Puerto Rico is the only location within the United States, other than Hawaii, where tropical rain forest ecosystems are available for scientific inquiry. A rich research tradition on the island extends back to the turn of the early 1900s. Most of this research has been concentrated in the Luquillo Experimental Forest, a Biosphere Reserve that coincides with the boundaries of El Yunque National Forest in the Luquillo Mountains. Within the LEF, El Verde Field Station, situated at 350 m elevation on the northwestern slope of the mountains, has been an important research location for tropical ecology since 1962.

In 1988 the National Science Foundation established the Luquillo Long-Term Ecological Research (Luquillo-LTER), and El Verde became the principal site for research in the program. Currently, the Environmental Sciences Department,  University of Puerto Rico, Rio Piedras Campus (UPR-RP), administers the station and surrounding research area under an agreement with USDA Forest Service. The station is used by numerous faculty, post-docs, and graduate and undergraduate students from the University of Puerto Rico, USDA Forest Service, and other academic institutions in Puerto Rico, mainland United States, and other countries.