Ecological data for an orchid diversity hotspot show that the subtribe Laeliinae may be endangered in the Brazilian Atlantic Forest

Abstract

The Brazilian Atlantic Forest harbours a mega diversity of seed plants. The Parque Nacional do Itatiaia is a large and mature Atlantic Forest remnant in southeastern Brazil. It includes around 10% of the Brazilian orchids and is considered a priority area for conservation. Thirty‐three species of the neotropical and very ornamental subtribe Laeliinae (Orchidaceae) have been recorded in this park, but according to our studies 13 species may be extinct locally. Here, we present ecological information, including population size, vertical distribution and orchid‐phorophyte for each species. In addition, we discuss the main factors threatening the species and the fact that official conservation policies following IUCN Red List categories and criteria at regional levels may be inappropriate for geopolitical regions, especially for overly restricted geographical areas. For this reason, some questions need to be addressed: 1) when should a decision maker be formally advised of the possibility of a species being threatened in a state, municipality or a conservation unit? 2) Below what minimum number of individuals in a population should conservation efforts (financial, logistical, etc.) be applied? These issues are particularily worrying when dealing with epiphytic orchids. For developing countries, these concerns are especially important since resources available to support biodiversity conservation actions are usually very limited. In addition, the lack of permanent control of legally protected areas, and difficulties to combat natural disturbances and predatory human activities also contribute to worsen the problems intrinsic to the conservation of these areas.

Orchidaceae in the Parque Natural Municipal da Restinga de Praia do Forte, Bahia, Brazil

“…The other species have not yet been evaluated, but, as they have wide geographic distributions, it is likely that they are also not at imminent risk of extinction. Nonetheless, many Orchidaceae species are subject to predatory collection due to their high ornamental value, often resulting in population reduction or local suppression, this scenario being more likely in areas where the plants are more easily accessed (Cruz et al, 2003;Barberena et al, 2018a), as is the case with restingas. In the PNMR Praia do Forte, we observed that some species have small populations (<50 individuals) and restricted local distribution, and, therefore, require the attention of managers, in order to implement possible management and conservation actions and prevent them from being suppressed locally.…”

Distribución espacial de Vanilla bahiana (Orchidaceae) en dos fitofisonomías de restinga. ¿El patrón espacial varía?

“…Las especies de orquídeas son particularmente vulnerables a la extinción, ya que, entre otros factores, con frecuencia tienen poblaciones reducidas, con una distribución restringida, y dependen al menos parcialmente de los hongos, principalmente, con respecto a la germinación y el desarrollo de plántulas (Batty et al, 2001;Barros, 2007;Pandey et al, 2013). Además, están sujetas a colecciones depredadoras por coleccionistas y comerciantes, que alimentan el comercio ilegal activo (Barros et al, 2007;Barberena et al, 2018).…”