Madrean

Madrean is an adjective used in geography and biology to describe things related to the Madrean region, a biogeographic and floristic area of southwestern North America. The Madrean region spans parts of the southern United States and northern Mexico, and includes the Sierra Madre Occidental and Sierra Madre Oriental mountain systems and the deserts that lie between them. The term is commonly applied in studies of ecology, biogeography, and conservation to denote the natural history of this montane–desert landscape.

Geography and habitats within the Madrean region are shaped by strong elevational gradients. Low elevations are dominated by arid and semi-arid deserts, while higher elevations host diverse montane habitats such as oak–pine woodlands, pine-oak forests, and conifer forests, with cloud forests at the highest elevations. A notable feature associated with Madrean landscapes is the Madrean Sky Islands, a series of isolated mountain ranges that rise from desert basins, creating distinct ecological zones in close proximity.

Biodiversity and ecology in the Madrean region are characterized by high species richness and endemism, driven by the complex topography and climate variability. The combination of desert and montane habitats supports unique plant communities and a wide array of animal species, with many ecological interactions shaped by the vertical separation of sky islands.

Conservation and human context: Madrean habitats face pressures from land-use change, development, and climate change. Protected areas, national parks, and cross-border conservation initiatives aim to preserve oak–pine woodlands, conifer forests, and other Madrean ecosystems, while ongoing research documents their flora and fauna and informs management decisions. The term reflects a regional identity in natural history and cross-border ecological studies.