Glossary

Biome: A biome is a large-scale group of related natural communities. They are like a natural community on a grand, regional scale. They contain many different natural communities. Biomes are not unique to a particular location or even a continent. A combination of various factors are used to distinguish biomes, including climate (particularly rainfall and temperature), altitude, soil, and bedrock geology. There are various versions of the planets biomes, some broader, others having more distinctions. One version distinguishes nine terrestrial biomes on the planet: Rainforest, Temperate Deciduous Forest, Boreal Forest (Taiga), Chaparral, Grassland, Savanna, Desert, and Tundra. Each of these biomes is found on more than one continent. In Wisconsin three biomes meet and overlap: Temperate Deciduous Forest (typical of Eastern U.S.), Prairie (typical of the plains states), and Boreal Forest (typical of much of Canada).

Bioregion or Ecoregion: R egions defined by a combination of factors: plant and animal species, topography, climate, altitude, soil, bedrock geology, groundwater, watersheds, cultural history, current socioeconomic use. Each bioregion is unique to a single location; it is found in only one place. Bioregions contain a variety of natural communities, which they share with other bioregions. Bioregions may contain several watersheds, or several bioregions may be contained in one watershed. There are many ways to divide land into bioregions, depending on choice and relative emphasis of the factors. One bioregional classification lists seven bioregions in Wisconsin: Northwest Forest, Northcentral Forest, Northeast Forest, the Driftless Area, The Central Sands, the Southeast, and the very small St. Croix. The Wisconsin DNR lists sixteen bioregions.

Natural community or biotic community: A natural community is a unique set of interrelating plant and animal species. Natural communities are usually classified by plant type (biotic community) but include a set of animal species adapted to that habitat. Natural communities are not unique to a single location. They can be found in various bioregions and watersheds. There are many different classifications of natural communities in a region such as Wisconsin, some more much more detailed than others. Usually, classifications include only those communities in existence before European settlement. One simple, broad classification lists natural communities: Prairie, Oak Savanna, Southern Hardwood Forest, Pine Savanna, Conifer-Hardwood Forest, Boreal Forest. The Wisconsin DNR lists seventy-six communities.

Tension zone: This is an ecotone area in which two major ecosystems overlap in Wisconsin. In terms of natural communities (plants and animals) this is the most important bioregional distinction in Wisconsin. The zone runs very roughly from northwest/southeast from Polk County to Sheboygan County, although the line curves north and south. Botanists have discovered that species native to boreal regions of Canada tend to have their southern limit in this zone, and species native to the Eastern Forests and Prairie biomes of the United States have their northern limit in that zone. Above that zone, for instance, there are virtually no prairies. Below that zone, most conifers are not native.

W atershed: A watershed is the region of land that drains into one body of water, usually a river, but also a lake or ocean. Theoretically, rain landing anywhere in a watershed will eventually drain into that body of water. Watershed divisions usually run along the ridges of hills and mountains. Each watershed is unique to a single location; it is found in only one place. Watersheds contain a variety of natural communities. They may contain more than one bioregion, and several watersheds may be contained in one bioregion. Watersheds may be defined at small or large scales, from a section of a river (e.g. Upper Fox) to a major river system containing many smaller watershed (e.g. the Mississppi). Major watersheds in Wisconsin include the Wisconsin River (upper, middle, and lower), Fox-Wolf River (Wolf, Upper Fox, and Lower Fox), Chippewa River, and Rock River. All but the Fox-Wolf River are in the larger Mississippi watershed.

Back Home