The flora of Canon San Cristóbal, Puerto Rico.
Although it is one of the most spectacular geologic features in PR, the vegetation of Cañon de San Cristobal was seriously disturbed over the last century and a half by subsistence farming, grazing, and wood cutting. Now that agricultural activity has nearly ceased and the cayon is partially protected, the vegetation is rapidly recovering. At the request of the conservation trust of puerto rico, which owns about two thirds of the cayon, personnel of the U.S Deparment of Agriculture, Forest service, International Institute of Tropical Forestry, conducted a vegetation survey of the entire canyon. a total of 678 species were identified in the 1000-ha area including one new recording for Puerto Rico.