Vertical Divergence of Cultured Microfungal Communities Through the Depth in Different Soil Formations at Nahal Nizzana, Western Negev Desert, Israel

We examined the depth-wise distribution of microfungi through 0-50-cm crusted sandy and playa profiles at the Nizzana research site, the Negev desert, Israel. A total of 188 species from 77 genera was isolated using the soil dilution plate method. Density of microfungal isolates sharply decreased with depth highly positively correlating with organic matter content at the sandy profiles. High load of solar radiation (at the surface) as well as strongly limited aeration, water infiltration, and increased salinity (at the playa depth) led to dominance of melanin-containing species with large, multicellular conidia both in the topsoil of all profiles and in the deep playa layers, while at 1-30 cm, species producing light-colored small one-celled conidia mostly prevailed. In that way, the above vertical variations resemble differences in the composition of topsoil microfungal communities found between the sites located in the Negev desert and in the Mediterranean region of Israel.