Abundance (ecology)

Abundance is an ecological

Ecology

Ecology is the interdisciplinary scientific study of the interactions between organisms and the interactions of these organisms with their environment....

 concept referring to the relative representation of a species in a particular ecosystem

Ecosystem

An ecosystem is a system of interdependent organisms which share the same habitat, in an area functioning together with all of the physical factors of the environment. Ecosystems can be permanent or temporary. Ecosystems usually form a number of food webs...

. It is usually measured as the large number of individuals found per sample. How species abundances are distributed within an ecosystem is referred to as relative species abundance

Relative species abundance

Relative species abundance is a component of biodiversity and refers to how common or rare a species is relative to other species in a defined location or community...

s.

Abundance is contrasted with, but typically correlates to, incidence

Incidence

Incidence may refer to:* Incidence , a measure of the risk of developing some new condition within a specified period of time* Incidence , the binary relations describing how subsets meet...

, which is the frequency with which the species occurs at all in a sample.

Abundance is an ecological

Ecology

Ecology is the interdisciplinary scientific study of the interactions between organisms and the interactions of these organisms with their environment....

 concept referring to the relative representation of a species in a particular ecosystem

Ecosystem

An ecosystem is a system of interdependent organisms which share the same habitat, in an area functioning together with all of the physical factors of the environment. Ecosystems can be permanent or temporary. Ecosystems usually form a number of food webs...

. It is usually measured as the large number of individuals found per sample. How species abundances are distributed within an ecosystem is referred to as relative species abundance

Relative species abundance

Relative species abundance is a component of biodiversity and refers to how common or rare a species is relative to other species in a defined location or community...

s.

Abundance is contrasted with, but typically correlates to, incidence

Incidence

Incidence may refer to:* Incidence , a measure of the risk of developing some new condition within a specified period of time* Incidence , the binary relations describing how subsets meet...

, which is the frequency with which the species occurs at all in a sample. When high abundance is accompanied by low incidence, it is considered locally or sporadically abundant.

A variety of sampling methods are used to measure abundance. For larger animals, these may include spotlight

Spotlight

Spotlight can refer to several types of lighting:* a searchlight* a Followspot, a light used in theatre* several types of stage lighting instrumentIn the media, Spotlight can refer to:* Spotlight , a defunct premium movie channel...

 counts, track counts and roadkill

Roadkill

Roadkill is an animal or animals that have been struck and killed by motor vehicles. Mammals are the animals most likely to be recorded as roadkill...

 counts, as well as presence at monitoring stations.

Relative species abundance is calculated by dividing the number of species from one group by the total number of species from all groups.

See also

• Living Planet Index
  Living Planet Index
  The Living Planet Index is an indicator of the state of global biological diversity, based on trends in vertebrate populations of species from around the world....
  
  
• Occupancy-abundance relationship
  Occupancy-abundance relationship
  In macroecology, the occupancy-abundance relationship describes the relationship between the abundance of species and the size of their ranges within a region. This relationship is perhaps one of the most well-documented relationships in macroecology, and applies both intra- and interspecifically...
  
  
• Range (biology)
  Range (biology)
  In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
  
  
• Species richness
  Species richness
  Species richness is the number of different species in a given area. It is represented in equation form as .Typically, species richness is used in conservation studies to determine the sensitivity of ecosystems and their resident species. The actual number of species calculated alone is largely an...