Definitions

Source: PEI Ecosystem-Based Forest Management Standards Manual (October 2025), pp. 39–48

Terms are listed alphabetically. Where the manual attaches a number to a term, that number is the standard used throughout this guide.

A

Alternate species — A tree or shrub kept during a treatment such as plantation cleaning or thinning for species diversity and nutrient cycling, rather than as a crop. At least 15% of residual density is expected to be alternate species (see Diversity Enhancement).

Appropriate natural regeneration — Naturally established seedlings of species that would be kept as crop trees in a prescription such as cleaning or thinning.

B

Basal area — The cross-sectional area of a stem at breast height, expressed per tree (m²) or summed per hectare (m²/ha).

Biodiversity — The variety of life at three levels: genetic diversity within a species, diversity of species, and diversity of ecosystems. It matters in its own right and for what it provides — clean air and water, compounds for medicines, seed for new crops. Losing species, or shifting the species mix, can harm ecosystem health and economic and cultural sustainability.

Breast height (BH) — The standard measuring height on a standing tree: 1.3 m above the ground.

Buffer zone — The 15 m strip around every watercourse and wetland on PEI.

Bull pen — A natural or cleared opening where organic soil, slash and roots from road building are placed, keeping damage to nearby trees to a minimum.

C

Cavity tree — A live or dead tree, preferably more than 20 cm DBH and more than 7 m tall, that wildlife may use for roosting or breeding — whether or not it already has cavities. See also snag.

Coarse woody debris (CWD) — Downed wood at least 7.5 cm in diameter and 2 m long, left on site as microhabitat for plants and wildlife. Harvest sites keep at least 200 pieces per hectare.

Commercial thinning — A cut in an immature or mature stand that changes species composition, speeds growth and/or raises the share of well-formed trees of the desired species and structure, for timber or non-timber goals. Merchantable trees felled are piled on the trail system, or placed where they benefit wildlife.

Contour ploughing — Mechanical site preparation using a single-furrow plough to turn over sod and make planting spots, run across the slope. The turned sod must sit firmly on the ground so planted seedlings don’t dry out.

Cover patch — An uncut area of at least 25 m² (100 m² or more is better) left inside a cleared area as wildlife cover and a reserve of natural vegetation. Ideally it has several canopy layers and contains a cavity tree, a legacy tree, or better still both. It is excluded from treatment and left to develop naturally, possibly with enrichment planting. Larger patches hold a better mix of ground cover, shrubs, trees, deadwood, fallen and leaning trees, upturned roots and dense canopy.

Crop tree — A tree selected for a future harvest.

Crown — The live-branched, leafy portion of a tree.

Crown class — A tree’s position in the canopy:

Culvert — A metal, wooden, plastic or concrete pipe or channel that carries water under a road or trail.

D

Damaged residual — A tree left standing after an operation whose main stem has cambium damage: bark damage and/or broken limbs that expose more than 10 cm² of sapwood.

Debris (around water) — Any loose material that has entered, or could enter, a watercourse or wetland. Examples: gravel, clay, rocks, stumps, branches, whole trees, lumber, or anything used to build a crossing. Fallen trees lying in the watercourse within 5 m of a crossing structure also count.

Density — Number of trees per hectare.

Diameter at breast height (DBH) — Stem diameter measured 1.3 m above the ground.

Duff — The organic layer on the forest floor: litter (freshly fallen leaves, twigs and bark, only slightly decomposed) over less-decomposed humus.

E

Early successional species — Trees and shrubs that thrive in full, open light and are largely shade-intolerant, such as pin cherry, white birch and eastern larch.

Ecosystem — Living organisms and their environment, interacting as a self-sustaining whole.

Extraction trail — A narrow lane for hauling harvested wood or other products out to a forest road. It is normally as wide as the extraction machine (forwarder, skidder, tractor and trailer), plus enough extra for rough terrain to avoid damaging residual stems.

F

Forest — Land where trees cover, or will cover, at least 10% of the area.

Forest ecosystem — An ecosystem (plants, animals, microorganisms and their physical setting) where trees dominate.

Forest management — Managing forest resources for multiple uses and sustained yields of wood, water, wildlife and recreation. It spans timber, watershed, wildlife and fisheries, and recreation management.

Forest stand — A group of trees uniform enough in species, height, density, age and structure to be managed as one distinct unit.

Forested wetland — Forest with a high water table (at or close to the surface), saturated soil or standing water, where woody plants cover at least 30% of the ground. Examples include shrub swamps, treed swamps, fens and bogs. These are biodiversity hotspots on PEI and should be prioritized for conservation.

Full planting — Planting an area to 1,400–2,500 seedlings per hectare. The Full Planting treatment sets its own ranges by species group.

G

Girdling — Removing a ring of bark and cambium around a tree to kill it, often to create a wildlife tree.

H

Habitat — The place and conditions in which an organism normally lives.

Hardwood stand — A stand where more than half of the overstory trees are hardwoods.

Hardwood trees — Broadleaved trees that drop their leaves every year.

I

Immature — See maturity class.

Invasive species — A non-native species that spreads aggressively into habitats, often treated as a weed or pest. See Invasive Species.

L

Late successional species — Shade-tolerant hardwoods, softwoods or shrubs that can thrive under a canopy — for example beech, sugar maple, red maple, eastern hemlock, white pine and ground hemlock.

Legacy tree — A standing live tree that stands out for its size (height and/or diameter), great age, rarity or historical significance.

Live crown ratio — How much of a tree’s total height carries green branches, as a percentage.

M

Management plan or agreement — A document that describes an area of land, sets its management objectives, and lists the treatments to reach them. It may include or refer to this manual, or another document setting minimum standards for the work (see Woodlot Management Plan).

Maturity class — A grouping of trees or stands by how ready they are to yield a given product, most often timber:

Merchantable trees — Normally, all live standing trees 9 cm DBH or larger.

Merchantable wood — Merchantable trees, or parts of trees, felled for a specific use.

N

Native species — A species that occurs naturally in a region and was not introduced by people during the region’s written history.

Natural regeneration — Vegetation renewing itself without planting — from seed, sprouts, suckers or layering.

Nest tree — A live or partly dead mature aspen, beech, maple or birch at least 20 cm DBH, valued for its potential to develop nest cavities.

Non-timber forest products — Any product or value from the forest other than primarily roundwood (pulp, studwood, logs and fuelwood).

P

Partial herbicide application — A ground herbicide application in which only part of the site is treated, usually by band or spot spraying.

Partial planting — Planting seedlings intermittently across an area at 200–1,000 per hectare.

Patch cutting — Cutting openings in woody vegetation to regenerate trees, shrubs or other plants, to start a new maturity class, or to create the shade and microclimate that planted stock needs to survive and grow well. Openings are normally 0.3–2 times the stand height across (see Patch Harvest).

Plantation — Land whose main woody vegetation was established by planting or seeding trees or shrubs (or their cuttings) to a prescribed density, and which is managed mainly to produce one or more crops.

Pre-commercial thinning — A cut in a young stand that reduces competition to favour particular species and/or speed crop-tree growth. The trees cut are usually not merchantable.

Pruning — Cutting tree limbs to shape the stem for a particular use, or to reduce disease or insect infestation in crop trees.

R

Regenerating — See maturity class.

Regeneration cutting — Felling individual trees or groups mainly to promote desirable regeneration, create a new maturity class, or create shade and microclimate conditions for planted stock.

Replanting — Establishing a plantation by planting seedlings or transplants on land that was previously forest or plantation.

Riparian management zone — An operable management area along a watercourse, large enough to be practical for contractors: the full length of the watercourse plus a 50 m strip on each side. The wetland management zone is the 50 m strip around a wetland’s perimeter (see Riparian Management Zone).

S

Scarification — Manual or mechanical preparation of a seedbed or planting spot. It exposes mineral soil or thins the humus layer to help particular species germinate and grow, or temporarily reduces plant or animal competition.

Seed bed — An area whose soil has been modified enough for the desired species to establish from seed.

Shrub — A woody plant that usually grows several equally strong stems and stays under about 4.6 m (15 ft).

Site index — A measure of how productive a site is: the height, in metres, a given species reaches at breast-height age 50.

Site preparation — Treating a future planting site by hand, by machine or with herbicide: removing or controlling unwanted vegetation or slash and/or breaking up and mixing soil layers, before planting or to favour chosen species.

Skidder — A machine that moves harvested wood from the stump to roadside using cables or grapples.

Snag — A standing dead or leaning tree, preferably more than 20 cm DBH.

Softwood — Cone-bearing trees with needles or scale-like leaves.

Softwood stand — A fairly uniform group of trees, managed as one unit, in which more than half of the overstory trees are softwoods.

Species diversity — Species richness in an area, broken down by an attribute such as native versus non-native.

Species richness — The number of species in a given area.

Stem — For stand density counts, any tree taller than 1.3 m.

Stocking — A qualitative measure of how well an area is covered by trees, compared against a pre-set norm.

Strip cut — Felling in strips to promote desirable regeneration and/or wildlife habitat, create a different maturity class, or create shade and microclimate for planted stock. Strip width and compass orientation control how much shade results (see Strip Harvest).

T

Thinning — A cut that changes a stand’s species, speeds the diameter growth of the remaining trees, and improves their average form for a given purpose.

Trail percentage — The share of a stand’s area occupied by extraction trails. Trail width includes both travelled and untravelled surface, measured as the average distance between residual stems.

Tree — A woody plant that usually has a single main stem and generally grows taller than 6 m (20 ft).

Tree regeneration — New trees from seed, root suckers, stump sprouts or layering:

• Hardwoods: most cut below their lowest live branch will resprout — from the roots (e.g. trembling aspen) or the stump (e.g. sugar maple, white birch).
• Softwoods: most die when cut below the lowest green branch.
• Layering: a few species regrow from branches buried by events such as blowdown, e.g. eastern white cedar.

U

Unploughed forest — Treed land that was never cultivated for crops or pasture.

V

Value-added product — A product made from a base commodity — for example, fresh fruit turned into jam, jelly, syrup or dried berries.

Vernal pool — A temporary pond in a forest hollow that dries out during the year. Longer-lasting pools are important breeding habitat for salamanders, newts, frogs and toads.

W

Watercourse — Any stream, brook, creek, spring, river, pond, lake, bay, estuary or coastal water body: its whole bed, banks and shore, along its full length and width, wet or dry. Grassed waterways and tap drains don’t count, except a tap drain that a watercourse has been diverted into. For riparian zones specifically, a watercourse has a defined bed and banks connecting to a larger watercourse, or flows continuously for any 72-hour period between July 1 and October 31 in any year.

Watershed — The area of land draining, over the surface or through the ground, to a particular river or stream. All of PEI divides into watersheds; the Winter River basin northeast of Charlottetown is one example.

Wet forest — Forest with water at or near the surface, but not wet enough to support wetland vegetation. Often a black spruce stand with true wetlands inside it.

Wetland — Marshes (including salt marshes), swamps, bogs, flats and shallow-water areas: land saturated long enough for wetland or aquatic processes to develop. Signs include poorly drained soil, water-tolerant vegetation and biological activity adapted to wet conditions.

Wildlife — Non-domesticated living things, including plants, spiders, birds, reptiles, fish, amphibians and mammals.

Wildlife tree — Any tree selected to remain in a stand for the benefit of wildlife.

Based on the PEI Ecosystem-Based Forest Management Standards Manual (October 2025), pp. 39–48. Where this guide and the manual differ, the manual governs.