The limestone region of Puerto Rico covers about 27.5 percent of the island’s surface and is subdivided into the northern, southern, and dispersed limestone areas. All limestone areas have karst features. The karst belt is that part of the northern limestone with the most spectacular surficial karst landforms. It covers 142,544 ha or 65 percent of the northern limestone. The karst belt is the focus of this publication, although reference is made to all limestone regions. The northern limestone contains Puerto Rico’s most extensive freshwater aquifer, largest continuous expanse of mature forest, and largest coastal wetland, estuary, and underground cave systems. The karst belt is extremely diverse, and its multiple landforms, concentrated in such a small area, make it unique in the world. Puerto Rico’s karst forests whether dry, moist, or wet share common physiognomic and structural characteristics. Karst forests contain the largest reported number of tree species per unit area in Puerto Rico. Both fauna and flora are rich in taxa; and many rare, threatened, endangered, and migratory species find refuge in the karst belt. Almost all fossil records of Puerto Rico’s extinct flora and fauna come from the karst belt.
Lugo, Ariel E.; Castro, Leopoldo Miranda; Vale, Abel; L pez, Tania del Mar; Prieto, Enrique Hern ndez; Martin , Andr s Garc a; Rol n, Alberto R. Puente; Tossas, Adrianne G.; McFarlane, Donald A.; Miller, Tom; Rodr guez, Armando; Lundberg, Joyce; Thomlinson, John; Col n, Jos ; Schellekens, Johannes H.; Ramos, Olga; Helmer, Eileen. 2001. Puerto Rican Karst-A Vital Resource. United States Department of Agriculture Forest Service Gen. Tech. Report WO-65