Modelled habitat suitability of fungi in floodplains

To maximize restoration efforts, knowledge on habitat key structures and potential for species occurrence is crucial for conservation. Contemporary protected areas such as national parks and nature reserves can provide refugia for fungal species. Still, the relative importance of single areas might vary across species, especially as they might have been chosen according to other criteria (e.g. endemism vs species richness). Despite the knowledge on the important role of fungi in floodplains e.g. for decay processes, little is known about fungal species distribution and important factors for species conservation in this dynamic habitat. The national database on Swiss fungi with 615'000 records is to date mainly based on citizen science data, i.e. biased in many ways with a strong focus on macrofungi. Nevertheless we show that species with more than 100 observations can form a robust set for modelling. In this study, we focus on modelling the ecological niche along rivers in Switzerland for 17 riparian fungal species in a 25 x 25 m grid representing various functional groups (ectomycorrhiza, saprobic soil fungi, dead wood species). We predict areas of suitable habitat based on environmental predictors which cannot be influenced by management (e.g. soil characteristics, temperature and precipitation) and contrast it with models additionally including forest structures. Our results show that the two modelling approaches differ considerably in their predicted habitat suitability for the fungal species. While a majority of individuals of all species is currently reported to occur in protected landscape, areas with high habitat suitability varies considerably among species and does not overlap with key areas for conservation. The modelling approaches allow to detect potential habitat for individual species. Moreover, candidate regions for new key areas for conservation for a maximum number of fungal species can be defined in order to optimize conservation efforts under space constraints along rivers.