Global Patterns of Liverwort Diversity, Distribution, and Floristic Knowledge EARLY LAND PLANTS TODAY: GLOBAL PATTERNS OF LIVERWORT DIVERSITY, DISTRIBUTION, AND FLORISTIC KNOWLEDGE

Liverworts (Marchantiophyta) are pivotal in our understanding of early land plant evolution and they form both a conspicuous and important component in many terrestrial ecosystems throughout the world. Studies of terrestrial diversity patterns on global scales, based on quantitative data, have been largely confined to vascular plants and animals. We here present a preliminary data set recording the distribution of liverwort species across almost 400 geo-political units based on almost 40,000 records from over 600 publications. This database is the most comprehensive catalogue of liverwort species worldwide, attempting to unify taxonomy, nomenclature, and distribution from the vastly scattered biological literature. The development of such a database has far reaching implications and applications, including relating biodiversity patterns to anthropogenic threats or to abiotic drivers of species richness. It also makes significant steps toward the compilation of a worldwide checklist of liverworts. Three examples are here demonstrated: i) a preliminary global map of liverwort species richness; ii) diversity patterns of the family Lejeuneaceae compared to the overall liverwort flora; and iii) we highlight centers of significant liverwort species richness that are totally neglected by well-known global diversity hotspots analyses. Although ther