Pinus occidentalis Sw.

Pinaceae

Once a widespread species on the Dominican Republic and Haiti where over time extensive logging has greatly reduced the population

Associated Names:

Hispaniolan pine

Distribution

Endemic to Hispaniola where it occurs in the Dominican Republic and Haiti.

Habitat and Ecology

This species occurs in diverse habitats from the lowlands at about 200m above sea-level to the highest mountain ridges (Pico Duarte and Pico La Pelona) on the island at almost 3200m. The more extensive and pure stands occur from 900–2700m, but in more accessible areas these are much depleted. Soils are either derived from limestone at lower altitudes, or more acid, clay-like and shallow in the Cordillera Central. Pinus occidentalis consequently is found in a variety of vegetation types, mostly occupying the shallow, nutrient-poor soils and rock outcrops, where it may occur in open or dense, pure stands or mixed with various broad-leaved trees and shrubs. In disturbed (grazed) areas Pteridium aquilinum can dominate the ground cover; in frequently burnt areas grasses (e.g. Danthonia domingensis, Andropogon spp.) and again Pteridium replace shrubs and small trees. Annual precipitation varies greatly with exposition, but ranges between 1200–1600mm where most pine forests occur, it exceeds 2300mm in the N and E of the Cordillera Central. There is a 3–5 month dry season during winter, which may bring frost, but rarely snow, at the higher altitudes above 1600–1800m.

Human Uses

This is an important timber tree in Hispaniola, where despite intensive exploitation it is still relatively common. Its wood has good qualities comparable to those found in the more widespread species P. caribaea and is used as round wood for transmission poles, fence posts, construction timber, crates, boxes, and made into wood pulp for particleboard as well as paper. There is limited resin tapping for local use only. It is a tropical pine and even those trees at the highest altitudes in the Dominican Republic are not likely to yield progeny that can be grown successfully in cool temperate climates.

Conservation Status

Global status

Endangered A2acd; B2ab(ii,iii,v)

Global rationale

On the basis of estimates of rates of exploitation given by Darrow & Zanoni (1991), a decline of at least 50% over the last three generations (100 years) is very plausible. As this decline has not ceased and the area of occupancy based on localities from comprehensive collecting of herbarium specimens (69 collections, 41 localities) and a grid width of 2km (appropriate fore a seriously depleted population) is well below the 500km² threshold, this species meets the criteria for Endangered.

Global threats

Being the only species of Pinus on Hispaniola and formerly abundant over much of the island, it has been heavily exploited for timber. According to Darrow & Zanoni (1991) it has been depleted from an estimated 3 million ha of primeval more or less pure pine forests to perhaps less than 5% of that area, but accurate estimates of even the present forest extent are lacking. Protection in the Dominican Republic is inadequate, but existent, contrary to the virtually uncontrolled situation in Haiti (Darrow & Zanoni, 1991).

Conservation Actions

It occurs in protected areas in Haiti (Macaya National Park) and in the Dominican Republic, but protection is poorly enforced. What is really needed is a stricter regulation of timber extraction to make it sustainable.