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- our eNewsletter
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spacer image Maine's Changing Forests
Woodlands Glossary
The forest is a complex world with its own language. When it comes to talking about trees, many words that sound familiar mean something different. We at the Maine Forest Service believe that to Be Woods Wise, it helps to speak the language. This glossary is designed to make it easier to communicate with Foresters, loggers and others you may work with to manage your land.

A | B | C | D | E | F | G | H |I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

acre - a unit of land equal to 43, 560 square feet; a square parcel of land approximately 208.5 feet on each side.

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

all-aged stand - see uneven-aged stand.

annual rings - see growth rings.

aspect - the compass direction toward which a slope faces.


basal area - the cross-sectional area of the trunk 4 1/2 feet above the ground; most commonly used as an indicator of stand density and expressed as square feet per acre. A tree with a 14" diameter has a basal area of just over one square foot.

basal area factor 10 (20) prism - an instrument used by Foresters to determine the stocking of the forest.

best management practices (BMPs) - voluntary guidelines developed by the Maine Forest Service and Land Use Regulation Commission (LURC), determined to be the most effective and practicable means of minimizing erosion and sedimentation of water bodies (streams, ponds, lakes, rivers, etc.) from logging activities.

biltmore stick - a tool calibrated to measure the diameter of a tree at breast height.

biological diversity or biodiversity - the variety of life in all its forms and all its levels of organization. Biodiversity refers to diversity of genetics, species, ecosystems, and landscapes.

biomass - the lowest value forest product. Usually consists of stems, branches, bark, etc., that cannot be marketed in any other way. Chipped and used as fuel.

blaze - to remove a spot of bark from a tree, usually with an axe, to make a semi-permanent mark. Commonly painted to indicate boundary lines.

blowdown - any area on which (many of) the trees have been thrown or broken by the wind. See windthrow.

board foot - a unit for measuring wood volume in a tree, log, or board. A board foot is 1 foot by 1 foot by 1 inch, but any shape containing 144 cubic inches of wood equals one board foot. Usually used for sawlog material only. A common symbol is MBF, which designates one thousand board feet.

bole - the trunk or main stem of a tree.

breast height - 4-1/2 feet above ground level. See diameter at breast height.

browse - twigs, shoots, and leaves of woody plants used as food by woodland mammals such as deer, moose and snowshoe hare.

buck - to saw a felled tree into shorter lengths. A skilled logger knows the markets and can increase the value of the tree by bucking it to fit the available markets.

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. Vegetation left along a stream, lake or wetland to protect aquatic life and water quality. Buffer strips filter sediment, provide food, maintain cool water temperatures, and may increase diversity within a landscape.

bumper tree - trees near skid trails used as pivot points to turn a load of logs, usually resulting in severe injury to the bumper trees. In skid trail layout, bumper trees are left in place to protect high quality trees from skidding damage.

butt log - a log cut from the bole immediately above the stump.


canopy - the more or less continuous cover formed by tree crowns in a forest.

chopper - see logger.

clearcut - a forest harvesting practice in most or all trees are removed from a site. Clearcuts are used for immediate commercial purposes and for regeneration of future forests. Clearcuts in Maine are defined by State Statute.

codominant tree - a tree that extends its crown into the canopy and receives direct sunlight from above but limited sunlight from the sides. One or more sides of a codominant tree are crowded by the crowns of dominant trees.

commercial clearcut - a harvest cut that removes all merchantable timber from the area. See highgrading.

commercial thinning - harvests which are aimed primarily at controlling the growth of stands through adjustment in stand density. Trees removed are useful and of value for some purpose. Income from the sale or use of products produced exceeds ALL costs associated with harvesting and removing timber.

community - a collection of living organisms thriving in an organized system through which water, energy, and nutrients cycle.

competition - the struggle between trees to obtain sunlight, nutrients, water, and growing space.

conifer - commonly called softwoods or evergreens. Although there are exceptions, most coniferous trees have cones and keep their needles through the winter.

conservation easement - a legal agreement between a property owner and a qualified conservation organization or agency that restricts the uses which may be made of the property. Most conservation easements limit or prohibit development of the land for commercial, industrial, and residential uses in perpetuity.

consulting Forester - an independent professional who provides services to private woodland owners. Services may include expert advice, preparation of Forest Management Plans, appraisal of timber value, and planning and oversight of timber harvesting. Consulting Foresters do not have direct connections with firms that buy wood products, but are retained by woodland owners as their agents. See Forester.

contract - a formal, written, legally binding form of communication (agreement). In forestry, a contract is recommended between a landowner and a logger before harvesting timber, and between a landowner and a Forester for any work expected to exceed several hundred dollars.

cord - a unit of volume used in measuring wood products. A standard cord occupies 128 cubic feet of space and contains approximately 85 cubic feet of wood. It is commonly described as a close piled stack of wood 4 feet high, 8 feet long, with sticks 4 feet in length. A cord is the legal measure of fuelwood volume in Maine.

cordwood - small diameter or low quality wood suitable for firewood, pulp, or chips. Cordwood is not suitable for sawlogs.

cost share assistance - an assistance program offered by various state and federal agencies that pays a fixed rate or percentage of the total cost necessary to implement a forestry practice.

crook - a tree defect characterized by a sharp bend in the main stem.

crop tree - those trees in a stand destined to form the final crop, usually the highest quality and value of all the trees in a stand. Crop trees may be selected from an immature stand and carried through to the final harvest.

crotch - see fork.

crown - the live branches, twigs, and foliage of a tree.

crown classes - a classification of the position of an individual tree's crown relative to the rest of the forest canopy. See codominant, dominant, intermediate, overtopped, and suppressed.

crown closure - the percentage of a given area covered by tree crowns.

crown ratio or live-crown ratio - the ratio of the length of live crown of a tree to its total height. Live crown ratio is usually expressed as a percentage of total height.

cruise - a systematic, statistically valid forest inventory used to obtain qualitative information about the forest. A cruise is often the first step in developing a Forest Management Plan; the estimate obtained in such a survey.

cull - trees or logs which are rejected, or volumes deducted in log scaling because of a defect.

cutting cycle - the period of time between major harvests in a stand, usually determined by the type of management being practiced, the condition and type of the forest, and the growing conditions of the soil.


deciduous - shedding or losing leaves annually. Trees such as maple, ash, cherry, and larch are deciduous.

deed - a legal document used to transfer title in real property from one person to another.

defects - any irregularity or imperfection on a tree, log, or other wood product that reduces the volume of usable wood or lowers its durability, strength, or utility value. Defects may result from knots and other growth conditions and abnormalities; from insect or fungus attack; or from logging, or other processing procedures.

den tree - a tree with holes or cavities suitable for birds or mammals to nest in.

diameter at breast height (dbh) - standard measurement of a tree's average diameter, outside the bark, taken at 4 1/2 feet above the ground.

diameter-limit scale - a timber sale in which all trees over a specified diameter may be cut. Most Maine forests are even-aged and small diameter trees are as old, although not as vigorous as the larger stems. Diameter-limit sales often result in highgrading. This type of cutting is not usually regarded as wise, long-term forest management as it can cause the loss of stand vigor from the removal of the fastest growing trees.

dimension lumber - wood products that are sawn from logs. Hardwood dimension lumber is often used in the manufacture of furniture or other products. Softwood dimension lumber is most commonly used in construction, furniture, and other products.

disturbance - a change in forest cover cause by natural or human causes. Common forest disturbances in New England include clearing for agriculture, abandonment of agricultural fields, windstorms, ice storms, fire, flood, logging, mining, and development.

dominant - trees whose crowns extend above those of surrounding trees which capture sunlight from above and on one or more side of the crown.

duff - forest litter of organic debris (in various stages of decomposition) on top of the mineral soil.


easement - see conservation easement.

ecology - the study of interactions between organisms and their environment.

ecosystem - organisms and the physical, chemical, and biological factors that make up their environment.

edge - the boundary between two ecological communities, for example, field and woodland. Edges often provide habitat for certain wildlife species.

endangered or threatened species - 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. A threatened species exhibits declining or dangerously low populations but still has enough members to maintain or increase numbers.

epicormic branching - branches that grow out of the main stem of a hardwood tree from dormant buds produced under the bark, usually in response to damage or an increase in light. Severe epicormic branching increases knottiness and reduces lumber quality.

even-aged stand - a stand in which most trees originated around the same time (i.e. the age difference between the oldest and youngest trees is minimal, usually no greater than 10 to 20 years. ) Even-aged stands result from cutting of all the trees in a stand within a relatively short period of time, major natural disturbances (such as fire), or reversion of cleared land to forest.

even-aged management - managing a forest or forest stand to produce a forest of trees of the same relative age. Even-aged management techniques include intermediate treatments, clearcuts, patch clearcuts, and shelterwood cuts.


felling - the cutting of standing trees.

filter strip - an area of forest adjacent to a water body where measures are taken to limit disturbance of the forest floor (natural vegetation, soil, and forest litter, or fallen leaves and branches) to prevent erosion during or after timber harvesting.

flagging - the act of temporarily designating the location of a road, trail, or boundary by hanging strips of colored plastic on trees or stakes.

forest - a biological community dominated by trees and other woody plants.

forest fragmentation - the division of large natural landscapes into smaller, more isolated fragments, due to development, road construction, or other changes. Fragmentation affects the viability of wildlife populations and ecosystems, and may reduce options for forest management by reducing woodlot size.

forest management - the application of sound forestry principles and practices to the operation of the woodlands.

forest management plan - a written document, based on landowner objectives and resources on the ground, which guides future activities to care for the land and accomplish the landowner's objectives over the long term. Plans may consider many resources including wildlife, recreational opportunities, aesthetics, timber, water, soil, wetlands, unique features, and cultural resources.

forest types - associations of tree species that have similar ecological requirements. Some common forest types in Maine are spruce-fir, northern hardwoods, pine-oak, and poplar birch. Often types are simplified into hardwood, softwood, and mixed wood.

forested wetland - an area dominated by woody vegetation taller than 20 feet where soil is at least periodically saturated or covered by water. forester - a professional, usually with a college or university degree, trained in forestry and forest management. In Maine, all Foresters must be licensed by the state.

forestry - the art, science, and craft of tending woodlands to derive benefits to humans.

fork - a tree defect characterized by the division of a bole or main stem into two or more stems. See also crotch.

form - with reference to a tree, the degree of taper between diameter at the tip of a 1 foot stump and diameter at the top of the first 16 foot log.


girdle/ girdling - the removal or killing of a ring of bark around the tree stem so that the flow of carbohydrates from crown to roots is blocked. The roots die and the whole tree is killed. Usually used to create a snag for wildlife habitat or to eliminate the influence of a large tree's presence in the canopy without actually felling the tree.

grade - the rise or fall in ground level over 100 feet of horizontal distance, expressed as a percentage.

grade log - the designation of the quality of a manufactured piece of wood or of logs.

great pond - any natural inland body of water with surface area over 10 acres, or artificially created or increased body of water over 30 acres.

group selection - a method of regenerating uneven-aged stands of trees by removing/harvesting trees in small groups or patches (usually less than acre). Group selection typically encourages the reproduction of tree species that are somewhat to moderately tolerant of shade.

growing stock - trees capable of producing at least one 12 foot sawlog now or in the future.

growth rings - the layers of wood a tree adds each growing season. These rings frequently are visible when a tree is cut and can be used to estimate its age and growth rate. See also annual rings.


habitat - the ecosystem in which a plant or animal lives and depends on for cover, breeding sites, food, and water.

hardwoods - a general term encompassing broadleaf, deciduous trees.

hardwood type - a forest in which hardwood tree species comprise at least 75% of the stand.

harvest - the cutting, felling, and removal of forest timber or other forest materials.

herbaceous vegetation - low-growing, non-woody plants, including wildflowers and ferns, in a forest understory.

high grading - an exploitive logging practice that removes only the best, most accessible, and valuable trees from a stand, leaving lower quality trees to grow into a lower quality forest. High grading should be distinguished from even-aged management in which mature and immature trees are removed to aid regeneration.


improvement cut - an intermediate treatment to improve the growth rate and vigor of residual trees. An intermediate cut made to improve the form, quality, health, or wildlife potential of the residual stand.

increment borer - an auger-like tool with a hollow bit designed to extract cores from tree stems for the determination of age and growth rate.

intermediate tree - trees with crowns that extend into the canopy with dominant and codominant trees. These trees receive little direct sunlight from above and none from the sides. Crowns generally are small and crowded on all sides.

intolerance - see tolerance

introduced species - a nonnative species that was intentionally or unintentionally brought into an area by humans.


jobber - see logger.

No glossary entries.

landing - a cleared area within or adjacent to a timber harvest where logs or tree length material are processed, piled, stored and loaded for transport to a sawmill or other facility. See also yard.

landowner objectives - goals that landowners have for the current and future use of their property. They are deliberately thought out and defined in order to formulate a course of action to accomplish them.

liquidation harvesting - the purchase of timberland, followed by the removal of most or all commercial value in standing timber and prompt resale of the land. This is generally viewed as inconsistent with accepted principles of forest stewardship. It is often a speculative practice that leads to hasty land subdivision.

log - a section of the main stem of a tree, varying in length and minimum diameters according to local market standards, that is usually sawn into lumber. As a verb, log refers to the process of harvesting, extracting, and transporting logs to a mill.

log grading - the assignment of a quality class to a log.

logger - an individual who harvests timber for a living.

log rule or scale - a method for calculating wood volume in a tree or log by using its diameter and length. The international 1/4-inch rule is the legal rule in Maine

log scaling - the estimation of the board foot volume to be sawn from a log. A log scale volume is an accepted form of measurement in log marketing.

lopping - cutting tree tops and branches from felled trees, to bring them closer to the ground. Lopping can increase visibility, improve the forest's appearance, reduce fire danger, and speed up the rotting and return of nutrients to the soil after harvesting.

lump-sum sale - a timber sale in which a total price for all standing trees to be harvested is contracted, based on their estimated total value. The lump sum is set before the wood is removed and typically paid in a single payment (See also unit sale).


marking - the practice of indicating by paint or other visible, semi-permanent means trees which are to be cut or are to remain after harvesting. A common practice is mark trees to be harvested twice-once at eye level and once at the base. Marking may also be used to designate trees for other treatments, such as pruning.

mast - fruits, nuts and seeds, of trees and shrubs that serve as food for wildlife. "Hard mast" refers to nuts such as acorns, beechnuts, or hazelnuts. "Soft mast" refers to fruits such as cherries, wild apples, and various berries.

merchantable height - the point on a tree stem to which the stem is salable.

mixed wood type - forest stands occupied by a mixture of softwood and hardwood tree species. Neither hardwood nor softwood tree species occupy more than 75% of the tree stocking.


natural regeneration - seedlings from natural seeding or sprouts and other plants representing vegetative reproduction.

niche - the physical location and functional role of an organism within an ecosystem and how it interacts with other species.

nongame wildlife - wildlife species that are typically not hunted, either by common practice or by state wildlife laws. Examples include songbirds, eagles, amphibians, insects, etc.

nonindustrial private forestland (NIPF) - woodland owned by a private individual, group, or corporation not involved in wood processing. Fifty-five percent of Maine's forests are in this category.


objectives - see landowner objectives.

old-growth forest - a wooded area that has no evidence of harvest or alteration by humans. An old-growth forest often has large individual trees, a multi-layered crown canopy, and a significant accumulation of large woody material, including snags and fallen logs.

overmature - a quality exhibited by trees that have declined in growth rate because of old age and loss of vigor.

overstocked - the situation in which trees are so closely spaced that they compete for resources and do not reach full growth potential.

overstory - the level of forest canopy that includes the crowns of dominant, codominant, and intermediate trees.

overstory removal - see shelterwood.

overtopped - the situation in which a tree cannot sufficiently extend its crown into the overstory and receive direct sunlight. Overtopped trees that lack shade tolerance lose vigor and die. See suppressed.


pallet log - a low grade hardwood log suitable for producing low grade products like pallets.

patch cut - removal of all trees within designated small areas in the harvest area. Areas are larger than those cut in a group selection method harvest. An even-aged management technique.

pesticide - any chemical used to control undesirable insects, vegetation or animals, or to guard against or treat a forest health problem.

pole stand - a stand of trees whose average dbh is between 4 and 10 inches.

precommercial treatments - forestry operations that require landowner investment, such as cleaning or weeding stands to remove trees that have little or no economic or market value. Precommercial treatments can improve species composition and increase the quality, growth, and vigor of remaining trees.

prescription - a course of action recommended to bring about a desired change in a forest stand.

pruning - the act of sawing or cutting branches from a living tree. In forest management, pruning is done to promote the growth of clear wood free of knots, from which more valuable, knot-free boards can be sawn. Pruning is usually done in conjunction with a thinning.

pulp/ pulpwood - wood suitable for use in paper manufacturing.


No glossary entries.

reforestation - the establishment of a forest through artificially planted seed or seedlings. The vast majority of forests in Maine regenerate naturally without need for planting.

regeneration - the process by which a forest is reseeded and renewed. Advance regeneration refers to regeneration that is established before the existing forest stand is removed.

release - the process by which young stands of desirable trees, not past the sapling stage, are freed from the competition of undesirable trees that threaten to suppress them.

residual stand - the trees remaining uncut (and hopefully undamaged) following any cutting operation.

riparian zone - a strip of variable width, depending on the riparian functions identified, where special management considerations may be advisable to maintain or enhance those functions. Riparian functions can include protecting bank and channel stability, maintaining shade and inputs of vegetation to the water, carrying water to the surface, maintaining water quality, and providing wildlife habitat.

roadside sale - a timber harvest in which trees are harvested, brought to a place accessible to a log truck, and are sold from that location.

rot - a tree defect characterized by woody decay in a standing tree or log.

rotation - the number of years required to grow a stand to a desired size or maturity. See even-aged management.


salvage cut - the removal of dead, damaged, or diseased trees to recover maximum value prior to deterioration.

sanitation cut - removal of diseased, damaged, overmature, or undesirable stems from a stand.

sapling - a tree from 1 to 4 inches in diameter.

sapling stand - a stand of trees whose average dbh is between 1 and 4 inches.

sawlog - a log of sufficient size and quality to be sawed economically on a sawmill for use in lumber and other products.

sawlog tree - a standing tree that contains at least 1 sawlog.

sawtimber - sawlog sized trees.

sawtimber stand - a stand of trees where sawlog trees predominate.

scale stick - a calibrated stick used to estimate wood volume in a log.

scaling - the process of measuring the dimensions of individual logs or trees. The measurements are used to estimate the volume of the logs or trees by applying them to a log rule or tree volume table.

scarification - the disturbance of the forest floor to expose areas of mineral soil. This is done to prepare a seedbed and encourage establishment of desired species of tree seedlings.

sealed-bid sale - a lump sum or unit timber sale, usually offered with the assistance of a consulting Forester, in which buyers submit secret bids.

seed tree - a mature tree left uncut to provide seed for regeneration of a harvested stand.

seed-tree harvest - the felling of all the trees in an area except for a few desirable individuals that provide seed for the next forest. An even-aged management technique.

seedling - trees that are less than 3 feet tall.

selection harvest - a method of harvesting in which individual trees or small groups of trees are removed to regenerate new seedlings andmaintain an uneven-aged forest. Selection harvests are used to manage species that do not need high levels of sunlight to regenerate and survive in the understory.

selective harvesting - often used as a "catch all" for all types of partial cuttings. It is an exploitive cutting and often used to describe highgrading, liquidation harvests, and diameter limit cutting. Who is doing the selecting and what criteria are they using?

shelterwood harvest - a method of regenerating new, even aged stands by harvesting all mature trees in an area in a series of two or more cuts occurring within 10-20 years. One or more cuts leaves merchantable trees to provide shade and protection for the establishment of forest seedlings. The second or third cut, or final removal, removes the remaining mature trees to give the regenerated trees full sunlight.

silviculture - the art and science of growing and tending forest trees.

single-tree selection - removal of single trees distributed throughout a harvest area.

site - the combination of biotic, climatic, topographic, and soil conditions of an area that determines the character and productivity of forest stands.

site index - a measure of the quality and potential productivity of a site based on the height of dominant trees at a specified age (usually 50 years), depending on the species.

site preparation - treatment of the forest floor and/or understory vegetation of an area to facilitate natural or artificial reestablishment of a forest stand. Site preparation can include mechanical clearing, burning, or chemical (herbicide) vegetation control.

skid - to drag logs or tree lengths either wholly or partially on the ground.

skidder - a generic term for a machine (usually rubber-tired) with a cable winch or grapple used to drag logs out of the forest.

skidding - the act of moving trees from the site of felling to a leading area or landing. Tractors, horses, or specialized logging equipment can be used for skidding. Skidding methods and operator skill vary significantly, and as a result differ in their efficiency and impact on soils and the remaining stands.

skid road / skid trail - an unsurfaced single-lane road used by skidders and other extraction equipment to access forest products for transport from the harvest area to the yard or landing.

slash - bark, branches, uprooted stumps and other woody material left on a site after logging, road construction or land maintenance. As a verb, to cut sawlogs to merchantable length from whole trees.

snag - dead standing trees, often with tops broken off. Snags serve as perches, lookouts, and provide important food and cover for a wide variety of wildlife species.

softwood - used to designate all coniferous (cone bearing species) as a class, including pines, hemlock, larch or hackmatack, spruces, balsam fir, and cedar.

softwood type - a forest in which softwood tree species comprise at least 75% of the stocking.

springpole - saplings or smaller trees that are bent over by a larger felled tree. They can be under extreme tension and are dangerous.

sprout - a tree growing from a cut stump or previously established root system. See also sucker.

stand - a group of forest trees of sufficiently uniform species composition, age, and condition to be considered a homogeneous unit for management purposes. See also forest types.

stand density - the quantity of trees per unit area, usually evaluated in terms of basal area, crown cover and stocking.

stewardship - the act of taking care of your land for the long term. Leaving your property in better condition than you found it.

stewardship plan - see Forest Management Plan.

stocking - a measurement of how fully the trees in a forest stand occupy the available growing space of the site, expressed in terms of trees per acre, basal area per acre, volume per acre, or percent crown closure. Stands are often classified as understocked, well-stocked or overstocked.

stratification - the tendency of competing trees and shrubs in a developing stand to separate into different layers. The stratification of a stand can provide distinct niches for wildlife. See canopy, understory, and herbaceous vegetation.

stream channel - A channel between defined banks created by the action of surface water and characterized by the lack of terrestrial vegetation or the presence of a bed, devoid of topsoil, containing waterborne deposits or exposed soil parent material or bedrock.

streamside management zone - a forested area beside a stream or other body of water which is managed to protect or enhance the values associated with the water body, such as water quality, aquatic and other wildlife habitat.

stem - see bole.

stumpage - the value of standing trees in a forest.

stumpage price - the price offered or paid for standing forest trees.

stumpage sale - a timber sale arrangement where a fee is paid to the landowner for the standing trees, accompanied by the right of the buyer to harvest the trees from the property under agreed conditions.

stump height - the distance from the ground to the top of the stump. Good logging practice dictates that stumps be as low as possible (preferably as low as 12 inches) to reduce waste and to minimize visual impact on the logging site.

succession - the natural replacement of one plant (or animal) community by another over time in the absence of disturbance.

suppressed - a tree condition characterized by low growth rate and low vigor as a result of competition with overtopping trees. See overtopped.

sustainability - the ability of the natural environment to supply goods and services to humans for the indefinite future.

sustained yield - an idealized forest management objective in which the volume of wood removed equals growth within the total forest over an appropriate period of time.

sweep - a tree defect characterized by a gradual curve in the main stem.


thinning - a partial cut in an immature, overstocked stand of trees used to increase the stand's value growth by concentrating on individuals with the best potential.

timber stand improvement (TSI) - any practice that increases the rate of growth or improves composition or quality in a developing stand of trees, thus enhancing its potential value. Pruning, thinning, and weeding are considered TSI.

timber trespass - the negligent curring or removal of trees on a property without landowner permission.

tolerance - a tree species' ability to grow and thrive in shade.

trim allowance / trim - the extra 4 to 6 inches left on a bucked log to allow logs with end checks, pulls, or slanting buck cuts to be trimmed to standard lumber lengths.

twitch - see skid.


understocked - a stand of trees so widely spaced that crown closure will not occur; such stands typically do not fully occupy the site nor can they achieve the site's full growth potential.

understory - the smaller vegetation (shrubs, seedlings, saplings, small trees) within a forest stand, occupying the vertical zone between the overstory and the herbaceous plants of the forest floor.

uneven-aged stand - an area of forest composed of trees of similar species, in which trees of several age classes are represented. See all aged stand.

unit sale - a timber sale in which a separate price is agreed upon for multiple species/product combination, and payments to the landowner are based on the actual measurements of wood products shown in mill receipts. Payments under a unit sale typically occur within an agreed-upon time frame for wood trucked since the last payment.


veneer log - a high-quality log of a desirable species suitable for conversion to veneer. Veneer logs must be large, straight, of minimum taper, and free from defects.

vernal pool - an ephemeral body of water that fills in the spring, holds water for at least 10 days, and dries up by fall some or all years and that does not contain fish. Vernal pools are extremely important habitat for a variety of amphibians and reptiles.

virgin forest - see old-growth forest.


water bar - a small earth berm or dam constructed at an angle across a skid road or trail to direct surface water to a stable vegetated surface or filter strip.

watershed - a region defined by patterns of stream drainage. A watershed includes all the land that contributes water to a particular point of interest on a stream, river, lake, or coastal feature.

weeding - the removal of all plants competing with a crop species, regardless of whether their crowns are above, beside, or below those of the desirable trees. Removal of diseased, damaged, and poor quality trees.

well-stocked - the situation in which a forest stand contains trees spaced widely enough to prevent competition yet closely enough to utilize the entire site.

wetlands - ponds, freshwater swamps, marshes, bogs and similar areas that are inundated or saturated by surface or groundwater at a frequency and for a duration sufficient to support, and which under normal circumstances do support, a prevalence of wetland vegetation typically adapted for life in saturated soils. Wetlands may be either freshwater or tidal.

wildlife habitat - the native environment of an animal. Habitats ideally provide all the elements needed for life and growth: food, water, cover and space.

windfirm - the ability of the root system of a tree to withstand wind pressure and keep the tree upright.

windthrow - a tree felled by wind. Windthrows, also known as blowdowns, are common among shallow-rooted species and in areas where cutting has reduced stand density.

wolf tree - a large older tree with a spreading crown and little or no timber value, but often having great value for wildlife. The same function as a snag, except the tree is still alive and possibly producing mast.

woodland - see forest.


No glossary entries.

yard - see landing.

No glossary entries.

Note: adapted from the Maine Forest Service "Women and the Woods" program and the Pennsylvania State University Cooperative Extension bulletin "Forestry Terminology".


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Maine Forest Service
Department of Conservation
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Augusta, Maine 04333-0022

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