Selecting relevant areas for biodiversity conservation

The alarming biodiversity loss that witness since some decades ago requires the development of efficient conservation strategies. As conservation is generally expensive and the available resources are limited, the establishment of priorities becomes essential in order to optimize the balance between benefits and costs. Identifying outstanding areas of biodiversity at different scales of the territory can be one of the criteria, but not the unique one, used to prioritize areas for conservation. The ultimate aims may be completing reserve networks, identifying potential impacts caused by civil engineering and propose actions to mitigate them, or prioritizing ecological restoration projects. In this article we explain the results of four case studies. Three of them refer to vertebrate species in the Iberian Peninsula and the Balearic Islands and in Castille-La Mancha, and they apply a Combined Index of Biodiversity that synthesizes the characteristics of species richness, rarity and vulnerability. The fourth case study has to do with tree diversity in a tropical montane landscape in The Highlands of Chiapas ( Mexico), and uses a combination of forecasting models of alpha-diversity and the complementarity of forest communities (beta-diversity) to establish priority areas for conservation.