Closed ecological system
Encyclopedia
The term is most often used to describe small manmade ecosystems. Such systems are scientifically interesting and can potentially serve as a life support system
Life support system
In human spaceflight, a life support system is a group of devices that allow a human being to survive in space.US government space agency NASA,and private spaceflight companies...
during space flights, in space stations or space habitat
Space habitat
A space habitat is a space station intended as a permanent settlement rather than as a simple waystation or other specialized facility...
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 higher life form, such as a mouse
Mouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
or a human
Human
Humans are the only living species in the Homo genus...
, waste products such as carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
, faeces and urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
must eventually be converted into oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
, food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
, and water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
.
A closed ecological system must contain at least one autotroph
Autotroph
An autotroph, or producer, is an organism that produces complex organic compounds from simple inorganic molecules using energy from light or inorganic chemical reactions . They are the producers in a food chain, such as plants on land or algae in water...
ic organism. While both chemotroph
Chemotroph
Chemotrophs are organisms that obtain energy by the oxidation of electron donors in their environments. These molecules can be organic or inorganic . The chemotroph designation is in contrast to phototrophs, which utilize solar energy...
ic and phototroph
Phototroph
Phototrophs are the organisms that carry out photosynthesis to acquire energy. They use the energy from sunlight to convert carbon dioxide and water into organic material to be utilized in cellular functions such as biosynthesis and respiration.Most phototrophs are autotrophs, also known as...
ic organisms are plausible, almost all closed ecological systems to date are based on a phototroph such as green algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
.
Examples
Major (large-scale) closed ecological systems include Biosphere 2Biosphere 2
Biosphere 2 is a structure originally built to be an artificial, materially-closed ecological system in Oracle, Arizona by Space Biosphere Ventures, a joint venture whose principal officers were John P. Allen, inventor and Executive Director, and Margret Augustine, CEO...
, MELiSSA
MELiSSA
The acronym MELiSSA means 'Micro-Ecological Life Support System Alternative' and is a development program of a microbiological and horticultural plant based ecosystem...
, and the BIOS-1, BIOS-2, and BIOS-3
BIOS-3
BIOS-3 is a 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 315-cubic-metre habitat suitable for up to three persons, and was initially used for developing closed ecosystems capable of supporting...
projects.
An ecosphere is a glass enclosed, self-contained and self-sustaining closed ecosystem sold primarily as a gift or experiment. It can include tiny shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
, algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...
, decorative shells, and gorgonia.
Also bottle garden
Bottle garden
A bottle garden is a container similar to a terrarium in which plants are grown. They usually consist of a plastic or glass bottle with a narrow neck and a small opening...
s can act as a closed ecological system.
See also
- BiosphereBiosphereThe biosphere is the global sum of all ecosystems. It can also be called the zone of life on Earth, a closed and self-regulating system...
- Controlled Ecological Life Support SystemControlled Ecological Life Support SystemControlled Ecological Life Support Systems are a type of scientific endeavor to create a self-supporting life support system for space stations and colonies typically through controlled closed ecological systems, such as the BioHome, BIOS-3 and Biosphere 2.-Original concept:CELSS was first...
- EcologyEcologyEcology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
- Eden ProjectEden ProjectThe Eden Project is a visitor attraction in Cornwall in the United Kingdom, including the world's largest greenhouse. Inside the artificial biomes are plants that are collected from all around the world....
- Space colonizationSpace colonizationSpace colonization is the concept of permanent human habitation outside of Earth. Although hypothetical at the present time, there are many proposals and speculations about the first space colony...
- SpomeSpomeA spome is any hypothetical system closed with respect to matter and open with respect to energy capable of sustaining human life indefinitely. The term was coined in 1966 by Isaac Asimov in a paper entitled "There’s No Place Like Spome", published in Atmosphere in Space Cabins and Closed...
- TerraformingTerraformingTerraforming of a planet, moon, or other body is the hypothetical process of deliberately modifying its atmosphere, temperature, surface topography or ecology to be similar to those of Earth, in order to make it habitable by terrestrial organisms.The term is sometimes used more generally as a...
Sources
- "Manmade Closed Ecological Systems." I. I. Gitelson, G. M. Lisovsky and R. D. MacElroy. Taylor & Francis (2003) ISBN 0-415-29998-5.