Distribution and ecological niche modeling of a rare species Poronia punctata in Asia

The ability to identify the spatial distribution of rare fungal species is crucial for the understanding of the environmental factors that affect them and their conservation management. Maximum entropy spatial distribution modelling (MaxEnt) solves this problem by inferring species distributions and environmental tolerance based on the occurrence data. We constructed a map of the current and potential geographical distribution of the dung fungus Poronia punctata using this method. We included in the model 19 WorldClim bioclimatic variables with the corresponding altitude data, and 23 spatially well-dispersed species occurrence records. We defined the regularities in spatial distribution of P. punctata based on the occurrence data, as well as bioclimatic characteristics in order to control species status in the natural environment. The majority of the locations of P. punctata in Asia are placed in the middle mountains. In addition to the presence of a suitable substrate and the habitat type, the geographical distribution of P. punctata depends on a set of environmental factors that are optimal for this species. Optimal climatic conditions for P. punctata in Asia are typical for steppe communities and steppe shrub thickets of intermontane depressions of Lakes Basins and lowlands between mountain ranges. All species habitats were associated to the vegetation type of steppe and forest-steppe. Locations within the boundaries of Temperate Coniferous and Boreal Forest occurred in the habitats affected by anthropogenic activity and grazing, subjected to steppe formation; these locations were confined to river valleys and lakes, which also brings them closer to the habitats of depressions and lowlands. The points of presence occurring in intermontane depressions and lowlands between mountain ranges represent the environment core of P. punctata range in Asia.