A habitat is made up of physical factors such as soil, moisture, range of temperature, and availability of light as well as biotic factors such as the availability of food and the presence of predators. A habitat is not necessarily a geographic area—for a parasitic organism it is the body of its host or even a cell within the host's body.
The monotypic habitat occurs in botanical and zoological contexts, and is a component of conservation biology. In restoration ecology of native plant communities or habitats, some invasive species create monotypic stands that replace and/or prevent other species, especially indigenous ones, from growing there. A dominant colonization can occur from retardant chemicals exuded, nutrient monopolization, or from lack of natural controls such as herbivores or climate, that keep them in balance with their native habitats. The yellow starthistle, Centaurea solstitialis, is a botanical monotypic-habitat example of this, currently dominating over 15,000,000 acres (61,000 km2) in California alone. The non-native freshwater zebra mussel, Dreissena polymorpha, that colonizes areas of the Great Lakes and the Mississippi Riverwatershed, without its home-range predator control, is a zoological monotypic-habitat example. Even though its name may seem to imply simplicity as compared with polytypic habitats, the monotypic habitat can be complex.