Ecosystem

Ecosystem

Overview
An ecosystem is a biological environment
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

 consisting of all the organisms living in a particular area, as well as all the nonliving (abiotic), physical components of the environment with which the organisms interact, such as air, soil, water and sunlight.

The entire array of organisms inhabiting a particular ecosystem is called a community
Community (ecology)
In ecology, a community is an assemblage of two or more populations of different species occupying the same geographical area. The term community has a variety of uses...

. The number of species making up such a community may vary from a myriad to a single species such as Desulforudis.
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Encyclopedia
An ecosystem is a biological environment
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

 consisting of all the organisms living in a particular area, as well as all the nonliving (abiotic), physical components of the environment with which the organisms interact, such as air, soil, water and sunlight.

Overview


The entire array of organisms inhabiting a particular ecosystem is called a community
Community (ecology)
In ecology, a community is an assemblage of two or more populations of different species occupying the same geographical area. The term community has a variety of uses...

. The number of species making up such a community may vary from a myriad to a single species such as Desulforudis. In a typical ecosystem, plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s and other photosynthetic
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...

 organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...

s are the producers that provide the food. Ecosystems can be permanent or temporary. Ecosystems usually form a number of food web
Food web
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...

s.

Ecosystems are functional units consisting of living things in a given area, non-living chemical and physical factors of their environment, linked together through nutrient cycle and energy flow."
  • Natural
    • Terrestrial ecosystem
      Terrestrial ecosystem
      A terrestrial ecosystem is an ecosystem found only on a landform. Four primary terrestrial ecosystems exist: tundra, taiga, temperate deciduous forest, and grassland...

    • Aquatic ecosystem
      Aquatic ecosystem
      An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems....

    • Lentic, the ecosystem of a lake, pond or swamp.
    • Lotic
      Lotic ecosystem
      A lotic ecosystem is the ecosystem of a river, stream or spring. Included in the environment are the biotic interactions as well as the abiotic interactions ....

      , the ecosystem of a river, stream or spring.
  • Artificial
    Artificial
    See also: Synthetic ' or ' may refer to:* Artificial beaches* Artificial chemistry* Artificial consciousness* Artificial creation* Artificial elements* Artificial flower* Artificial food* Artificial fuel* Artificial harmonic...

    , ecosystems created by humans.


Central to the ecosystem concept is the idea that living organisms interact with every other element in their local environment
Environment (biophysical)
The biophysical environment is the combined modeling of the physical environment and the biological life forms within the environment, and includes all variables, parameters as well as conditions and modes inside the Earth's biosphere. The biophysical environment can be divided into two categories:...

. Eugene Odum
Eugene Odum
Eugene Pleasants Odum was an American scientist known for his pioneering work on ecosystem ecology. He wrote the first ecology textbook: Fundamentals of Ecology....

, a founder of ecology
Ecology
Ecology 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...

, stated: "Any unit that includes all of the organisms (ie: the "community") in a given area interacting with the physical environment so that a flow of energy leads to clearly defined trophic structure, biotic diversity, and material cycles (i.e.: exchange of materials between living and nonliving parts) within the system is an ecosystem.

Etymology


The term ecosystem was coined in 1930 by Roy Clapham to mean the combined physical and biological components of an environment. British ecologist Arthur Tansley
Arthur Tansley
Sir Arthur George Tansley FRS was an English botanist who was a pioneer in the science of ecology. He obtained his degree in Biological Science in 1896, with specialization in botany and zoology. From the start, he was much influenced by the Danish plant ecologist Eugenius Warming. He championed...

 later refined the term, describing it as "The whole system, … including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment". Tansley regarded ecosystems not simply as natural units, but as mental isolates. Tansley later defined the spatial extent of ecosystems using the term ecotope
Ecotope
Ecotopes are the smallest ecologically-distinct landscape features in a landscape mapping and classification system. As such, they represent relatively homogeneous, spatially-explicit landscape functional units that are useful for stratifying landscapes into ecologically distinct features for the...

.

Examples of ecosystems


  • Agroecosystem
    Agroecosystem
    An agroecosystem is the basic unit of study for an agroecologist, and 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.An agroecosystem can be...

  • Aquatic ecosystem
    Aquatic ecosystem
    An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems....

  • Chaparral
    Chaparral
    Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...

  • Coral reef
    Coral reef
    Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...

  • Desert
    Desert
    A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...

  • Forest
    Forest
    A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

  • Farm
    Farm
    A farm is an area of land, or, for aquaculture, lake, river or sea, including various structures, devoted primarily to the practice of producing and managing food , fibres and, increasingly, fuel. It is the basic production facility in food production. Farms may be owned and operated by a single...

  • Greater Yellowstone Ecosystem
    Greater Yellowstone Ecosystem
    The Greater Yellowstone Ecosystem is one of the last remaining large, nearly intact ecosystems in the northern temperate zone of the Earth and is partly located in Yellowstone National Park. Conflict over management has been controversial, and the area is a flagship site among conservation groups...

  • Human ecosystem
    Human ecosystem
    Human ecosystems are complex cybernetic systems that are increasingly being used by ecological anthropologists and other scholars to examine the ecological aspects of human communities in a way that integrates multiple factors as economics, socio-political organization, psychological factors, and...

  • Large marine ecosystem
    Large marine ecosystem
    Large marine ecosystems are regions of the world's oceans, encompassing coastal areas from river basins and estuaries to the seaward boundaries of continental shelves and the outer margins of the major ocean current systems...

  • Littoral zone
  • Lotic
  • Marine ecosystem
    Marine ecosystem
    Marine ecosystems are among the largest of Earth's aquatic ecosystems. They include oceans, salt marsh and intertidal ecology, estuaries and lagoons, mangroves and coral reefs, the deep sea and the sea floor. They can be contrasted with freshwater ecosystems, which have a lower salt content. Marine...

  • Pond ecosystem
  • Prairie
    Prairie
    Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...

  • Rainforest
    Rainforest
    Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...

  • Riparian zone
    Riparian zone
    A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by...

  • Savanna
    Savanna
    A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...

  • Steppe
    Steppe
    In physical geography, steppe is an ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes...

  • Subsurface Lithoautotrophic Microbial Ecosystem
    Subsurface Lithoautotrophic Microbial Ecosystem
    Subsurface Lithoautotrophic Microbial Ecosystems, or "SLIMEs" , are defined by Edward O. Wilson as "unique assemblages of bacteria and fungi that occupy pores in the interlocking mineral grains of igneous rock beneath Earth's surface."-External links:* * *...

  • Taiga
    Taiga
    Taiga , also known as the boreal forest, is a biome characterized by coniferous forests.Taiga is the world's largest terrestrial biome. In North America it covers most of inland Canada and Alaska as well as parts of the extreme northern continental United States and is known as the Northwoods...

  • Tundra
    Tundra
    In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...

  • Urban ecosystem
    Urban ecosystem
    Urban ecosystems are the cities, towns, and urban strips constructed by humans.This is the growth in the urban population and the supporting built infrastructure has affected both urban environments and also on areas which surround urban areas...



Biomes



Biome
Biome
Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...

s are a classification of globally similar areas, including ecosystems, such as ecological communities
Community (ecology)
In ecology, a community is an assemblage of two or more populations of different species occupying the same geographical area. The term community has a variety of uses...

 of plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s and animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...

s, soil organisms
Soil biology
Soil biology is the study of microbial and faunal activity and ecology in soil. These organisms include earthworms, nematodes, protozoa, fungi, bacteria and different arthropods...

 and climatic
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...

 conditions. Biomes are in part defined based on factors such as plant structures (such as trees, shrubs and grasses), leaf types (such as broadleaf and needleleaf), plant spacing (forest, woodland, savanna) and climate. Unlike ecozone
Ecozone
An ecozone is the broadest biogeographic division of the Earth's land surface, based on distributional patterns of terrestrial organisms.Ecozones delineate large areas of the Earth's surface within which organisms have been evolving in relative isolation over long periods of time, separated from...

s, biomes are not defined by genetic, taxonomic or historical similarities. Biomes are often identified with particular patterns of ecological succession
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...

 and climax vegetation
Climax vegetation
Climax vegetation is the vegetation which establishes itself on a given site for given climatic conditions in the absence of anthropic action after a long time ....

.

A fundamental classification of biomes is:
  1. Terrestrial (land) biomes.
  2. Freshwater biomes.
  3. Marine biomes.

Classification





Ecosystems have become particularly important politically
Politics
Politics is a process by which groups of people make collective decisions. The term is generally applied to the art or science of running governmental or state affairs, including behavior within civil governments, but also applies to institutions, fields, and special interest groups such as the...

, since the Convention on Biological Diversity
Convention on Biological Diversity
The Convention on Biological Diversity , known informally as the Biodiversity Convention, is an international legally binding treaty...

 (CBD) - ratified by 192 countries - defines "the protection of ecosystems, natural habitats and the maintenance of viable populations of species in natural surroundings" as a commitment of ratifying countries. This has created the political necessity to spatially identify ecosystems and somehow distinguish among them. The CBD defines an "ecosystem" as a "dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit".

With the need of protecting ecosystems
Environmental protection
Environmental protection is a practice of protecting the environment, on individual, organizational or governmental level, for the benefit of the natural environment and humans. Due to the pressures of population and our technology the biophysical environment is being degraded, sometimes permanently...

, the political need arose to describe and identify them efficiently. Vreugdenhil et al. argued that this could be achieved most effectively by using a physiognomic-ecological classification system, as ecosystems are easily recognizable in the field as well as on satellite images. They argued that the structure and seasonality of the associated vegetation
Vegetation
Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader...

, or flora
Flora
Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animals is fauna.-Etymology:...

, complemented with ecological data (such as elevation, humidity, and drainage), are each determining modifiers that separate partially distinct sets of species. This is true not only for plant species, but also for species of animals, fungi and bacteria. The degree of ecosystem distinction is subject to the physiognomic modifiers that can be identified on an image and/or in the field. Where necessary, specific fauna
Fauna
Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...

 elements can be added, such as seasonal concentrations of animals and the distribution of coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...

s.

Several physiognomic-ecological classification systems are available:
  • Physiognomic-Ecological Classification of Plant Formations of the Earth: a system based on the 1974 work of Mueller-Dombois and Heinz Ellenberg
    Heinz Ellenberg
    Heinz Ellenberg was a German biologist, botanist and ecologist. Ellenberg was an advocate of viewing ecological systems through holistic means.- Life :...

    , and developed by UNESCO
    UNESCO
    The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations...

    . This classification "describes the above-ground or underwater vegetation structures and cover as observed in the field, described as plant life forms. This classification is fundamentally a species-independent physiognomic, hierarchical vegetation classification system which also takes into account ecological factors such as climate, elevation, human influences such as grazing, hydric regimes and survival strategies such as seasonality. The system was expanded with a basic classification for open water formations".
  • Land Cover Classification System (LCCS), developed by the Food and Agriculture Organization
    Food and Agriculture Organization
    The Food and Agriculture Organization of the United Nations is a specialised agency of the United Nations that leads international efforts to defeat hunger. Serving both developed and developing countries, FAO acts as a neutral forum where all nations meet as equals to negotiate agreements and...

     (FAO).
  • Forest-Range Environmental Study Ecosystems
    Forest-Range Environmental Study Ecosystems
    Forest-Range Environmental Study Ecosystems, known as FRES, are a classification system for defining ecosystems that was developed by the United States Forest Service as a management tool for lands under there control, primarily in the American West, but for the entire lower 48...

     (FRES) developed by the United States Forest Service
    United States Forest Service
    The United States Forest Service is an agency of the United States Department of Agriculture that administers the nation's 155 national forests and 20 national grasslands, which encompass...

     for use in the United States
    United States
    The United States of America is a federal constitutional republic comprising fifty states and a federal district...

    .


Several aquatic classification systems are available, and an effort is being made by the United States Geological Survey
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...

 (USGS) and the Inter-American Biodiversity Information Network
Inter-American Biodiversity Information Network
The Inter-American Biodiversity Information Network is a network dedicated to the adoption and promotion of ecoinformatics standards and protocols in all the countries of the Americas, thus facilitating the sound use of biological information for conservation and sustainable use of biodiversity...

 (IABIN) to design a complete ecosystem classification system that will cover both terrestrial and aquatic ecosystems.

From a philosophy of science
Philosophy of science
The philosophy of science is concerned with the assumptions, foundations, methods and implications of science. It is also concerned with the use and merit of science and sometimes overlaps metaphysics and epistemology by exploring whether scientific results are actually a study of truth...

 perspective, ecosystems are not discrete units of nature that simply can be identified using the most "correct" type of classification approach. In agreement with the definition by Tansley ("mental isolates"), any attempt to delineate or classify ecosystems should be explicit about the observer
Observation
Observation is either an activity of a living being, such as a human, consisting of receiving knowledge of the outside world through the senses, or the recording of data using scientific instruments. The term may also refer to any data collected during this activity...

/analyst
Analyst
Analyst generally is a term for an individual of whom or which the primary function is a deep examination of a specific, limited area and may mean:* Accounting analyst, an accounting analyst evaluates and interprets public company financial statements...

 input in the classification including its normative
Norm (philosophy)
Norms are concepts of practical import, oriented to effecting an action, rather than conceptual abstractions that describe, explain, and express. Normative sentences imply “ought-to” types of statements and assertions, in distinction to sentences that provide “is” types of statements and assertions...

 rationale
Rationale
A rationale is a liturgical vestment worn by clergy, in particular by Bishops, in the Roman Catholic Church which uses full vestments. It is humeral ornament, a counterpart to the Pallium, and is worn over the chasuble...

.

Ecosystem services


Ecosystem services are “fundamental life-support services upon which human civilization depends,”i and can be direct or indirect. Examples of direct ecosystem services are: pollination
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...

, wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

 and erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

 prevention. Indirect services could be considered climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...

 moderation, nutrient cycle
Nutrient cycle
A nutrient cycle is the movement and exchange of organic and inorganic matter back into the production of living matter. The process is regulated by food web pathways that decompose matter into mineral nutrients. Nutrient cycles occur within ecosystems...

s and detoxifying natural substances. The services and goods an ecosystem provides are often undervalued as many of them are without market value. Broad examples include:
  • Regulating (climate, floods, nutrient balance, water filtration)
  • Provisioning (food, medicine, fur, minerals)
  • Cultural (science, spiritual, ceremonial, recreation, aesthetic)
  • Supporting (nutrient cycling, photosynthesis, soil formation).

Ecosystem legal rights


Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

's new constitution of 2008 is the first in the world to recognize legally enforceable Rights of Nature, or ecosystem rights.

The borough of Tamaqua, Pennsylvania
Tamaqua, Pennsylvania
Tamaqua is a borough in eastern Schuylkill County, Pennsylvania, in the United States. The borough, located in Northeastern Pennsylvania's Coal Region, had a population of 7,107 as of the 2010 U.S...

 passed a law giving ecosystems legal rights. The ordinance establishes that the municipal government or any Tamaqua resident can file a lawsuit on behalf of the local ecosystem. Other townships, such as Rush, followed suit and passed their own laws.

This is part of a growing body of legal opinion proposing 'wild law
Wild law
The term ‘wild law’ was first coined by Cormac Cullinan, to refer to human laws that are consistent with Earth jurisprudence. A wild law is a law made by people to regulate human behaviour that privileges maintaining the integrity and functioning of the whole Earth community in the long term, over...

'. Wild law, a term coined by Cormac Cullinan
Cormac Cullinan
Cormac Cullinan is a practising environmental attorney and author based in Cape Town, South Africa. He is a director of the leading South African environmental law firm, Cullinan & Associates Inc, and Chief Executive Officer of EnAct International, an environmental governance consultancy...

 (a lawyer based in South Africa), would cover birds and animals, rivers and deserts.

Function and biodiversity



From an anthropocentric
Anthropocentrism
Anthropocentrism describes the tendency for human beings to regard themselves as the central and most significant entities in the universe, or the assessment of reality through an exclusively human perspective....

 point of view, some people perceive ecosystems as production units that produce goods and services, such as wood by forest ecosystems and grass for cattle by natural grasslands. Meat from wild animals, often referred to as bush meat in Africa, has proven to be extremely successful under well-controlled management schemes in South Africa and Kenya. Much less successful has been the discovery and commercialization of substances of wild organism for pharmaceutical purposes. Services derived from ecosystems are referred to as ecosystem services. They may include
  1. Facilitating the enjoyment of nature, which may generate many forms of income and employment in the tourism sector, often referred to as eco-tourisms,
  2. Water retention, thus facilitating a more evenly distributed release of water,
  3. Soil protection, open-air laboratory for scientific research, etc.


A greater degree of species or biological diversity - commonly referred to as Biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

 - of an ecosystem may contribute to greater resilience of an ecosystem, because there are more species present at a location to respond to change and thus "absorb" or reduce its effects. “Some theories predict that biodiversity will promote ecosystem integrity in changing climates, because high diversity ensures that functional groups will retain at least one species able to tolerate altered condition."
This reduces the effect before the ecosystem's structure is fundamentally changed to a different state. One hypothesis about this is the Rivet Poper Hypothesis. According to Paul and Anne Ehrlich “the diversity of life is something like the rivets on an airplane. Each species plays a small but significant role in the working of the whole, and the loss of any rivet weakens the plane by a small but measurable amount. Pop too many rivets and the plane will crash that is, some vital function will collapse." They are saying if too many species die out then some sort of vital function of the ecosystem such as a food web would collapse causing the ecosystem to fail. However rivets come in different sizes and have different critical functions in construction, when thinking about species as rivets the variety and distribution in the overall structure is important.

This is not universally the case and there is no proven relationship between the species diversity of an ecosystem and its ability to provide goods and services on a sustainable level: Humid tropical forests produce very few goods and direct services and are extremely vulnerable to change, while many temperate forests readily grow back to their previous state of development within a lifetime after felling or a forest fire. Some grasslands have been sustainably exploited for thousands of years (Mongolia, Africa, European peat and mooreland communities).

The study of ecosystems




Ecosystem dynamics


Introduction of new elements, whether biotic
Biotic component
Biotic components are the living things that shape an ecosystem. A biotic factor is any living component that affects another organism, including animals that consume the organism in question, and the living food that the organism consumes. Each biotic factor needs energy to do work and food for...

 or abiotic, into an ecosystem tend to have a disruptive effect. In some cases, this can lead to ecological collapse or "trophic cascading" and the death of many species within the ecosystem. Under this deterministic vision, the abstract notion of ecological health attempts to measure the robustness and recovery capacity for an ecosystem; i.e. how far the ecosystem is away from its steady state.

Often, however, ecosystems have the ability to rebound from a disruptive agent. The difference between collapse or a gentle rebound is determined by two factors—the toxicity
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...

 of the introduced element and the resiliency
Resilience (ecology)
In ecology, resilience is the capacity of an ecosystem to respond to a perturbation or disturbance by resisting damage and recovering quickly. Such perturbations and disturbances can include stochastic events such as fires, flooding, windstorms, insect population explosions, and human activities...

 of the original ecosystem.

Ecosystems are primarily governed by stochastic (chance) events, the reactions these events provoke on non-living materials and the responses by organisms to the conditions surrounding them. Thus, an ecosystem results from the sum of individual responses of organisms to stimuli from elements in the environment.The presence or absence of populations merely depends on reproductive and dispersal success, and population levels fluctuate in response to stochastic events. As the number of species in an ecosystem is higher, the number of stimuli is also higher. Since the beginning of life organisms have survived continuous change through natural selection of successful feeding, reproductive and dispersal behavior. Through natural selection the planet's species have continuously adapted to change through variation in their biological composition and distribution. Mathematically it can be demonstrated that greater numbers of different interacting factors tend to dampen fluctuations in each of the individual factors.

Given the great diversity among organisms on earth, most ecosystems only changed very gradually, as some species would disappear while others would move in. Locally, sub-populations continuously go extinct, to be replaced later through dispersal of other sub-populations. Stochastists do recognize that certain intrinsic regulating mechanisms occur in nature. Feedback and response mechanisms at the species level regulate population levels, most notably through territorial behaviour. Andrewatha and Birch suggest that territorial behaviour tends to keep populations at levels where food supply is not a limiting factor. Hence, stochastists see territorial behaviour as a regulatory mechanism at the species level but not at the ecosystem level. Thus, in their vision, ecosystems are not regulated by feedback and response mechanisms from the ecosystem itself and there is no such thing as a balance of nature.

If ecosystems are governed primarily by stochastic
Stochastic
Stochastic refers to systems whose behaviour is intrinsically non-deterministic. A stochastic process is one whose behavior is non-deterministic, in that a system's subsequent state is determined both by the process's predictable actions and by a random element. However, according to M. Kac and E...

 processes, through which its subsequent state would be determined by both predictable and random actions, they may be more resilient to sudden change than each species individually. In the absence of a balance of nature, the species composition of ecosystems would undergo shifts that would depend on the nature of the change, but entire ecological collapse would probably be infrequent events.

The theoretical ecologist
Theoretical ecology
Theoretical ecology is the scientific discipline devoted to the study of ecological systems using theoretical methods such as simple conceptual models, mathematical models, computational simulations, and advanced data analysis...

 Robert Ulanowicz
Robert Ulanowicz
Robert Edward Ulanowicz is an American theoretical ecologist and philosopher who is best known for his search for a unified theory of ecology. He was born September 17, 1943 in Baltimore, Maryland....

 has used information theory
Information theory
Information theory is a branch of applied mathematics and electrical engineering involving the quantification of information. Information theory was developed by Claude E. Shannon to find fundamental limits on signal processing operations such as compressing data and on reliably storing and...

 tools to describe the structure of ecosystems, emphasizing mutual information (correlations) in studied systems. Drawing on this methodology and prior observations of complex ecosystems, Ulanowicz depicts approaches to determining the stress levels on ecosystems and predicting system reactions to defined types of alteration in their settings (such as increased or reduced energy flow, and eutrophication
Eutrophication
Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...

.

In addition, Eric Sanderson has developed the Muir web, based on experience on the Mannahatta project. This graphical schematic shows how different species are connected to each other, not only regarding their position in the food chain
Food chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...

, but also regarding other services, i.e. provisioning of shelter, ...
See also: Relational order theories
Relational order theories
A number of independent lines of research depict the universe, including the social organization of living creatures which is of particular interest to humans, as systems, or networks, of relationships....

, as to fundamentals of life organization

Ecosystem ecology


Ecosystem ecology
Ecosystem ecology
Ecosystem ecology is the integrated study of biotic and abiotic components of ecosystems and their interactions within an ecosystem framework. This science examines how ecosystems work and relates this to their components such as chemicals, bedrock, soil, plants, and animals.Ecosystem ecology...

 is the integrated study of biotic
Life
Life is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...

 and abiotic components of ecosystems and their interactions within an ecosystem framework. This science
Science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...

 examines how ecosystems work and relates this to their components such as chemicals, bedrock
Bedrock
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...

, soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

, plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s, and animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...

s. Ecosystem ecology examines physical and biological structure and examines how these ecosystem characteristics interact.

See also



  • Biodiversity
    Biodiversity
    Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

  • Biodiversity Action Plan
    Biodiversity Action Plan
    A Biodiversity Action Plan is an internationally recognized program addressing threatened species and habitats and is designed to protect and restore biological systems. The original impetus for these plans derives from the 1992 Convention on Biological Diversity...

  • Biogeochemical cycle
    Biogeochemical cycle
    In ecology and Earth science, a biogeochemical cycle or substance turnover or cycling of substances is a pathway by which a chemical element or molecule moves through both biotic and abiotic compartments of Earth. A cycle is a series of change which comes back to the starting point and which can...

  • Biocoenosis
    Biocoenosis
    A biocoenosis , coined by Karl Möbius in 1877, describes the interacting organisms living together in a habitat . This term is rarely used in English, as this concept has not been popularized in Anglophone countries...

  • Biome
    Biome
    Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...

  • Biosphere
    Biosphere
    The 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...

  • Biosphere 2
    Biosphere 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...

  • Business ecosystem
    Business ecosystem
    Starting in the early 1990s James F. Moore originated the strategic planning concept of a business ecosystem, now widely adopted in the high tech community...

  • Carbon sequestration in terrestrial ecosystems
    Carbon Sequestration in Terrestrial Ecosystems
    Carbon sequestration by terrestrial ecosystems is the net removal of carbon dioxide from the atmosphere or the avoidance of carbon dioxide emissions from terrestrial ecosystems into the atmosphere. The removal process includes CO2 uptake from the atmosphere by all chlorophyllous plants, through...

  • Close to nature forestry
    Close to nature forestry
    Close to nature forestry is a theory and practice that takes the forest as an ecosystem and manages it as such. It is based in reduced human intervention, that should be directed to accelerate the processes that nature would do by itself more slowly. It aims at overcoming the divorce between...

  • Complex system
    Complex system
    A complex system is a system composed of interconnected parts that as a whole exhibit one or more properties not obvious from the properties of the individual parts....

  • Earth Science
    Earth science
    Earth science is an all-embracing term for the sciences related to the planet Earth. It is arguably a special case in planetary science, the Earth being the only known life-bearing planet. There are both reductionist and holistic approaches to Earth sciences...

  • Ecological economics
    Ecological economics
    Image:Sustainable development.svg|right|The three pillars of sustainability. Clickable.|275px|thumbpoly 138 194 148 219 164 240 182 257 219 277 263 291 261 311 264 331 272 351 283 366 300 383 316 394 287 408 261 417 224 424 182 426 154 423 119 415 87 403 58 385 40 368 24 347 17 328 13 309 16 286 26...

  • Ecological yield
    Ecological yield
    Ecological yield is the harvestable population growth of an ecosystem. It is most commonly measured in forestry;sustainable forestry is defined as that which does not harvest more wood in a year than has grown in that year, within a given patch of forest....

  • Ecology
    Ecology
    Ecology 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...

  • Ecoregion
    Ecoregion
    An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...

  • Ecosystem diversity
    Ecosystem diversity
    Ecosystem diversity refers to the diversity of a place at the level of ecosystems. The term differs from biodiversity, which refers to variation in species rather than ecosystems...

  • Ecosystem ecology
    Ecosystem ecology
    Ecosystem ecology is the integrated study of biotic and abiotic components of ecosystems and their interactions within an ecosystem framework. This science examines how ecosystems work and relates this to their components such as chemicals, bedrock, soil, plants, and animals.Ecosystem ecology...

  • Ecosystem engineer
    Ecosystem engineer
    An ecosystem engineer is any organism that creates or modifies habitats. Jones et al. identified two different types of ecosystem engineers:...

  • Ecosystem management
    Ecosystem management
    Ecosystem management is a process that aims to conserve major ecological services and restore natural resources while meeting the socioeconomic, political and cultural needs of current and future generations. The principal objective of ecosystem management is the efficient maintenance, and ethical...

  • Ecosystem model
    Ecosystem model
    An ecosystem model is an abstract, usually mathematical, representation of an ecological system , which is studied to gain a deeper understanding of the real system.Ecosystem models are formed by combining known ecological relations An ecosystem model is an abstract, usually mathematical,...

  • Ecosystem services
    Ecosystem services
    Humankind benefits from a multitude of resources and processes that are supplied by natural ecosystems. Collectively, these benefits are known as ecosystem services and include products like clean drinking water and processes such as the decomposition of wastes...

  • Ecosystem valuation
    Ecosystem valuation
    Ecosystem valuation is a widely used tool in determining the impact of human activities on an environmental system, by assigning an economic value to an ecosystem or its ecosystem services.-Value of ecosystem services:...

  • Ecotope
    Ecotope
    Ecotopes are the smallest ecologically-distinct landscape features in a landscape mapping and classification system. As such, they represent relatively homogeneous, spatially-explicit landscape functional units that are useful for stratifying landscapes into ecologically distinct features for the...

  • Edge effect
    Edge effect
    The edge effect in ecology is the effect of the juxtaposition or placing side by side of contrasting environments on an ecosystem.This term is commonly used in conjunction with the boundary between natural habitats, especially forests, and disturbed or developed land. Edge effects are especially...

  • Eugene Odum
    Eugene Odum
    Eugene Pleasants Odum was an American scientist known for his pioneering work on ecosystem ecology. He wrote the first ecology textbook: Fundamentals of Ecology....

  • Food chain
    Food chain
    A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...

  • Global warming
    Global warming
    Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

  • Invasive species
    Invasive species
    "Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....

  • Landscape ecology
    Landscape ecology
    Landscape ecology is the science of studying and improving relationships between urban development and ecological processes in the environment and particular ecosystems...

  • Leopold Report
    Leopold Report
    The Leopold Report, officially known as Wildlife Management in the National Parks, is a 1963 paper composed of a series of ecosystem management recommendations that were presented by the Special Advisory Board on Wildlife Management to United States Secretary of the Interior Stewart Udall. Named...

  • Natural environment
    Natural environment
    The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

  • Natural landscape
    Natural landscape
    A natural landscape is a landscape that is unaffected by human activity. A natural landscape is intact when all living and nonliving elements are free to move and change. The nonliving elements distinguish a natural landscape from a wilderness. A wilderness includes areas within which natural...

  • Natural resource
    Natural resource
    Natural resources occur naturally within environments that exist relatively undisturbed by mankind, in a natural form. A natural resource is often characterized by amounts of biodiversity and geodiversity existent in various ecosystems....

  • Nature
    Nature
    Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...

  • Push–pull technology
  • Software ecosystem
    Software ecosystem
    Software Ecosystem is a book written by David G. Messerschmitt and Clemens Szyperski that explains the essence and effects of a "Software Ecosystem", defined as a set of businesses functioning as a unit and interacting with a shared market for software and services, together with relationships...

  • Spaceship Earth
    Spaceship Earth
    Spaceship Earth is a world view term usually expressing concern over the use of limited resources available on Earth and the behavior of everyone on it to act as a harmonious crew working toward the greater good....

  • Sustainability
    Sustainability
    Sustainability is the capacity to endure. For humans, sustainability is the long-term maintenance of well being, which has environmental, economic, and social dimensions, and encompasses the concept of union, an interdependent relationship and mutual responsible position with all living and non...

  • Sustainable development
    Sustainable development
    Sustainable development is a pattern of resource use, that aims to meet human needs while preserving the environment so that these needs can be met not only in the present, but also for generations to come...



Further reading

  • Boer, P.J. den, and J. Reddingius. 1996. Regulation and stabilization paradigms in population ecology. Population and Community Biology Series 16. Chapman and Hall, New York. 397 pg.
  • Dame R., Olenin S. 2005. The Comparative Roles of Suspension-Feeders in Ecosystems. Springer. Dordrecht. 360 p.
  • Ecological Society of America, Ecosystem Services, 25 May 2007
  • Ehrlich, Paul; Walker, Brian “Rivets and Redundancy”.BioScience.vol.48.no.5. May 1998. pp. 387. American Institute of Biological Sciences.
  • Grime, J.P. "Biodiversity and Ecosystem Function: The Debate Deepens." Science Vol. 277. no. 533029 August 1997 pp. 1260–1261. 25 May 2007
  • Groom, Martha J., and Gary K. Meffe. Principles of Conservation Biology. 3. Sunderland, MA: Sinauer Associates, Inc, 2006.
  • Lawton, John H., What Do Species Do in Ecosystems?, Oikos, December, 1994. vol.71, no.3.
  • Lindeman, R.L. 1942. The trophic-dynamic aspect of ecology. Ecology '23: 399-418.
  • Patten, B.C. 1959. An Introduction to the Cybernetics of the Ecosystem: The Trophic-Dynamic Aspect. Ecology 40, no. 2.: 221-231.
  • Ranganathan, J and Irwin, F. (2007, May 7). Restoring Nature's Capital: An Action Agenda to Sustain Ecosystem Services
  • Vreugdenhil, D., Terborgh, J., Cleef, A.M., Sinitsyn, M., Boere, G.C., Archaga, V.L., Prins, H.H.T., 2003, Comprehensive Protected Areas System Composition and Monitoring, IUCN, Gland, Switzerland. 106 pg.

External links