A pioneer organism is an 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...

 that populates a region after a natural disaster or any other event that may have caused most life in that area to disappear. Common pioneer organisms include lichen

Lichen

Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...

s and algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

. Mosses usually follow lichens in colonization, but cannot serve as pioneer organisms. Pioneer organisms modify their environment and establish conditions under which more advanced organisms can live. 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

Coconut

The coconut palm, Cocos nucifera, is a member of the family Arecaceae . It is the only accepted species in the genus Cocos. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word...

, may also be the first arrivals on barren soil.