Soil fungal communities in a young and an old Alnus viridis coenosis

Soil microfungal communities of two adjacent, but differently aged Alnus viridis coenoses were studied using the soil dilution plate method. A total of 84 taxa were isolated: 59 from the young community, 51 from the old and 26 taxa shared. Mortierella parvispora and Pythium sp. had the highest density values in the young and the old alder community, respectively. Species compositions were compared between plots of the two communities using a metric multidimensional scaling and a correspondence analysis. Both analyses grouped plots from the young and the old community separately, suggesting a correlation between the changes in the fungal species composition and the age of the alder communities. The correspondence analysis produced two species groups more related to one set of plots or the other, together with another group formed of Mortierella, Micromucor, Geomyces and Trichoderma species, whose distributions were more closely related to the general abiotic conditions than the age of the alder communities. It is proposed that the significant differences in the composition of the two fungal communities mirror the existence of a seral fungal succession paralleling the aging of the alder communities.