Advantages and drawbacks of living in protected areas: the case of the threatened Erysimum popovii (Brassicaceae) in SE Iberian Peninsula

Protected areas help to develop regional and global strategies for the conservation of biodiversity. However, human-related activities, such as grazing, tourism, hardwood extraction, etc., may cause the decline of some species. In this study, we investigate whether inhabiting protected areas affect the conservation of Erysimum popovii, a narrow endemic and endangered plant, in Mediterranean environments with traditional human activities. We surveyed its entire distribution area in SE Spain, and located 31 populations, 16 within Nature Parks (Category V of the IUCN) and 15 in non protected areas. In each population we measured several variables related to habitat composition, pollinator community, herbivory damage and population viability. Our results show that populations in protected areas inhabit localities at higher altitudes and with more shrub cover. Most important, the abundance of a very effective pollinator type, beeflies, was significantly higher in protected populations. Curiously, damage by ungulates was also more intense in protected areas. The negative effect of herbivory offsets any positive effect played by pollinators in protected areas, and consequently there were not differences in population size or reproductive output inside and outside protected areas. It seems that allowing traditional uses in protected areas may entail negative effects for some vulnerable plant species.