This module focuses on the biota of watersheds. Biota refers to the plants, or flora, and animals, or fauna, of an area. The flora and fauna of watersheds play important roles in maintaining watershed function and can be important indicators of changes within the system.
Biota can be studied on several scales within a hierarchy. The study of an individual organism, or single plant or animal, is the finest scale. Unique plants and animals are differentiated from one another as different species. A single species is defined as a group of individuals that can successfully breed with one another. Groups of individuals of the same species are populations. Communities are comprised of populations of several different species living together. Ecosystems are communities of different species interacting as well as the surrounding physical, non-living environment.
Biomes are major classifications of ecological communities, recognizable on a continental or global scale. Climate plays a major role in the plants and animals which comprise biomes and where they occur on the globe. The diagram below shows the major biomes of the earth and the temperature and precipitation conditions associated with them.
Temperature is read along the x-axis (along the bottom of the graphic) and precipitation is read along the y-axis (the left side of the graphic). For example, the tundra biome, depicted in light blue on the graphic, occurs under conditions of very low average temperatures and low annual precipitation. Tropical rain forests occur under high temperatures and high annual precipitation.