Data from: Multiscale patterns of rarity in fungi, inferred from fruiting records

Aim: It is unknown whether fungi show similar trends to other organisms in their macroecological patterns of abundance and spatial distribution. Here, we investigated fungal abundance-occupancy relationships to determine whether fungi that are common at a local scale tend to be more widely distributed. Location: UK and Switzerland Time period: 1950 - 2014 Major taxa studied: Fungi Methods: We used a local dataset of fruiting records of 2,319 species in the UK, accumulated over 65 years, and one from Switzerland of 319 species, spanning 32 years. Using record number and occurrence as proxies for abundance, in each case we examined the form of species and rank abundance distributions, and compared these with distributions of records in the national databases over the same time. We plotted relationships of local number of records and regional occupancy, and calculated multi-scale indices of rarity for all fungal species. Results: There was a remarkable congruence in the patterns found in the UK and Switzerland. Regional assemblages are characterised by many rare species, while few are common (fitting the lognormal distribution). However, at local scales, distributions best fitted a power law, suggesting that habitat availability or dispersal processes may play important roles. Fungi with high local record number are densely distributed nationally, but unlike other organisms, locally rare fungi may also be densely distributed at a wider scale. Main conclusions: Fungal fruiting records can be used to infer patterns in fungal distributions. Abundances in local assemblages may be determined by the position of the assemblage in the overall geographic range of each species, dispersal ability and environmental filtering. We advocate the use of multiscale approaches to rarity in future fungal sampling programmes, to provide more reliable information for future conservation policy decisions and fungal biogeography.