Wiktionary
n. The belief that naturally-defined regions (''bioregions'' or ''ecoregions'') should be the basis of political or cultural identity
Wikipedia
Bioregionalism is a political, cultural, and ecological system or set of views based on naturally defined areas called bioregions, similar to ecoregions. Bioregions are defined through physical and environmental features, including watershed boundaries and soil and terrain characteristics. Bioregionalism stresses that the determination of a bioregion is also a cultural phenomenon, and emphasizes local populations, knowledge, and solutions.
Bioregionalism is a concept that goes beyond national boundaries—an example is the concept of Cascadia, a region that is sometimes considered to consist of most of Oregon and Washington, the Alaska Panhandle, the far north of California and the West Coast of Canada, sometimes also including some or all of Idaho and western Montana. Another example of a bioregion, which does not cross national boundaries, but does overlap state lines, is the Ozarks, a bioregion also referred to as the Ozarks Plateau, which consists of southern Missouri, northwest Arkansas, the northeast corner of Oklahoma, southeast corner of Kansas.