 thumb|right|250px|subtropical dry forest on vieques, puerto rico. the puerto rican dry forests are a subtropical dry forest ecoregion located in southwestern and eastern puerto rico and on the offshore islands.ewel, j.j. and whitmore, j.l. (1973) the ecological life zones of puerto rico and the u.s. virgin islands. usda forest service, institute of tropical forestry, rio piedras, puerto rico. they cover an area of . these forests grow in areas receiving less than  of rain annually. many of the trees are deciduous, losing their leaves during the dry season which normally lasts from december to july.murphy, p.g., lugo, a.e., murphy, a.j., nepstad, d.c. (1995) the dry forests of puerto rico's south coast. pp. 178-209 in a.e. lugo and c. lowe (editors) tropical forests: management and ecology. springer-verlag, new york. ==distribution== dry forests exist in two areas on the island of puerto rico - along the south coast of the island (in the dry orographic rain shadow of the cordillera central) and in the northeastern corner of the island near fajardo, where the combination of low elevation and strong winds off the ocean (northeast trade winds) result in a dry environment. dry forests also exist on the adjacent off-shore islands of vieques, culebra, mona, monito, desecheo, caja de muertos and cayo santiago. the vast majority of studies have focused on the south coast - almost nothing has been published about the northeastern dry forest. studies of the offshore islands have been limited to species lists and qualitative descriptions of the vegetation. ==ecology== puerto rican dry forests (like caribbean dry forests in general) consist of short-stature (usually < tall), multi-stemmed trees. the canopy is largely evergreen (dominated by gymnanthes lucida (euphorbiaceae) in areas of limestone soil), while the emergent layer is considerably more dry-season deciduous.lugo, a. e., j. a. gonzalez-liboy, b. cintrÃ³n, and k. dugger. (1978) structure, productivity and transpiration of a subtropical dry forest in puerto rico. biotropica 10:278-291.murphy, p. g., and a. e. lugo. (1986) structure and biomass of a subtropical dry forest in puerto rico. biotropica 18:89-96. guaiacum officinale, coccoloba venosa, ceiba pentandra, and capparis cynophallophora a
Ecoregions_of_the_Caribbean Flora_of_Puerto_Rico Forests_of_Puerto_Rico Neotropic_ecoregions Tropical_and_subtropical_dry_broadleaf_forests