Pinus cembroides subsp. lagunae (Rob.-Pass.) D.K.Bailey

Pinaceae

Endemic to Baja California in Mexico. This small popualtion is vulnerable to fire and grazing

Associated Names:

Distribution

Endemic to Mexico in Baja California Sur (Sierra de la Laguna). The population is restricted to a small area on the mountain where it does not occur in pure stands of any extent, but mixed mainly with oaks. The population size is estimated to be at least 1000 trees.

Habitat and Ecology

The Sierra de la Laguna is a batholitic uprising of granitic rock, flanked by older sedimentary rocks and rising to 2090m. Pinus cembroides subsp. lagunae occurs in the highest northern part of the range, at elevations between 1600 to 2050m. It is best developed on and around the high meadow (La Laguna) of sandy loam, but occurs also in valleys with coarse gravel or granite boulders, as well as on granitic slopes. It is commonly associated with Quercus devia, which is more abundant than Pinus in most areas. No other pines occur in Baja California Sur. On dry slopes Yucca, Calliandra and Dodonaea are found in the understorey. The climate is subtropical; annual precipitation in the area is ca. 750mm, almost all of which comes from summer rainstorms. Phenology: pollen dispersal occurs in May-June (Passini & Pinel, 1987).

Conservation Status

Global status

Vulnerable D2

Global rationale

The area of occupancy is calculated to be as little as 11km², based on herbarium specimens collected from 11 known localities. This may be an underestimate. These localities represent 2–3 locations with the total population size estimated to be more than 1000 trees, based on the field experience of this assessment's author. Although there is no current threat from logging or fires, this subspecies' susceptibility to stochastic events indicate an assessment of Vulnerable under the D2 criteria.

Global threats

There has been occasional but limited logging in the past. The mountain is difficult to access and there are no good roads for transport, only 4WD tracks. Grazing and fires are potential problems if they intensify or become more frequent than in the past.

Conservation Actions

The population occurs within a protected area and logging has stopped.