Integrating economic costs into global biodiversity conservation priorities : sensitivity of prioritization to the use of differing cost indicators Protected area systems that are ecologically representative and effectively managed are essential tools for the conservation and sustainable use of biodiversity worldwide. However global protected area coverage and management effectiveness is highly insufficient even in areas of global biodiversity significance. Under the Convention on Biological Diversity (CBD) governments committed to improve management effectiveness and expand the global coverage of protected areas from 13% to 17% of land area by 2020 targeting especially areas of particular importance for biodiversity. It is importa...