Pinus chiapensis (Martínez) Andresen

Pinaceae

Distributed in southern Mexico and Guatemala where it has been logged and forests have been converted for agricultural use. On the IUCN Redlist, this species is listed as a variety of Pinus strobus L.

Distribution

Mexico: in Guerrero, E Puebla, Veracruz, Oaxaca and Chiapas; Guatemala: in the departments of El Quiche and Huehuetenango. In Mexico it is most abundant in the States of Oaxaca and Chiapas; isolated occurrences are also found in Puebla, Guerrero, and Veracruz.

Subpopulations are generally small, 5 to 20ha throughout its range. The largest subpopulation at El Rincon in Oaxacana is estimated to have more than 50,000 mature individuals spread over an area of 1500ha of secondary forest (Castillo & Trujillo, 2008).

Habitat and Ecology

It occurs in the mountains of southern Mexico and Guatemala, at altitudes from 500m (but usually 800m) to 2200 metres above sea-level. It is usually found in mixed angiosperm-coniferous forest, or mixed with other pines in pine forests (less commonly). These are often cloud forests, with frequent fog, especially those ranges facing the Gulf of Mexico. Annual precipitation may exceed 3000mm. This variety experiences no frost. At low elevations it is associated with: Pinus maximinoi, P. oocarpa, P. devoniana, P. pringlei, at higher elevations with: Pinus ayacahuite, P. pseudostrobus, P. patula var. longipedunculata, P. tecunumanii and P. teocote. In wet places it also commonly occurs with Cyathaea mexicana (Dvorak et al., 2000). For a more detailed review of this variety’s ecology see Castillo et al., 2009.

Human Uses

Logging for its timber has been widespread, and although large trees are becoming rare in many locations, is still ongoing. Logs are used as beams in roofs of rural houses and buildings. The wood is used as firewood for cooking and for furniture manufacturing, and may be preferred over that of other coexisting pine species. The wood was a source of pulp for industrial papermaking in Oaxaca, before commercial exploitation was restricted. The resin is a fuel source, and is successfully applied to humans and domestic animals as an ointment in wounds and bone fractures (del Castillo & Acosta Castellanos, 2002). A resin extract is said to be helpful as an analgesic for rheumatic pain, and an inner bark infusion can be helpful against coughing (Castillo et al., 2009).

Conservation Status

Global status and rationale

Endangered B2ab(ii,iii,v)

Pinus chiapensis has a relatively large extent of occurrence. Within this area, subpopulations tend to small and isolated, with the largest subpopulations occurring in Chiapas and Oaxaca. The total area of occupancy, based on herbarium specimens representing all major localites, and using standard IUCN mapping techniques (IUCN 2011) is estimated to be 384km². Subpopulations are severely fragmented and there is a continuing decline in area of occupancy, quality of habitat and probably number of mature individuals. On this basis it is assessed as Endangered under the B2 criteria.

Global threats

Although a valuable timber tree logged locally, the main reason for its decline is deforestation and/or forest degradation. In some parts of its range it has historically been overexploited for ship building / repairs. The forest area originally occupied by P. chiapensis is being cut for growing corn, coffee plantations, or for establishing pastures for cattle, drastically reducing the subpopulations. An additional cause of destruction is the introduction of exotic species, such as Casuarina equisetifolia and Cupressus lusitanica in forests dominated by P. chiapensis. Levels of threat vary between regions and subpopulations.

Conservation Actions

Pinus chiapensis requires disturbance for regeneration. In a review of recent studies relating to its exploitation and conservation status it was identified as having been one of "the most abundant tree species in early successional stands of the tropical montane cloud forest playing a key role in ecosystem regeneration particularly in areas managed under slash-and-burn practices" (Castillo et al, 2009). Well preserved landscapes tended to have smaller populations as do areas that have been largely deforested. What is required to ensure its continued presence is a careful balance of forest preservation and forest utilisation.