Encompassing Mexico's main mountain chains, and isolated mountaintop islands in Baja California and the southern United States, the Madrean Pine-Oak Woodlands is an area of rugged mountainous terrain, high relief, and deep canyons. A quarter of all Mexico's plant species are found here, many of them found nowhere else on Earth.
The pine forests of Michoacán provide famous overwintering sites for the annual migration of millions of monarch butterflies. Unfortunately, the destruction of pine forests due to excessive logging is the leading cause of habitat loss in this region.
†Recorded extinctions since 1500. *Categories I-IV afford higher levels of protection.
|Hotspot Original Extent (km² )
|Hotspot Vegetation Remaining (km²)
|Endemic Plant Species
|Endemic Threatened Birds
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|Area Protected (km²)
|Area Protected (km²) in Categories I-IV*
The Madrean Pine-Oak Woodlands Hotspot includes Mexico's main mountain chains, namely the Sierra Madre Occidental, the Sierra Madre Oriental, the Trans-Mexican Volcanic Belt, the Sierra Madre del Sur, and the Sierra Norte de Oaxaca, as well as isolated mountaintop islands in Baja California (particularly around the Sierra de la Laguna). Although the vast majority of the hotspot’s 461,265 km² lie within Mexico, a few scattered patches occur in the southern United States (represented by the Madrean Sky Islands, a series of about 40 mountain-tops in southern Arizona and New Mexico).
The complex geological history of the Madrean Pine-Oak Woodlands is evidenced by its rugged mountainous terrain, high relief, and deep canyons. The Trans-Mexican Volcanic Belt, which runs from west to east across central Mexico, and serves as a bridge connecting the Sierra Madre Occidental and the Sierra Madre Oriental, is the highest mountain chain in the hotspot, including the peaks of Pico de Orizaba (5,747 meters) and Popocatépetl (5,452 meters). The climate of the hotspot is primarily temperate, with annual precipitation varying between 500 and 2,500 millimeters, largely depending on slope and aspect.
Pine and oak forests are the characteristic vegetation type in the hotspot, ranging from monospecific stands of either pines (Pinus) or firs (Abies) to almost pure stands of oak (Quercus). In between these two extremes, different regions have varying combinations of species, with some more dominant than others. The pine-oak woodlands have an insular-type distribution by virtue of being surrounded by more extensive floristic provinces, generally tropical or arid. This feature is particularly noticeable in the northern Mexican Highlands and the Madrean Sky Island Archipelago.