A quantitative assessment of genetic erosion in ipecac (Psychotria ipecacuanha)

Abstract

In this study, we present a methodology by which the threat of genetic erosion to a wild plant species growing in a given geographic region can be assessed in a quantitative manner. Evaluation of threat is carried out by scoring a checklist based on information about the ecosystem and the target species. This approach was used to assess the threat of genetic erosion faced by ipecac (Psychotria ipecacuanha), an endangered medicinal plant that is native to the Atlantic Rain Forest of southeastern Brazil. An analysis of the spatial distribution of 20 risk factors over 14 forest fragments indicated that the threat of genetic erosion is not uniformly distributed over the region. The most endangered clusters of ipecac are facing presently a threat almost three times larger than that faced by the least endangered.We were able to identify the short distance of a forest fragment to the major population centres and thepoor conservation status of the species as the factors that present the major contribution to threat. The distance of a forest fragment to new development projects, the extent of the use of a wild habitat within a forest fragment, and the susceptibility of target species to grazing animals were considered the least important factors of risk. The results obtained by using this approach allowed us to formulate an itemized description of which category of forest fragments we should direct forthcoming expeditions with the aim of collecting germplasm of wild ipecac.