Sierra Madre del Sur pine–oak forests
The Sierra Madre del Sur pine–oak forests is a subtropical coniferous forest ecoregion in the Sierra Madre del Sur mountain range of southern Mexico.
Setting
The Sierra Madre del Sur pine–oak forests occupy an area of, within the states of Michoacán, Guerrero, and Oaxaca.The pine–oak forests occupy the higher slopes of the Sierra Madre del Sur range, which runs east and west parallel to Mexico's southern Pacific Coast. The forests are surrounded by tropical dry forests at lower elevations; the Jalisco dry forests to the west; the Balsas dry forests to the north, in the basin of the Balsas River, and the Southern Pacific dry forests to the south and east along the Pacific coast.
Flora
The chief plant communities are oak forests, cloud forests, pine–oak forests, and fir forests. The plant communities vary with elevation and rainfall.The oak forests occur between 1900 and 2500 metres elevation. Quercus magnoliifolia and Quercus castanea are the predominant tree species, with individuals of Pinus montezumae. Orchids and bromeliads grow as epiphytes.
Cloud forests grow at 2300 metres. Predominant tree species are Abies guatemalensis, Abies religiosa, Quercus uxoris, Pinus ayacahuite, and Cupressus lusitanica.
Pine–oak forests grow at 2400–2500 metres. Predominant tree species are Quercus magnoliifolia, Q. castanea, Q. obtusata, Pinus herrerae, P. pseudostrobus, P. pringlei, P. ayacahuite, P. rzedowskii, and Arbutus xalapensis.
Fir forests grow above 3,000 metres.
31 species of oaks are native to the ecoregion, including Q. mulleri, Q. nixoniana, Q. rubramenta, Q. salicifolia, Q. uxoris, and Q. martinezii.
The trees Aiouea cinnamomoidea, Magnolia guerrerensis, Magnolia krusei, Magnolia vazquezii, and Quercus mulleri are endemic to the ecoregion.