An indicator species is any biological species that defines a trait or characteristic

Characteristic

Characteristic may refer to:In physics and engineering, any characteristic curve that shows the relationship between certain input and output parameters, for example:...

 of the environment. For example, a species may delineate an 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...

 or indicate an environmental condition

Environmental science

Environmental science is an interdisciplinary academic field that integrates physical and biological sciences, to the study of the environment, and the solution of environmental problems...

 such as a disease

Disease

A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

 outbreak, pollution

Pollution

Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...

, species competition or 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...

 change. Indicator species can be among the most sensitive species in a region, and sometimes act as an early warning to monitoring biologists.

Definitions

Lindenmayer et al. suggest 7 alternative definitions of indicator species:

1. a species whose presence indicates the presence of a set of other species and whose absence indicates the lack of that entire set of species;
2. a keystone species
   Keystone species
   A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Such species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and...
   
   , which is a species whose addition to or loss from an ecosystem leads to major changes in abundance or occurrence of at least one other species
3. a species whose presence indicates human-created abiotic conditions such as air or water pollution (often called a pollution indicator species)
4. a dominant species
   Dominant species
   Dominant species may mean:*Dominant species , one of a small number of species which dominate in an ecological community*Dominant Species by Michael E. Marks*Dominant Species...
   
    that provides much of the biomass
   Biomass (ecology)
   Biomass, in ecology, is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms,...
   
    or number of individuals in an area
5. a species that indicates particular environmental conditions such as certain 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...
   
    or rock types
6. a species thought to be sensitive to and therefore to serve as an early warning indicator of environmental changes such as global warming or modified fire regimes (sometimes called a bioindicator species)
7. a management indicator species, which is a species that reflects the effects of a disturbance regime or the efficacy of efforts to mitigate disturbance effects.

Type 1, 2, and 4 have been proposed as indicators of biological diversity and types 3, 5, 6, and 7 as indicators of abiotic conditions and/or changes in ecological processes.

Indicator Species for Ancient Woodland in England

Indicator species for ancient woodland in England need to be shade tolerant and slow colonisers. Plant species include Common wood sorrel

Common wood sorrel

Common Wood-sorrel is a plant from the genus Oxalis, common in most of Europe and parts of Asia. The binomial name is Oxalis acetosella, because of its sour taste. In much of its range it is the only member of its genus and hence simply known as "the" wood-sorrel...

, Wood Anemone

Anemone nemorosa

Anemone nemorosa is an early-spring flowering plant in the genus Anemone in the family Ranunculaceae, native to Europe. Common names include wood anemone, windflower, thimbleweed and smell fox, an allusion to the musky smell of the leaves...

, Wild Daffodil

Narcissus pseudonarcissus

Narcissus pseudonarcissus is a perennial flowering plant which grows from a bulb. It has pale yellow flowers with a darker central trumpet...

, Golden Saxifrage

Chrysosplenium

Chrysosplenium is a genus of 57 species of flowering plants in the family Saxifragaceae...

, Wild Garlic

Ramsons

Ramsons — also known as buckrams, wild garlic, broad-leaved garlic, wood garlic, bear leek, and bear's garlic — is a wild relative of chives native to Europe and Asia...

 and in the East of England

East of England

The East of England is one of the nine official regions of England. It was created in 1994 and was adopted for statistics from 1999. It includes the ceremonial counties of Essex, Hertfordshire, Bedfordshire, Cambridgeshire, Norfolk and Suffolk. Essex has the highest population in the region.Its...

 and Lincolnshire

Lincolnshire

Lincolnshire is a county in the east of England. It borders Norfolk to the south east, Cambridgeshire to the south, Rutland to the south west, Leicestershire and Nottinghamshire to the west, South Yorkshire to the north west, and the East Riding of Yorkshire to the north. It also borders...

, Common Bluebell

Common Bluebell

Hyacinthoides non-scripta, commonly known as the common bluebell, is a spring-flowering bulbous perennial plant. -Taxonomy:...

s.

See also

• Animal sentinels
  Animal sentinels
  There is increasing recognition that wild, domestic, and companion animals may act as "sentinels" for environmental health hazards by providing early warning of human health hazards in the environment...
  
  
• Bioindicator
  Bioindicator
  Biological indicators are species used to monitor the health of an environment or ecosystem. They are any biological species or group of species whose function, population, or status can be used to determine ecosystem or environmental integrity. An example of such a group are the copepods and other...
  
  
• Biological integrity
  Biological integrity
  Biological integrity is associated with how “pristine” an environment is and its function relative to the potential or original state of an ecosystem before human alterations were imposed. Biological integrity is built on the assumption that a decline in the values of an ecosystem's functions are...
  
  
• Botanical prospecting for uranium
  Botanical prospecting for uranium
  Botanical prospecting for uranium is a method of finding uranium deposits either by observation of plant life growing on the surface, or by geochemical analysis of plant material....
  
  
• Ecological indicator
  Ecological indicator
  Ecological indicators are used to communicate information about ecosystems and the impact human activity has on ecosystems to groups such as the public or government policy makers. Ecosystems are complex and ecological indicators can help describe them in simpler terms that can be understood and...
  
  
• Environmental indicator
  Environmental indicator
  Environmental indicators are simple measures that tell us what is happening in the environment. Since the environment is very complex, indicators provide a more practical and economical way to track the state of the environment than if we attempted to record every possible variable in the environment...
  
  
• Indicator plant
  Indicator plant
  - Definition :Since a plant species or plant community acts as a measure of environmental conditions, it is referred to as biological indicators/bioindicators/phytoindicators...
  
  
• Indicator value
  Indicator value
  Ellenberg's indicator values are simple ordinal classes of organisms with a similar realized ecological niche along a gradient. The latest edition of Ellenberg's indicator values contain values on a 9 point scale for soil acidity, productivity/nutrients, soil humidity, continentality, soil salt...
  
  

External links

• Indicator Plant/Indicator Animal species marietta.edu—"The Tropical Rain Forest"
• Biological Indicators of Watershed Health: Biological Integrity - US Environmental Protection Agency
• Canary Database: Index