Natural community (Ecology (collection))

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Ecology Theory (main)

Natural Community

April 9, 2009, 3:35 pm
October 20, 2011, 9:48 pm

A natural community is an interactive assemblage of organisms, their physical environment, and the natural processes that affect them. Environmental factors such as soil type, bedrock type, moisture level, slope, slope aspect, climate, and the natural disturbance regime play a key role in determining a species' ability to survive there. The organisms within a natural community include: plants, animals, fungus, and microorganisms. Natural communities occur in patterns throughout the earth and range in size from thousands of acres, such as a Northern Hardwood Forest, to less than one acre, such as a seep. Natural communities change over geological and evolutionary time, and are not static.

Natural communities classification is used as a management tool. By grouping complex systems into categories, people are able to process information about those systems which may otherwise prove difficult. Ecologists categorize complex natural systems to better understand spatial patterns in nature.

History of Natural Communities Classification

Scientist Frederic Clements (1916;1928) developed the ‘organismic concept’ which recognized that communities were definable, with species grouped repeatedly and regularly in similar environmental conditions.

Scientist Henry Gleason (1917;1926;1939) responded to Clements’ concept with the ‘individualistic concept’ which stated that each species responds to their environmental conditions independently. Therefore, the resulting combination of species at any place on earth is variable.

Scientists Whittaker and Levin (1953;1977) combined the concepts outlined above to create the ‘climax pattern hypothesis’ which recognized that species are grouped together repeatedly and predictably over considerable areas, yet there are areas between these communities where this predictability does not occur.

Scientists from The Nature Conservancy helped to establish the first state Natural Heritage Program in 1974 in part to categorize natural communities in the United States. By 2001 the program grew to all fifty states, Canada, and Latin America. At that time, NatureServe, in Arlington, Virginia, took over the mission to provide a scientific basis for conservation, and continues to be one of the most comprehensive sources for information on rare and endangered species.

Uses of Natural Communities Classification

The classification of patterns of organisms in the landscape into natural communities is used by a variety of practitioners. Managers of a natural area may use data collected on natural community types to create maps to guide decision making. This is helpful when determining rare or severely impacted communities. One important application is in forestry. The Nature Conservancy publication “Natural Dynamics Silviculture” (PDF 1.2MB) applies the use of natural communities classification to forestry.

Natural community classification can aid in conservation planning at the local, regional, and ecoregional scale, and can be useful in predicting species occurrences across entire geographic ranges.

Challenges of Classification

This classification concept does not allow for areas which have been heavily impacted by humans, or that are in a state of flux. In addition, the classification is also heavily dominated by plant species due to their indication of the environmental conditions listed above. The strong emphasis to classify based on plant species may be limiting when determining what is actually happening on site because it does not take into consideration other living organisms.

Further Reading

  • Sorenson, E.R., Thompson, E.H., 2005. Wetland, Woodland, Wildland: A Guide to the Natural Communities of Vermont. The Nature Conservancy and the Vermont Department of Fish and Wildlife: [1]
  • Maybury, Kathleen P., editor. 1999. Seeing the Forest and the Trees: Ecological Classification for Conservation. {Link} The Nature Conservancy: Arlington, Virginia.
  • Whittaker, R.H.1962. Classification of Natural Communities. New York Botanical Garden Press: New York.

This article was initiated as part of the Student Science Communication Project. Graduate student author: Amanda Garland, Reviewer: Elizabeth Thompson. Class: Conservation Techniques and Approaches.


Garland, A. (2011). Natural Community. Retrieved from