Agroecosystem in Croton-on-Hudson, New York in Westchester County. Intercropped tomatoes, basil, peppers and eggplants.

An agroecosystem is the basic unit of study for an agroecologist. It is somewhat arbitrarily defined as a spatially and functionally coherent unit of agricultural activity, and includes the living and nonliving components involved in that unit as well as their interactions. ^[1]

An agroecosystem can be viewed as a subset of a conventional ecosystem. As the name implies, at the core of an agroecosystem lies the human activity of agriculture. However, an agroecosystem is not restricted to the immediate site of agricultural activity (e.g. the farm), but rather includes the region that is impacted by this activity, usually by changes to the complexity of species assemblages and energy flows, as well as to the net nutrient balance. Traditionally an agroecosystem, particularly one managed intensively, is characterized as having a simpler species composition and simpler energy and nutrient flows than "natural" ecosystem. ^[2] Likewise, agroecosystems are often associated with elevated nutrient input, ^[3] much of which exits the farm leading to eutrophication of connected ecosystems not directly engaged in agriculture.

One of the major efforts of disciplines such as agroecology is to promote management styles that blur the distinction between agroecosystems and "natural" ecosystems, both by decreasing the impact of agriculture (increasing the biological and trophic complexity of the agricultural system as well as decreasing the nutrient inputs/outflow) and by increasing awareness that "downstream" effects extend agroecosystems beyond the boundaries of the farm (e.g. the Corn Belt agroecosystem includes the hypoxic zone in the Gulf of Mexico). In the first case, polyculture or buffer strips for wildlife habitat can restore some complexity to a cropping system, while organic farming can reduce nutrient inputs. Efforts of the second type are most common at the watershed scale. An example is the National Association of Conservation Districts' Lake Mendota Watershed Project, which seeks to reduce runoff from the agricultural lands feeding into the lake with the aim of reducing algal blooms. ^[4]

[edit] See also

• Agriculture
• Agroecological restoration
• Agroecology
• Agroecosystem analysis
• Agrophysics
• Ecology of contexts
• Polyculture

[edit] References

• Loucks, Orie (Novermber 1977). "Emergence of Research on Agro-Ecosystems". Annual Review of Ecology and Systematics 8: 173-192. http://arjournals.annualreviews.org/doi/pdf/10.1146/annurev.es.08.110177.001133?cookieSet=1. Retrieved December 7, 2004. 

[edit] Notes

1. ^ Agro-ecosystem Health Project. 1996. Agroecosystem health. University of Guelph, Guelph, Canada.
2. ^ Elske van de Fliert and Ann R. Braun. 1999. Farmer Field School for Integrated Crop Management of Sweetpotato. Field guides and Technical Manual. Bogor, Indonesia: International Potato Center. ISBN: 92-9060-216-3. http://www.eseap.cipotato.org/MF-ESEAP/Abstract/FFS-ICM-SP-Ind.htm
3. ^ Agroecosystem Management for Improved Human Health: Applying principles of integrated pest management to people. D. G. Peden. Published in New Directions in Animal Production Systems. Proceedings of the Annual Meeting of the Canadian Society of Animal Science, July 5-8, 1998, Vancouver, British Columbia, Canada. Edited by R. Blair, R. Rajamahendran, L.S. Stephens, M.Y. Yang. http://www.idrc.ca/en/ev-3443-201-1-DO_TOPIC.html
4. ^ TMDL Case Study: Wisconsin http://www.nacdnet.org/policy/environment/water/tmdl/casestudies/wisconsin.phtml