What Is Vegetation?
The term vegetation is used in ecology to describe the overall characteristics of plant cover in an area by:
- referring to dominant plant growth forms or structural characteristics, e.g., forest vegetation, grassland vegetation;
- using either colloquial or technical descriptors, e.g., desert vegetation, cliff vegetation, arctic vegetation; or,
- referring to specific plant communities, e.g., peat bog or trembling aspen vegetation types.
Vegetation is a broader term than flora, which refers specifically to the plant diversity of an area.
Spatially, vegetation can be thought of as the mosaic of plant communities across the landscape.
The diversity of vegetation for an area can be specified using any of the three descriptive categories noted above, e.g.,
- Alberta has forest, shrub, and grassland vegetation;
- Canada has temperate, boreal and arctic vegetation; or,
- The river valley has spruce and cottonwood riparian vegetation communities.
Vegetation integrates the combined inﬂuence of a variety of environmental factors. The main factors determining vegetation conditions in a specific area are:
- climate: macroclimate has a primary influence on the overall flora – the plants that make up the vegetation.
- organisms: although plants are the key organisms, animals, fungi, and microorganisms influence the resulting vegetation development through various interspecies and habitat relationships.
- topography: determines the movement of surface and soil water, and therefore the moisture and some nutrient availability; also influences microclimate, e.g., aspect, cold air drainage.
- soil parent material: is a primary influence on moisture and nutrient conditions in the substrates within which plants grow.
- time: the length of development time, since either vegetation establishment or significant disturbance of existing vegetation, affects the characteristics of current vegetation.
Vegetation can range from natural to cultural.
- Natural vegetation, the focus of the Canadian National Vegetation Classification programme, is that which develops 'naturally' with little to no influence or modification by humans, except, in some cases, by First Nations peoples (e.g., regular burning to increase certain habitats or food products). Native species characterize natural vegetation.
- Semi-natural vegetation is generally included in the 'natural' landscape, as humans have influenced the natural vegetation in many areas and certain values and services are provided by semi-natural and natural vegetation. Some introduced, i.e., non-native, species are usually a component of semi-natural vegetation.
- Cultural vegetation is planted and/or maintained by humans, often with considerable input of energy. The species involved are often not native to the area.