The maximization or maintenance of diversity is a challenge unique to biodiversity conservation, one made more complex by the competing objectives of efficiency and equity, dealing with uncertainty and limited information, choosing allocations towards different policy options (for example between restoration and protection, between land sharing and land sparing, or between further research and action), and planning in the context of the values and capacities of stakeholders. In addition, we welcome presentations of modeling approaches that help us understand processes and patterns of biodiversity, including models of species and species interactions that elucidate these patterns, and the drivers of biodiversity and biodiversity decline.