Use of Environmental Impact Assessment (EIA) tools to set priorities and optimize strategies in biodiversity conservation

Abstract

Pantepui is a biogeographical province composed of a group of approximately 50 tabular mountain summits, or tepuis, in the southeast of Venezuela. This region, also known as Guayana Highlands (GH), lies between 1500 and 3014m elevation and has an approximate extension of 6000km2. The summits of the tepuis are characterized by exceptional vascular plant diversity and high endemism. However, it is expected that ongoing global warming will produce upward displacements of summit taxa, which may cause the extinction of certain species due to habitat loss. This study assessed the potential extinction risk of the >600 Pantepui endemic vascular plant species during the 21st century due to global warming, revealing that 30–50% of endemic species would lose their habitat by the end of this century. In light of these results, prioritization of threatened species for conservation purposes became necessary. This was achieved through the calculation of an Environmental Impact Value (EIV) for each species, and a subsequent division of these species into priority categories, which should be used in a chronological sequence to guide decision-making and future research aimed at establishing the most suitable conservation strategies. A number of in situ and ex situ conservation alternatives were discussed. In situ conservation by means of designating protected areas does not appear a viable option because of the upward habitat displacement involved in this case. Conversely, seed banks, living plant collections and managed relocation were suggested in this chronological order to preserve the species studied here.