Spatiotemporal distribution of soil microfungi in the Makhtesh Ramon area, central Negev desert, Israel

We examined the spatiotemporal pattern of soil mycobiota structure in the area of Makhtesh Ramon - a unique erosion cirque located in the central Negev desert, Israel. A total of 185 species from 76 genera were isolated using the soil dilution plate method. Most microfungal communities from sunny open localities were characterized by a dominance of melanin-containing species with large, thick-walled and multi-celled conidia increasing in the summer. By contrast, in the shrub communities, dark-colored species with comparatively small one-celled conidia prevailed. Aspergilli (mainly Aspergillus fumigatus) and teleomorphic ascomycetes comprised a basic part of thermotolerant mycobiota obtained at a temperature of 37 °C. Diversity (heterogeneity, evenness) was highest in the edaphically extreme localities and decreased in the climatically extreme summer season. The results demonstrated that the soil of the Makhtesh Ramon area maintained comparatively rich microfungal diversity subjected to spatiotemporal variations apparently adaptively influenced by variations in microclimatic and edaphic conditions.