Pollinator diversity: distribution, ecological function, and conservation

By facilitating plant reproduction, pollinators perform a crucial ecological function that supports the majority of the world’s plant diversity, and associated organisms, and a significant fraction of global agriculture. Thus pollinators are simultaneously vital to supporting both natural ecosystems and human food security, which is a unique position for such a diverse group of organisms. The past couple of decades have seen unprecedented interest in pollinators and pollination ecology, stimulated in part by concerns over the decline of pollinator abundance and diversity in some parts of the world. This review synthesizes what is currently understood about the taxonomic diversity of organisms that are known to act as pollinators; their distribution in both deep time and present space; the importance of their diversity for ecological function (including agro-ecology); changes to diversity and abundance over more recent timescales, including introduction of non-native species, and a discussion of arguments for conserving their diversity.