Botantical / Plant Terms

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Barrens

Woodland or shrubland communities where tree establishment or growth is suppressed by

environmental conditions and/or disturbance regime; often found on thin or excessively drained soils.

Bog

a nutrient-poor, acidic peatland that receives water primarily from direct rainfall, with little or no input

from groundwater or runoff; vegetation consists primarily of peat mosses (Sphagnum spp.) and ericaceous

shrubs.

Canopy

branches and leaves of plants that form the uppermost layers of vegetation in a community; a canopy

is said to be closed (or have 100% cover) when the lower strata are fully shaded during the growing season.

Characteristic species:

a species strongly associated with a particular community type, either as a dominant or

very common component.

Co-dominant

a species with relatively high abundance or percent cover; two or more species providing

roughly equal cover, abundance, or influence in a community or stratum

Community

an assemblage of plants and/or animal populations sharing a common environment and

interacting with each other.

Conifer

any of a large group of cone-bearing trees and shrubs, mostly evergreens such as the pine, spruce, fir,

cedar, etc.; some conifers drop their leaves yearly and thus are not ‘evergreen’ (e.g. tamarack, bald

cypress).

Disturbance

a temporary change in average environmental conditions that causes a pronounced change in

ecosystem; may be natural (e.g. blow-down) or human-induced (e.g. logging, introduction of invasive

species, etc.)

Dominant:

a species with the greatest abundance, percent cover, or influence in a community or stratum

Edaphic

relating to soil, especially as it affects living organisms. Edaphic characteristics include such factors

as water content, acidity, aeration, and the availability of nutrients

Ericaceous

members of the heath family (Ericaceae)

Exotic:

species not native to Pennsylvania, or to the area in which they occur

Forb

a broad-leaved (not grass-like) herbaceous plant; may include ferns and fern-allies

Forest

a type of community dominated by trees greater than five meters in height, and having at least 60%

canopy closure, crowns usually interlocking; may be terrestrial or palustrine

Graminoid

grass-like, narrow leaved herbaceous plants; includes grasses (Poaceae), sedges (Cyperaceae), rushes

(Juncaceae), and a few others

Grass

a member of the grass (Poaceae) family.

Ground layer / Ground flora

the herbs, shrubs, and woody vines beneath the trees in a forest; or the lowest

layer of vegetation in an open-canopy community

Hardwood

in our region, broad-leafed deciduous trees

Heath

a member of the family Ericaceae; ericaceous plants thrive in acidic soils9