Classification
| Tundra Taiga Temperate broadleaf and mixed forest Temperate steppe Subtropical rainforest | Mediterranean Tropical and subtropical moist broadleaf forests Desert Xeric shrubland Dry steppe Semidesert | Grass savanna Tree savanna Tropical and subtropical dry forest Tropical rainforest Alpine tundra Montane forests |
Much of the work on vegetation classification comes from European and North American ecologists, and they have fundamentally different approaches. In North America, vegetation types are based on a combination of the following criteria: climate pattern, plant habit, phenology and/or growth form, and dominant species. In the current US standard (adopted by the Federal Geographic Data Committee (FGDC), and originally developed by UNESCO and The Nature Conservancy), the classification is hierarchical and incorporates the non-floristic criteria into the upper (most general) five levels and limited floristic criteria only into the lower (most specific) two levels. In Europe, classification often relies much more heavily, sometimes entirely, on floristic (species) composition alone, without explicit reference to climate, phenoloogy or growth forms. It often emphasizes indicator or diagnostic species which separate one type from another.
In the FGDC standard, the hierarchy levels, from most general to most specific, are: system, class, subclass, group, formation, alliance, and association. The lowest level, or association, is thus the most precisely defined, and incorporates the names of the dominant one to three (usually two) species of the type. An example of a vegetation type defined at the level of class might be "Forest, canopy cover > 60%"; at the level of a formation as "Winter-rain, broad-leaved, evergreen, sclerophyllous, closed-canopy forest"; at the level of alliance as "Arbutus menziesii forest"; and at the level of association as "Arbutus menziesii-Lithocarpus densiflora forest", referring to Pacific madrone-tanoak forests which occur in California and Oregon, USA. In practice, the levels of the alliance and/or association are the most often used, particularly in vegetation mapping, just as the Latin binomial is most often used in discussing particular species in axonomy and in general communication.
Victoria in Australia classifies its vegetation by Ecological Vegetation Class.
Read more about this topic: Vegetation