Bromeliad species of the Atlantic forest of north-east Brazil: losses of critical populations of endemic species

Abstract

In this paper we examine the number of known populations of 86 bromeliad species recorded in the Atlantic forest of north-east Brazil, to test the following predictions: (1) the current number of populations of most bromeliad species inhabiting the Atlantic forest of north-east Brazil is critically low, (2) the number of extant populations of a particular species is associated with the ecological attributes of the species, and (3) habitat loss determines, at least in part, the current distribution and number of populations of each species. At present there are at least 535 bromeliad populations in this forest but 61.6% of species have <6 populations and 24.4% have only one known population. The mean number of populations per species was significantly lower among species endemic to this part of the Atlantic forest, species recorded in only one vegetation type, forest and inselberg species, and obligatory epiphytic and terrestrial species. We were unable to relocate 41 populations recorded between 1920 and 1996, and populations of 20 species have become locally extinct. For these bromeliads geographic range, habitat specificity and life form appear to determine which species are more vulnerable to extinction. The species that have <6 extant populations include 27 species that are endemic to this forest. These species need to be evaluated for inclusion on both the IUCN and Brazilian Red Lists. Some of these species will only survive if the fragments containing the last populations are declared as protected areas.