ecosystem


ecosystem
/ek"oh sis'teuhm, ee"koh-/, n. Ecol.
a system formed by the interaction of a community of organisms with their environment.
[1930-35; ECO- + SYSTEM]

* * *

Complex of living organisms, their physical environment, and all their interrelationships in a particular unit of space.

An ecosystem's abiotic (nonbiological) constituents include minerals, climate, soil, water, sunlight, and all other nonliving elements; its biotic constituents consist of all its living members. Two major forces link these constituents: the flow of energy and the cycling of nutrients. The fundamental source of energy in almost all ecosystems is radiant energy from the sun; energy and organic matter are passed along an ecosystem's food chain. The study of ecosystems became increasingly sophisticated in the later 20th century; it is now instrumental in assessing and controlling the environmental effects of agricultural development and industrialization. See also biome.

* * *

 the complex of living organisms, their physical environment, and all their interrelationships in a particular unit of space.

      A brief treatment of ecosystems follows. For full treatment, see biosphere.

      An ecosystem can be categorized into its abiotic constituents, including minerals, climate, soil, water, sunlight, and all other nonliving elements, and its biotic constituents, consisting of all its living members. Linking these constituents together are two major forces: the flow of energy through the ecosystem, and the cycling of nutrients (nutrient) within the ecosystem.

      The fundamental source of energy in almost all ecosystems is radiant energy from the Sun. The energy of sunlight is used by the ecosystem's autotrophic, or self-sustaining, organisms. Consisting largely of green vegetation, these organisms are capable of photosynthesisi.e., they can use the energy of sunlight to convert carbon dioxide and water into simple, energy-rich carbohydrates. The autotrophs use the energy stored within the simple carbohydrates to produce the more complex organic compounds, such as proteins, lipids, and starches, that maintain the organisms' life processes. The autotrophic segment of the ecosystem is commonly referred to as the producer level.

      Organic matter generated by autotrophs directly or indirectly sustains heterotrophic organisms. Heterotrophs are the consumers of the ecosystem; they cannot make their own food. They use, rearrange, and ultimately decompose the complex organic materials built up by the autotrophs. All animals and fungi are heterotrophs, as are most bacteria and many other microorganisms.

      Together, the autotrophs and heterotrophs form various trophic (feeding) levels in the ecosystem: the producer level, composed of those organisms that make their own food; the primary-consumer level, composed of those organisms that feed on producers; the secondary-consumer level, composed of those organisms that feed on primary consumers; and so on. The movement of organic matter and energy from the producer level through various consumer levels makes up a food chain. For example, a typical food chain in a grassland might be grass (producer) → mouse (primary consumer) → snake (secondary consumer) → hawk (tertiary consumer). Actually, in many cases the food chains of the ecosystem overlap and interconnect, forming what ecologists call a food web. The final link in all food chains is made up of decomposers, those heterotrophs that break down dead organisms and organic wastes. A food chain in which the primary consumer feeds on living plants is called a grazing pathway; that in which the primary consumer feeds on dead plant matter is known as a detritus pathway. Both pathways are important in accounting for the energy budget of the ecosystem.

* * *


Universalium. 2010.

Look at other dictionaries:

  • ecosystem — UK US /ˈiːkəʊˌsɪstəm/ noun [C] ► ENVIRONMENT all the living things in an area and the way they affect each other and the environment: »Three quarters of these cork oak forests could be lost within the decade, threatening jobs and ecosystems. ►… …   Financial and business terms

  • ecosystem — ecosystem. См. экосистема. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • ecosystem — 1935; see ECO (Cf. eco ) + SYSTEM (Cf. system). Perhaps coined by English ecologist Sir Arthur George Tansley (1871 1955) …   Etymology dictionary

  • ecosystem — [n] environment ecological community, environs; concepts 515,673,696 …   New thesaurus

  • ecosystem — ► NOUN ▪ a biological community of interacting organisms and their physical environment …   English terms dictionary

  • ecosystem — [ek′ōsis΄təm, ē′kōsis΄təm] n. [ ECO + SYSTEM] a system made up of a community of animals, plants, and bacteria interrelated together with its physical and chemical environment …   English World dictionary

  • Ecosystem — An ecosystem is a natural unit consisting of all plants, animals and micro organisms(biotic factors) in an area functioning together with all of the non living physical (abiotic) factors of the environment.Christopherson, RW (1996) Geosystems: An …   Wikipedia

  • ecosystem — 01. Any changes made in our [ecosystem] affect all the plants and animals that live there. 02. Destroying one part of the [ecosystem] affects every other part of it. 03. As you wander down the beach, you encounter different tiny [ecosystems],… …   Grammatical examples in English

  • ecosystem — noun Ecosystem is used before these nouns: ↑management, ↑restoration Ecosystem is used after these nouns: ↑ocean …   Collocations dictionary

  • ecosystem — [[t]i͟ːkoʊsɪstəm, AM e̱kə [/t]] ecosystems N COUNT An ecosystem is all the plants and animals that live in a particular area together with the complex relationship that exists between them and their environment. [TECHNICAL] Madagascar s… …   English dictionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.