Pioneer organism
A pioneer organism, also called a disaster taxon, is an organism that populates a region after a (short-term) natural disaster, mass extinction, or any other event that kills off most life in that area.[1]
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.[2]
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 252 million years ago, Lystrosaurus, a tusked therapsid, was considered a disaster taxon.[1]
References
- Sahney, S. & Benton, M.J. (2008). "Recovery from the most profound mass extinction of all time". Proceedings of the Royal Society B: Biological Sciences. 275 (1636): 759–65. doi:10.1098/rspb.2007.1370. PMC 2596898. PMID 18198148.
- Jackson, Togwell (January 1971). "Study of the ecology of pioneer lichens, mosses, and algae on recent Hawaiian lava flows". Vol. 25.