The canopy is largely evergreen (dominated by Gymnanthes lucida in areas of limestone soil), while the emergent layer is considerably more dry-season deciduous.

[4] Puerto Rican dry forests are dominated by plants in the families Rubiaceae, Euphorbiaceae, and Myrtaceae.

[7] Guaiacum officinale, Coccoloba venosa, Ceiba pentandra, and Capparis cynophallophora are common trees in coastal dry forests.

Dry limestone forest species include Pisonia albida, Guaiacum sanctum, and Plumeria alba.

[2] Trichilia triacantha, a federally listed endangered species, is known only from the dry forest zone in southwestern Puerto Rico.

[13] Non-native mammals in the dry forest zone include rhesus macaques and patas monkeys, both of which have become serious agricultural pests,[14] and the Javan mongoose which was introduced to Puerto Rico in the 1870s.

[16] In addition, large areas of secondary forest have grown back on abandoned agricultural land.