Biome: Tropical and Subtropical Dry Broadleaf Forests
Size: 500 square miles
Conservation Status: Critical/Endangered
G200: No

Introduction
Introduction
Tropical dry forests are located along the south-central and southwestern coast of Puerto Rico and on adjacent islands such as Mona, Vieques, Culebra, Desecheo, Caja de Muertos, and portions of each of the larger U.S. Virgin Islands (see Little & Wadsworth 1964, Dansereau 1966, Ewell & Whitmore 1973). The vegetation displays a range of adaptations to the several-month dry season and low annual rainfall (600 mm to 1000 mm on average), including deciduous leaves, waxy coatings on leaves, trunks, and branches, and water storage structures.

Description

Biological Distinctiveness 
Guaiacum officinale, Coccoloba venosa, Ceiba pentandra, Capparis cynophallophora are common trees of the coastal dry forests, while on the dry limestone forests species such as Pisonia albida, Guaiacum sanctum, and Plumeria alba are characteristic. The Puerto Rican nightjar (Caprimulgis noctitheris) is known only from a few areas in the dry southwest portion of the island (Raffaele 1989b), as are several snail species (van der Shalie 1948).

Conservation Status 
The last large block of coastal dry forest and dry limestone forest (ca. 40 km²) occurs within the Guçnica Commonwealth Forest and Biosphere Reserve. Tropical dry forests are highly threatened globally, particularly within the Greater and Lesser Antilles, making this reserve a high conservation priority. Clearing for development, fires, and introduced species continue to threaten the remaining dry forests.

Suite of Priority Activities to Enhance Biodiversity Conservation 

Conservation Partners

• Conservation Trust of Puerto Rico

Relationship to other classification schemes 
Puerto Rican dry forest boundaries were derived from the subtropical dry forest life zone of Ewell and Whitmore (1973).

Prepared by: D. Olson

This text was originally published in the book Terrestrial ecoregions of North America: a conservation assessment from Island Press. This assessment offers an in-depth analysis of the biodiversity and conservation status of North America's ecoregions.