Living on the edge: composition, biogeography, and conservation of ferns in rocky environments of Southern Amazonia

We examined floristics, biogeography, and conservation status of ferns from rocky environments in Southern Amazonia. We collected specimens in four 1-ha plots, and considering the sampled species, we evaluated their phytogeographical and conservation attributes from online databases. We recorded 36 species and one subspecies distributed in 13 families and 21 genera. Pteridaceae and the genus Anemia (Anemiaceae) are characteristic of rocky environments and were the most representative taxa. In these environments, most of the species we documented were terrestrial. The sampled taxa have a wide distribution. Among the 35 taxa identified at the specific and subspecific level, two are classified as “Least Concern” and one as “Vulnerable.” In turn, 32 taxa do not have enough data to be included in any conservation category, and such taxa were evaluated by using the extent of occurrence (all classified as “Least Concern”) and the area of occupation (20 “Threatened” species and 12 “Vulnerable”). Such information about species that live on the edge, combined with a risk assessment, provides a range of attributes that can be used to make conservationist decisions.