Biodiversity of lichens, including a world-wide analysis of checklist data based on Takhtajan's floristic regions

The similarity of lichenized fungal species composition among the 35 floristic regions recognized by Takhtajan was calculated, based on checklists of 132 geographical units and a first draft of a global checklist of lichens and allied fungi (which lists 18,882 species) to assess biogeographic and biodiversity patters of lichenized fungi. A nearest-neighbour cluster analysis of pair-wise comparisons of species composition data (Jaccard index of similarity) from these geographical units is presented. Four main geographical regions were identified: holarctic, subantarctic/Australian, oceanian, and pantropical. Possible changes of the global species number caused by increasing availability of molecular data are discussed. A prospect on future developments of lichen biodiversity research is provided.