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The Population and Community Ontology (PCO) describes material entities, qualities, and processes related to collections of interacting organisms such as populations and communities. It is taxon neutral, and can be used for any species, including humans. The classes in the PCO are useful for describing evolutionary processes, organismal interactions, and ecological experiments. Practical applications of the PCO include community health care, plant pathology, behavioral studies, sociology, and ecology.

The PCO is rooted in the Basic Formal Ontology (BFO). It is designed to be compatible with other OBO Foundry ontologies, such as the Gene Ontology (GO), which covers biological processes, and the Phenotype and Trait Ontology (PATO), which covers qualities.

Citing the PCO

If you use the ontology, please cite its IRI: Cite a specific version if that is more approporiate.

If you mention PCO in a paper, please cite one of the following:

Walls, R.L., Guralnick R.P., J. Deck, A. Buntzman, P.L. Buttigieg, N. Davies, M.W. Denslow, R.E. Gallery, J.J. Parnell, D. Osumi-Sutherland, R.J. Robbins, P. Rocca-Serra, J. Wieczorek, and J. Zheng. 2014. Meeting Report: Advancing Practical Applications of Biodiversity Ontologies. Standards in Genomic Sciences 9 (1): 17.

Walls, R.L., J. Deck, R.P. Guralnick, S. Baskauf, R. Beaman, S. Blum, S. Bowers, P.L. Buttigieg, N. Davies, D. Endresen, M.A. Gandolfo, R. Hanner, A. Janning, L. Krishtalka, A. Matsunaga, P. Midford, N. Morrison, É.Ó. Tuama, M. Schildhauer, B. Smith, B.J. Stucky, A. Thomer, J. Wieczorek, J. Whitacre, J. Wooley. 2014. Semantics in Support of Biodiversity Knowledge Discovery: An Introduction to the Biological Collections Ontology and Related Ontologies. PLoS ONE 2014, 9:e89606.

Contributing to PCO

Please use the issue tracker for comments, requests for new terms, and suggested changes to existing terms. Before submitting a new request, do a search to see if there is an existing issue on the same topic. Click the issues tab to reach the issue tracker.

If you are a PCO editor, please see the editors' readme file. External editors should fork the repo and make a branch to suggest changes.

You can send an email to the PCO mailing list at


An ontology about groups of interacting organisms such as populations and communities








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