A pioneer organism, also called a disaster taxon, is an
organism
In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...
that populates a region after a (short-term) natural disaster, mass extinction, or any other event that kills off most life in that area.
Natural disaster
After a natural disaster, common pioneer organisms include
lichens and
algae.
Mosses usually follow lichens in colonization but cannot serve as pioneer organisms. These common pioneer organisms can have a preference in the temperatures they are in.
Lichens are more inclined to be in regions with more rainfall, whereas
algae and
mosses have a preference of being in regions with more humidity.
Pioneer organisms modify their environment and establish conditions that accommodate other organisms. In some circumstances, other organisms can be considered pioneer organisms. Birds are usually the first to inhabit newly-created islands, and seeds, such as the
coconut, may also be the first arrivals on barren soil.
Extinction event
Since the resolution of the fossil record is low, pioneer organisms are often identified as those that lived within hundreds, thousands, or a million years of the extinction event. For example, after the
Permian–Triassic extinction event
The Permian–Triassic (P–T, P–Tr) extinction event, also known as the Latest Permian extinction event, the End-Permian Extinction and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, as ...
252 million years ago, ''
Lystrosaurus
''Lystrosaurus'' (; 'shovel lizard'; proper Greek is λίστρον ''lístron'' ‘tool for leveling or smoothing, shovel, spade, hoe’) is an extinct genus of herbivorous dicynodont therapsids from the late Permian and Early Triassic epochs ( ...
'', a tusked
therapsid
Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...
, was considered a disaster taxon.
See also
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Ecological succession
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Primary succession
Primary succession is the beginning step of ecological succession after an extreme disturbance, which usually occurs in an environment devoid of vegetation and other organisms. These environments are typically lacking in soil, as disturbances l ...
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Secondary succession
Secondary succession is the secondary ecological succession of a plant's life. As opposed to the first, primary succession, secondary succession is a process started by an event (e.g. forest fire, harvesting, hurricane, etc.) that reduces an a ...
References
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Ecological succession
Population ecology