The mycological properties of medieval culture layers as a form of soil ‘biological memory’ about urbanization

Abstract

The mycological properties of soil can offer information about ancient human–landscape interaction, including urbanization. This preposition has been confirmed in our study of the habitation deposits in the medieval Russian settlements (eighth to fourteenth centuries A.D.). The mycobiota of profiles of anthropogenically transformed soil of excavated medieval settlements were examined in different climate conditions in the European part of Russia. The fungal biomass and biomass structure were evaluated using luminescent microscopy. The isolation and enumeration of microfungi were performed using the method of serial dilutions of soil samples and plating them out on the number of solid media. The isolation of keratinolytic microfungi was performed by hear-bite technique. It was established that in ancient urban soils, the mycobiota may have properties different from those of zone fungal communities. The examined cultural layers of ancient settlements differ from the horizons of the surrounding natural soils because of a bigger rate of fungal spores in fungal biomass, more mosaic distribution of microfungal communities, different species composition and dominant microfungal species, increased incidence of some ecological, and trophic fungal groups (for example, keratinophilic, potentially pathogenic microfungi). The mycological characteristics of anthropogenic deposits in the excavated medieval settlements were found to be mainly similar to mycological properties of modern urban soils. These properties of habitation deposits can be interpreted as a kind of “soil mycological memory” of the ancient urban impact. Soil mycological characteristics could be used in paleoecological reconstructions and biomonitoring of urban impacts