As described in the team's paper in a recent issue of the scientific journal "Biodiversity and Conservation," the assessment consisted of two stages. An initial evaluation of the plant data determined that 1,476 species had ranges of more than 20,000 square kilometers and were classified as Not at Risk. Focusing on the remaining 549 species, the Garden scientists added more precise latitude and longitude references for the locations where many of the species samples had been collected. After recalculating their ranges, the team was able to determine that 90 additional species could be categorized as Not at Risk.
That means, however, that 459 species, or 23 percent of Puerto Rico's flora, should be considered At Risk. The analysis of more than 2,000 species took less than four months.
To test the method's reliability, the Garden scientists compared their results with the Red List, which has assessed only 77 species of Puerto Rican seed plants, assigning 53 to threatened categories. The Garden's rapid assessment process categorized 47 of the 53 species on the Red List as At Risk.
In addition to Dr. Miller, the Garden team consisted of Brian Boom, Ph.D., Director of the Garden's Caribbean Biodiversity Program; Holly A. Porter-Morgan, Ph.D.; Hannah Stevens; James Fleming; and Micah Gensler.
The "Biodiversity and Conservation" paper also describes a second rapid assessment method developed by the Smithsonian Institution, which categorized 367 species as At Risk. It overlapped with the Red List for 42 out of 53 species.
Beyond identifying a broad range of threatened species, the two methods could serve as valuable planning aids, the authors conclude. "The tools used to conduct these analyses can also map distributions of 'At Risk' species and identify specific geographic places where threatened plants are concentrated," they write.
|Contact: Stevenson Swanson|
The New York Botanical Garden