Filling the gap to avoid extinction: Conservation status of Brazilian species of Epidendrum L. (Orchidaceae)

Abstract

Orchidaceae has the largest percentage of threatened genera and species in relation to other plant families. One of the largest neotropical genus in this family is Epidendrum, represented in Brazil by 130 species. In this study, we assessed the conservation status of 63 Brazilian endemic species of Epidendrum. We characterized the extinction risk following the International Union for Conservation of Nature (IUCN) assessment guide, using criterion B. We considered species with a minimum number of four samples with confirmed occurrence localities and we measured the decline in quality or absolute reduction in the geographical distribution area of the species due to vegetation suppression (conditions bi, bii and biii of criterion B) in the last 35 years, using data available in MAPBIOMAS. A total of 2,754 records belonging to 37 assessed species were gathered, other 24 species were classified as Data Deficient (DD), and two were not assessed. Among the assessed species, 10 were categorized as Endangered (EN), six as Vulnerable (VU), 10 as Near Threatened (NT) and 11 as Least Concern (LC). The results reveal that epiphytic species of the Atlantic Forest were more frequently assessed in some degree of threat (55%). E. strobilicaule Hágsater & Benelli had the largest reduction of distribution area in the last 35 years to the classes of human use that include economical activities, while E. paniculosum Barb.Rodr. showed the smallest reduction. The main threats of the last 35 years for the analyzed species were conversion of land to pastures, urbanization, and the conversion of land to a mosaic of agriculture and pasture. This study provides important information about the conservation status of Brazilian endemic species of Epidendrum, helping to fill an expressive gap of non-assessed species.