The Puerto Rican dry forests are a tropical dry forest ecoregion located in southwestern and eastern Puerto Rico and on the offshore islands. 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 April. Geography The dry forest life zone 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 result in a dry environment. Dry forests also exist on the adjacent off-shore islands of Culebra, Mona, Monito, Desecheo, Caja de Muertos, Cayo Santiago and most of the island of Vieques. Dry forests along the south coast cover a strip of land from Guayama in the east to Cabo Rojo in the west, and extends inland from the coast. Climate The climate is seasonal with most rainfall between May and November. Average rainfall on the south coastal strip ranged from . 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 in areas of limestone soil), while the emergent layer is considerably more dry-season deciduous. Vegetation types Plant community types exist along a continuum of soil moisture availability, which is itself influenced by soil depth, and the orientation and the slope of the land (which affects runoff). Coastal vegetation includes mangrove, salt flats and beach thickets. Further inland, scrub forest grows on exposed limestone with scattered depressions. Deeper soils support deciduous forests with taller semi-evergreen forests growing on moister sites. The degree of deciduousness varies with water stress—drought–deciduous species retain more of their leaves in wetter years and lose more of them in drier years—and even in the deciduous forests, many trees are evergreen. Flora Puerto Rican dry forests are dominated by plants in the families Rubiaceae, Euphorbiaceae, and Myrtaceae. In this regard they are similar to Jamaican dry forests, but differ from dry forests on the mainland of South and Central America, which are dominated by Fabaceae and Bignoniaceae. Guaiacum officinale, Coccoloba venosa, Ceiba pentandra, and Capparis cynophallophora are common trees in coastal dry forests.