A bioregion is a geographical area, on land or at sea, defined not by administrative boundaries but by distinct characteristics such as plant and animal species, ecological systems, soils and landforms, human settlements and cultures those attributes give rise to, and topographic features such as watersheds.[1][2][3][4][5][6][7][8] The term is used within the research fields of Biology, Ecology, Biogeography, and Biocultural Anthropology. It was also adopted and popularized in the mid-1970s by a school of philosophy called Bioregionalism, which includes the concept that human culture, in practice, can influence bioregional definitions.[9] Bioregions are part of a nested series of ecological scales, generally starting with local watersheds, growing into larger river systems, then Level III or IV Ecoregions (or regional ecosystems), bioregions, then biogeographical Realm, followed by the continental-scale and ultimately the biosphere.[10][11]
Within the life sciences, there are numerous methods used to define the physical limits of a bioregion based on the spatial extent of mapped ecological phenomena -- from Species Distributions and hydrological systems (i.e. Watersheds) to topographic features (e.g. Landforms) and climate zones (e.g. Köppen Classification). Bioregions also provide an effective framework in the field of Environmental history, which seeks to use "river systems, ecozones, or mountain ranges as the basis for understanding the place of human history within a clearly delineated environmental context"[12]. A bioregion can also have a distinct cultural identity[13][14] defined, for example, by Indigenous Peoples whose historical, mythological and biocultural connections to their lands and waters shape an understanding of place and territorial extent.[15] Within the context of bioregionalism, bioregions can be socially constructed by modern-day communities for the purposes of better understanding a place "... with the aim to live in that place sustainably and respectfully."[16]
Bioregions have practical applications in the study of Biocultural Anthropology, Bioregionalism, Biodiversity, Bioeconomics, Bioregional Financing Facilities, Bioregional Mapping, Community Health, Conservation Biology, Environmental history, Environmental science, Foodsheds, Geography, Natural Resource Management, Urban Ecology, Urban Planning.[17][18] References to the term "bioregion" in scholarly literature have grown exponentially since the introduction of the term -- from a single research paper in 1971 to approximately 65,000 journal articles and books published to date.[19] Governments and multilateral institutions have utilized bioregions in mapping Ecosystem Services and tracking progress towards conservation objectives, such as ecosystem representation.[20]
For conservation practitioners and organizations monitoring progress towards the goals of the United Nations Convention on Biological Diversity (CBD), in particular the goal of ecosystem representation in Protected Area networks, the most widely used bioregional delineations include the Resolve Ecoregions and the IUCN Global Ecosystem Typology.