Editing Ecoregion (section)

==History==
The history of the term is somewhat vague. It has been used in many contexts: forest classifications (Loucks, 1962), [[biome]] classifications (Bailey, 1976, 2014), [[biogeography|biogeographic]] classifications ([[World Wildlife Fund|WWF]]/[[Global 200]] scheme of Olson & Dinerstein, 1998), etc.<ref>Loucks, O. L. (1962). A forest classification for the Maritime Provinces. ''Proceedings of the Nova Scotian Institute of Science'', 25(Part 2), 85–167.</ref><ref name="Bailey, R. G 1976">Bailey, R. G. 1976. ''Ecoregions of the United States'' (map). Ogden, Utah: USDA Forest Service, Intermountain Region. 1:7,500,000.</ref><ref>Bailey, R. G. 2002. ''Ecoregion-based design for sustainability''. New York: Springer, [https://books.google.com/books?id=mDrhBwAAQBAJ].</ref><ref name="fnG8BAAAQBAJ2">Bailey, R. G. 2014. ''Ecoregions: The Ecosystem Geography of the. Oceans and Continents''. 2nd ed., Springer, 180 pp., [https://books.google.com/books?id=fnG8BAAAQBAJ].</ref><ref>Olson, D. M. & E. Dinerstein (1998). The Global 200: A representation approach to conserving the Earth's most biologically valuable ecoregions. ''Conservation Biol.'' 12:502–515.</ref>

The phrase "ecological region" was widely used throughout the 20th century by biologists and zoologists to define specific geographic areas in research. In the early 1970s, the term 'ecoregion' was introduced (short for ecological region), and R.G. Bailey published the first comprehensive map of U.S. ecoregions in 1976.<ref name="Bailey, R. G 1976"/> The term was used widely in scholarly literature in the 1980s and 1990s, and in 2001 scientists at the U.S. conservation organization World Wildlife Fund (WWF) codified and published the first global-scale map of Terrestrial Ecoregions of the World (TEOW), led by D. Olsen, E. Dinerstein, E. Wikramanayake, and N. Burgess.<ref>{{Cite journal |last=David M. Olson, Eric Dinerstein, Eric D. Wikramanayake, Neil D. Burgess, George V. N. Powell, Emma C. Underwood, Jennifer A. D'amico, Illanga Itoua, Holly E. Strand, John C. Morrison, Colby J. Loucks, Thomas F. Allnutt, Taylor H. Ricketts, Yumiko Kura, John F. Lamoreux, Wesley W. Wettengel, Prashant Hedao, Kenneth R. Kassem |date=November 1, 2001 |title=Terrestrial Ecoregions of the World: A New Map of Life on Earth |url=https://academic.oup.com/bioscience/article/51/11/933/227116 |journal=BioScience |volume=51 |issue=11 |via=Oxford Academic}}</ref> While the two approaches are related, the Bailey ecoregions (nested in four levels) give more importance to ecological criteria and climate zones, while the WWF ecoregions give more importance to biogeography, that is, the [[Species distribution|distribution]] of distinct species assemblages.<ref name="fnG8BAAAQBAJ2"/>

The TEOW framework originally delineated 867 terrestrial ecoregions nested into 14 major biomes, contained with the world's 8 major biogeographical realms. Subsequent regional papers by the co-authors covering Africa, Indo-Pacific, and Latin America differentiate between ecoregions and bioregions, referring to the latter as "geographic clusters of ecoregions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)",<ref name=":3">Burgess, N.D.; D'Amico Hales, J.; Dinerstein, E.; et al. (2004). ''Terrestrial eco-regions of Africa and Madagascar: A conservation assessment''. Washington DC.: Island Press [https://www.researchgate.net/publication/292588815_Terrestrial_eco-regions_of_africa_and_Madagascar_A_conservation_assessment]</ref><ref name="teip">Wikramanayake, Eric; Eric Dinerstein; Colby J. Loucks; et al. (2002). ''Terrestrial Ecoregions of the Indo-Pacific: a Conservation Assessment.'' Washington, DC: Island Press</ref><ref name=":4">Dinerstein, E., Olson, D. Graham, D.J. et al. (1995). ''A Conservation Assessment of the Terrestrial Ecoregions of Latin America and the Caribbean.'' World Bank, Washington DC., [http://documents.worldbank.org/curated/en/957541468270313045/pdf/multi-page.pdf].</ref> though the Assessment by Graham defines a bioregion exclusively in the sense of biogeographic history.<ref> name=":4">Dinerstein, E., Olson, D. Graham, D.J. et al. (1995). ''A Conservation Assessment of the Terrestrial Ecoregions of Latin America and the Caribbean.'' World Bank, Washington DC., [http://documents.worldbank.org/curated/en/957541468270313045/pdf/multi-page.pdf]. |quote= A bioregion is a geographically related assemblage of ecoregions that share a similar biogeographic history…</ref> The specific goal of the authors was to support global biodiversity conservation by providing a "fourfold increase in resolution over that of the 198 biotic provinces of Dasmann (1974) and the 193 units of Udvardy (1975)." In 2007, a comparable set of Marine Ecoregions of the World (MEOW) was published, led by M. Spalding,<ref>{{Cite journal |last=Mark D. Spalding, Helen E. Fox, Gerald R. Allen, Nick Davidson, Zach A. Ferdaña, Max Finlayson, Benjamin S. Halpern, Miguel A. Jorge, Al Lombana, Sara A. Lourie, Kirsten D. Martin, Edmund McManus, Jennifer Molnar, Cheri A. Recchia, James Robertson |date=July 1, 2007 |title=Marine Ecoregions of the World: A Bioregionalization of Coastal and Shelf Areas |url=https://academic.oup.com/bioscience/article/57/7/573/238419 |journal=BioScience |volume=57 |issue=7 |via=Oxford Academic}}</ref> and in 2008 a set of Freshwater Ecoregions of the World (FEOW) was published, led by R. Abell.<ref>{{Cite journal |last=Robin Abell, Michele L. Thieme, Carmen Revenga, Mark Bryer, Maurice Kottelat, Nina Bogutskaya, Brian Coad, Nick Mandrak, Salvador Contreras Balderas, William Bussing, Melanie L. J. Stiassny, Paul Skelton, Gerald R. Allen, Peter Unmack, Alexander Naseka, Rebecca Ng, Nikolai Sindorf, James Robertson, Eric Armijo, Jonathan V. Higgins, Thomas J. Heibel, Eric Wikramanayake, David Olson, Hugo L. López, Roberto E. Reis, John G. Lundberg, Mark H. Sabaj Pérez, Paulo Petry |date=May 1, 2008 |title=Freshwater Ecoregions of the World: A New Map of Biogeographic Units for Freshwater Biodiversity Conservation |url=https://doi.org/10.1641/B580507 |journal=BioScience |volume=58 |issue=5 |pages=403–414 |doi=10.1641/B580507 |via=Oxford Academic}}</ref>

Bailey's ecoregion concept prioritizes ecological criteria and climate, while the WWF concept prioritizes biogeography, that is, the [[Species distribution|distribution]] of distinct species assemblages.<ref name="fnG8BAAAQBAJ2"/>

In 2017, an updated terrestrial ecoregions dataset was released in the paper "An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm" led by E. Dinerstein with 48 co-authors.<ref>{{Cite journal |last=Dinerstein |first=Eric |date=5 April 2017 |title=An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm |url=https://academic.oup.com/bioscience/article/67/6/534/3102935 |journal=BioScience |volume=67 |issue=6 |pages=534–545 |doi=10.1093/biosci/bix014 |pmid=28608869 |pmc=5451287 |via=Oxford Academic}}</ref> Using recent advances in satellite imagery the ecoregion perimeters were refined and the total number reduced to 846 (and later 844), which can be explored on a web application developed by Resolve and Google Earth Engine.<ref>{{Cite web |last=Dinerstein (Ed.) |first=Eric |date=2017 |title=Ecoregions 2017 |url=https://ecoregions.appspot.com/ |website=Ecoregions 2017}}</ref>