Sierra de la Laguna pine–oak forests

The Sierra de la Laguna pine–oak forests are a subtropical coniferous forest ecoregion, found in the Sierra de la Laguna mountain range at the southern tip of the Baja California Peninsula, Mexico.

It is found within Los Cabos Municipality and eastern La Paz Municipality of southern Baja California Sur state.

Setting
The ecoregion encompasses an area of 1100 km2. The pine–oak forests are found above 800 m in elevation, and are surrounded at lower elevations by the Sierra de la Laguna dry forests. The pine–oak forests have a unique and diverse flora and fauna, including 694 plant species, of which approximately 85 are endemic.

Climate
The higher elevation gives the ecoregion a subtropical to temperate climate, in contrast to the dry tropical climate of the lowlands. Rainfall is higher than the lower-elevation dry forests and deserts of the peninsula, averaging 760 mm annually. Rain falls mostly in the summer, with occasional winter rains.

Flora
The composition of the pine–oak forests varies with elevation; oak woodlands predominate from 800 - 1200 m in elevation, with oak-pine woodlands between 1200 - 1600 m in elevation, transitioning to pine–oak forests above 1600 m in elevation. Mosses and lichens are abundant throughout.

The oak woodlands from 800 - 1200 m in elevation are warmer and drier, with evergreen oaks predominant (principally Quercus devia; Quercus arizonica and Quercus rugosa have a limited distribution), along with lower trees and shrubs such as Dodonaea viscosa, Sideroxylon peninsulare, and Buddleia crotonoides.

Above 1200 m in elevation, the oak woodlands transition to oak-pine forests. The only pine present is an endemic subspecies of Mexican Pinyon, Pinus cembroides subsp. lagunae, mixed with oaks, including Quercus devia and Quercus tuberculata, and other broadleaf trees, including Arbutus peninsularis and Nolina beldingii. Lower trees and understory shrubs include Calliandra peninsularis, Mimosa xanti, Heterotoma aurita, Verbesina pustulata and Hypericum peninsulare. Above 1600 m in elevation, pine predominates, mixed with oaks, and with an understory of grasses (Muhlenbergia spp. and Festuca spp.).

Fauna
30 mammal species, 77 birds, 27 reptiles, 2 amphibians, and 108 species of arthropods inhabit the ecoregion.

Larger mammals include mule deer (Odocoileus hemionus), puma (Puma concolor), coyote (canis latrans), gray fox (Urocyon cinereoargenteus), bobcat (Lynx rufus), raccoon (Procyon lotor), ringtail (Bassariscus astutus), and western spotted skunk (Spilogale gracilis).

Resident birds include the cape pygmy owl (Glaucidium hoskinsii), white-winged dove (Zenaida asiatica), acorn woodpecker (Melanerpes formicivorus), and golden eagle (Aquila chrysaetos). Xantus's hummingbird (Basilinna xantusii) and the peninsular yellowthroat (Geothlypis beldingi) are endemic to the southern Baja California Peninsula.

Conservation and threats
WWF has designated the ecoregion as 'vulnerable'.

A 2017 assessment found that 670 km2, or 63%, of the ecoregion is in protected areas.

In 2003, UNESCO designated a portion of the Sierra de la Laguna as a biosphere reserve. The reserve covers an area of 112,522 ha, of which 32,519 ha is designated the core area, centered on the pine-oak forests. A larger buffer area (80,003 ha) also includes lower-elevation dry forests and shrublands. The reserve is administered by Mexico's Comisión Nacional de Áreas Naturales Protegidas (CONANP).