Closed ecological systems (CES) are
ecosystems that do not rely on matter exchange with any part outside the system.
The term is most often used to describe small,
manmade
Artificiality (the state of being artificial or manmade) is the state of being the product of intentional human manufacture, rather than occurring naturally through processes not involving or requiring human activity.
Connotations
Artificiality ...
ecosystems. Such systems are scientifically interesting and can potentially serve as a
life-support system
A life-support system is the combination of equipment that allows survival in an environment or situation that would not support that life in its absence. It is generally applied to systems supporting human life in situations where the outsid ...
during
space flights, in
space stations or
space habitat
A space habitat (also called a space settlement, space colony, spacestead, space city, orbital habitat, orbital settlement, orbital colony, orbital stead or orbital city) is a more advanced form of living quarters than a space station or habit ...
s.
In a closed ecological system, any waste products produced by one species must be used by at least one other species. If the purpose is to maintain a life form, such as a
mouse
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
or a
human, waste products such as
carbon dioxide,
feces
Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...
and
urine must eventually be converted into
oxygen,
food
Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inge ...
, and
water.
A closed ecological system must contain at least one
autotrophic organism. While both
chemotrophic and
phototrophic organisms are plausible, almost all closed ecological systems to date are based on an autotroph such as green
algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
.
Examples
A closed ecological system for an entire planet is called an
ecosphere.
Man-made closed ecological systems which were created to sustain human life include
Biosphere 2
Biosphere 2 is an American Earth system science research facility located in Oracle, Arizona. Its mission is to serve as a center for research, outreach, teaching, and lifelong learning about Earth, its living systems, and its place in the univers ...
,
MELiSSA, and the BIOS-1, BIOS-2, and
BIOS-3
BIOS-3 is an experimental closed ecosystem at the Institute of Biophysics in Krasnoyarsk, Russia.
Its construction began in 1965, and was completed in 1972. BIOS-3 consists of a underground steel structure suitable for up to three persons, and ...
projects.
Bottle garden
A bottle garden is a type of closed terrarium in which plants are grown. They usually consist of a plastic or glass bottle with a narrow neck and a small opening. Plants are grown inside the bottle with little or no exposure to the outside environ ...
s and
aquarium ecospheres are partially or fully enclosed glass containers that are self-sustaining closed ecosystems that can be made or purchased. They can include tiny
shrimp
Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...
,
algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
,
gravel
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone.
Gravel is classifi ...
, decorative
shells, and ''
Gorgonia''.
In fiction
See also
*
*
*
*
*
*
*
*
*
*
*
*
*
*
References
Emerging technologies
Ecological processes
Systems ecology
{{Space-stub