An estimate of the lower limit of global fungal diversity

We conservatively estimate that there is a minimum of 712,000 extant fungal species worldwide, but we recognize that the actual species richness is likely much higher. This estimate was calculated from the ratio of fungal species to plant species for various ecologically defined groups of fungi in well-studied regions, along with data on each groups' level of endemism. These calculations were based on information presented in the detailed treatments of the various fungal groups published in this special issue. Our intention was to establish a lower boundary for the number of fungal species worldwide that can be revised upward as more information becomes available. Establishing a lower boundary for fungal diversity is important as current estimates vary widely, hindering the ability to include fungi in discussions of ecology, biodiversity and conservation. Problems inherent in making these estimates, and the impact that additional data on fungal and plant species diversity will have on these estimates are discussed.