Glossary¶
Key terms used across this site, defined in plain language.
Bioregion A geographic area defined by natural characteristics — watershed, climate, native plant communities, geology, and the web of species that evolved there — rather than by political or administrative boundaries. The word was coined in the early 1970s by writer Peter Berg and wildlife biologist Raymond Dasmann.
Bioregionalism The political and philosophical project of reorganizing human communities around ecological realities. Bioregionalism holds that human governance, economies, and cultures should be calibrated to the scale and carrying capacity of the places they inhabit.
Carrying Capacity The maximum population of a given species — including humans — that an ecosystem can sustain indefinitely without degrading the resource base. Exceeding carrying capacity depletes the system; living within it allows indefinite continuity.
Endemic Native to and found only in a specific place. An endemic species exists nowhere else on Earth. High rates of endemism in a region indicate long isolation and are a marker of exceptional conservation value.
Headwater The uppermost portion of a river system — the small streams and springs that feed larger rivers. Headwaters are disproportionately important ecologically: they are where many fish spawn, where the most sensitive species live, and where a watershed's overall health is set.
Hydrological Unit Code (HUC) The USGS numbering system for watersheds. A 2-digit HUC identifies a major river basin; a 12-digit HUC identifies a specific creek or stream reach. Every point in the contiguous United States has a HUC that tells you exactly which watershed it drains into.
Interbeing A term from Buddhist teacher Thich Nhat Hanh, adopted by many ecological thinkers, describing the fundamental interdependence of all phenomena — that nothing exists independently of everything else. In ecological terms: you are made of your watershed, your soil, your food web.
Karst A landscape formed by the dissolution of soluble rocks — primarily limestone — by slightly acidic water. Karst terrain features caves, sinkholes, disappearing streams, and springs. It produces some of the most biologically diverse and hydrologically complex landscapes on Earth. The Ozarks and much of the Appalachian plateau are karst.
Keystone Species A species whose ecological impact is disproportionately large relative to its abundance. Remove a keystone species and the entire ecosystem restructures. Classic examples: sea otters (whose removal allows sea urchins to overgraze kelp forests), prairie dogs (whose colonies support dozens of dependent species), and salmon (whose ocean nutrients feed entire river-valley ecosystems).
Mycorrhizal Network The web of fungal threads (hyphae) that connects the roots of trees and other plants in a forest, enabling the transfer of water, carbon, and nutrients between individual plants. Sometimes called the "wood wide web." Old-growth forests have the most complex and functional mycorrhizal networks.
Reinhabitation Peter Berg's term for the practice of learning to live in a place as if you intended to stay — developing ecological literacy, participating in local governance, orienting your economy and culture around the realities of your specific landscape. The opposite of treating a place as interchangeable.
Riparian Of or relating to riverbanks and streamside zones. Riparian vegetation — the trees, shrubs, and plants that grow along waterways — performs critical ecological functions: shading streams to keep water cool, stabilizing banks to prevent erosion, filtering agricultural runoff, and providing habitat corridors connecting otherwise isolated patches.
Sense of Place The felt relationship between a person or community and a specific location — the accumulated knowledge, memory, and identity that comes from deep familiarity with a particular land. A developed sense of place is the experiential foundation of bioregionalism.
Watershed All the land that drains into a common river, lake, or other body of water. A watershed is bounded by ridgelines — high points where rainfall splits to flow in opposite directions. Watersheds are the most natural unit of landscape governance because everything that happens on the land eventually shows up in the water.
Xeric / Mesic / Hydric Terms describing the moisture regime of a habitat. Xeric habitats are dry; mesic are moderately moist; hydric are wet or waterlogged. These gradients — often shifting across short distances on a hillside — determine which species can live where and are among the primary drivers of biodiversity at the landscape scale.