burns in the organic matter and down into the soil and roots.

Habitat

The site or area in which the plants or animals live.  The unit area of the environment synonymous with site.

Hardwood

Wood produced by broadleaf trees; same as porous wood.

Heartwood

The inner core of the woody stem or bole wholly composed of nonliving cells and usually has a darker color.

Hectare

A unit of land measure within the metric system.  About 2.471 acres.

Heeling  In

Placing small bundles of bare-root seedlings in a shallow trench or hole and covering the roots.

Herbicide

A chemical used for killing or controlling the growth of plants.

Humus

Plant and animal residues of the duff which is in varying stages of decomposition.

Hypsometer

Instrument used to measure tree height using geometric or trigonometric principles.

Intermediate Cuts

Harvest of trees made before a final harvest.

Intolerance

Inability of a tree to develop and grow in shade or in competition with other trees.

Kerf

Saw width of cut made by the saw.  Basically sawdust residue.

Litter

Organic materials on upper layer of the duff.

Log

a)  To cut and deliver logs aka logging.

Log(s)

b)  Tree segments, cut to length and suitable for lumber.

Lookout

A station used for detection of fires.  Usually a tower at a high point so a good view of the forest is available.

Lop

To cut limbs from trees, whether standing, felled, or fallen.

Maturity

Age beyond which growth declines in a given species.

Mensuration

Science of measurement of volume and growth and development of individual trees and stands and of the products they produce.

Merchantable Log

Size of a log, usually 16 ft., which is marketable.

Mixed Stand

Less than 75% of the stems in the stand are of the same species.

Monoecious

Having male and female flowers on the same plant.

Overrun

Excess amount of lumber actually sawed from the logs compared to the estimated volume from scaling.

Overstory

Upper crown cover

Pathology

Study of the science of diseases of forest trees or stands, and the deterioration of the products by the organisms.

Phloem

Inner bark, just outward of the cambium, that translocates food made in the leaves down to the branches, twigs and roots.

Photosynthesis

Process by which plants manufacture food and oxygen.

Pole (size class)

Name for trees less than 12 inch dbh.  Young: dbh of 4 inches.  Small: 4 to 8 inch dbh.  Large: 8 to 12 inch dbh.

Large

8-12 in dbh

Pruning

The removal of live or dead stems from dead or living trees.

Pulpwood

Wood cut or prepared primarily to be used in wood pulp manufacture for paper products, etc.

Reforestation

The natural or artificial restocking of an area with forest trees.

Rot

Wood in a state of decay.

Rotation

The period of years required to establish and grow a timber crop to a specified condition of maturity.

Sapling (size class)

A tree usually 3-10 ft. in height with a 2-4 inch dbh.  Not over 4 inch dbh.

Sapwood

The light colored wood which conducts water and nutrients to the crown of the tree.

Saw Timber

Trees that yield logs of suitable size and quality to be made into lumber.

Scale

Measuring to determine the sound volume or contents of a log or group of logs.

Seasoning

The process of reducing the moisture content of wood or lumber by exposing it to air or using a kiln.

Section

An area of land one mile square containing 640 acres.

Seeding

Planting of seed by man or by natural process.

Seedling (size class)

A tree usually grown by natural process from seed that is less than three ft. tall and smaller than a sapling.

Seed Tree

A mature tree left for natural seed regeneration or for seed collection.

Shake

A lengthwise separation of the wood usually between the annual growth rings.

Shelterwood

The establishment of natural reproduction with a partial shade left to protect the young seedlings.  Removal of the mature timber in a series of cuttings, cuts not more than 25% or less than 1/10th of the stand.

Shrub

A woody perennial with a multiple branching stem.

Silviculture

The growing or the art and science of tending the forest.

Site

An area considered as to its environmental or ecological factors.

Site Index

A species-specific measure of actual or potential forest productivity expressed in terms of the average height of trees at a specified index or base age.