Mapping threats to the orchid populations in an environmental protection area in Bahia, northeast Brazil

Abstract

The área de proteção ambiental das Lagoas e Dunas do Abaeté (APA Abaeté) is an environmentally protected restinga fragment located in an urban area in the municipality of Salvador, the third most populous municipality in Brazil. We presented an updated list of Orchidaceae in APA Abaeté, including data on population size, aiming to support effective conservation strategies for orchids in Atlantic Forest remnants in the state. We carried out intensive fieldwork during October 2014 and February 2018, and analyzed several collections from Brazilian herbaria. Photographs, maps, short taxonomic notes and ecological information of the species are provided. We divided APA Abaeté into 16 plots (each with about 1.9 km2) to facilitate the discussion regarding local conservation actions. We found 15 genera and 19 species, including highly ornamental orchids (e.g. Brassavola tuberculata and Encyclia dichroma). Most species are terricolous and occur in the restinga forest formation (68%). We recognized six species as new occurrences for APA Abaeté: Catasetum roseoalbum, Eltroplectris calcarata, Habenaria schenckii, Liparis nervosa, Pelexia viridis and Prescottia leptostachya. Epistephium williamsii, Galeandra montana, H. schenckii, P. viridis and Vanilla palmarum deserve immediate conservation actions in order to avoid local extinctions. The mentioned species form small populations (less than 50 individuals) and/or are restricted to up to three plots. Deforestation, occasional changes in habitats, including illegal collection of plants, urban growth of the neighborhoods, and the possible expansion of the international airport in Salvador may drastically reduce the population sizes of the orchids present. Cyrtopodium parviflorum and Koellensteinia florida may be extinct locally; they were last collected last century and recent attempts to find them in the area were unsuccessful. Conservation efforts must include the management of species, environmental educational actions and the permanent control and surveillance of the area.