Glossary Term: definition

Biogeoclimatic subzones

Biogeoclimatic subzones are the basic unit of climatic classification in British Columbia. Each subzone comprises a geographic area with a fairly uniform regional climate and a typical pattern of vegetation and soils. Subzones are grouped into biogeoclimatic zones to create more generalized units, and these are named after the climatic region and climatic climax plant community.

Biotic community

A biotic community is a group of organisms that live together and interact with each other within an environment or habitat. Together, the biotic community and the physical landscape (abiotic factors) make up an ecosystem.


Bryophytes are non-vascular seedless land plants (mosses, liverworts, and hornworts). Although they exhibit specialized structures for water transportation, they have no vascular tissue or true roots.

Carbon Sink

Forests absorb carbon dioxide from the air through photosynthesis and the carbon is stored in trees and other components of the ecosystem. Forests also produce carbon dioxide through respiration, decay or when they burn. A forest is a carbon sink if it absorbs more carbon than it produces. Conversely, if a forest produces more carbon than it absorbs it is a carbon source.

Chronosequence study

A chronosequence study in forest sciences is a study that takes place on a set of forested sites that share similar attributes (e.g., climate and topography) but are of different ages


Cryptogams are plants that have no true flowers or seeds and reproduce by spores. They include mosses, liverworts, and lichens. Ferns are considered advanced cryptogams because they reproduce by spores but are differentiated into roots, stems and leaves.

Read more about cryptograms.


CWHvm is the abbreviation for the very wet maritime Coastal Western Hemlock biogeoclimatic subzone. The province of British Columbia is divided into 16 zones, including the Coastal Western Hemlock (CWH). A zone is a large geographic area with a relatively uniform regional climate. The CWH zone is subdivided into climatically distinct subzones, including the vm, or very wet maritime subzone. The CWHvm has a wet, humid, mild, oceanic climate and has an extensive distribution on the BC coast including western Vancouver Island.


Epiphytes are plants, including lichens, which rely on other plants for support, growing on trunks and branches rather than rooting themselves to the ground. They are not parasitic on the supporting plants but rather derive nutrients from the air and small pools of water that collect on the host. Epiphytes are also referred to as epiphytic plants.


Evapotranspiration is the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces as well as by transpiration from plants.


Gametes are reproductive cells in sexually reproducing organisms that fuse with one another during fertilization. The male and female gametes each contain half the genetic material necessary to form a complete organism.