The mycological investigations were performed on three soil profiles, which represent the slightly, moderately and strongly mucked peat-muck soils located in the Biebrza Valley. The aim of the study was the comparison of quantitative-qualitative structures of the fungi communities in the chosen peat-muck soils. The results indicate that soil fungi communities from compared soils reveal only small degree of similarity. The variety in quantitative and in qualitative structure increase with increasing mucking of organic deposits. These results may suggest that decreasing moisture of habitat stimulates the development of soil fungi. The most numerous soil fungi communities were observed in the turf layer and subturf layer of all soils.
The study was conducted in the years 2003-2004 on four low peatland peat soil profiles located in the Narew National Park. All studied soils were sedge peat soils sampled from various habitats. The recognition of the soil fungi communities and their stratification in the studied profiles were the aim of the study. The 214 isolates were made, which were represented by 45 species. The reason for little differentiation of quantitative-qualitative structures of soil fungi communities in peat soils is their high moisture. The distinct differentiation among the soil fungi communities was observed. These results suggest that not only the soil-forming process affects the soil fungi communities development but also the soil properties, which were under influence in the past and have been still affected by the habitat conditions, are very important to the development process of soil fungi communities.
The aim of the studies carried out in the natural oak-hornbeam forest Tilio-Carpinetum typicum and in the degenerated form in the stage of pinetization Pinus-Lamniastrum, was to obtain and compare qualitative-quantitative structures of soil fungi communities in two different oak-hornbeam forests. This degenerated form of oak-hornbeam forest is the result of removing the natural tree population (typical oak-hornbeam forest) and re-afforesting the resultant vacant area with pines. The study plots were located in such a way that the variations of soil fungi communities were affected only by seasonal changes in the vegetation of the degenerated oak-hornbeam forest Pinus-Lamnias- trum. The soils in both study plots are typical forest grey-brown podzolic soils (Luvisols). The results of mycoiogical studies indicate significant differences between soil fungi communities in both oak-hornbeam forests, although similarities especially in species composition of 15 of the most abundant fungi species were also found. The differences are the result of changes in the floral composition of degenerated oak-hornbeam forest. In the past, when typical oak-hornbeam forest covered whole studied areas, the soil fungi communities were probably almost the same in both plots. The first change could have happened after the removal of the trees; the second, after the re-afforestation of the resulting vacant area with pines. The re-appearance of Tilio-Carpinetum typicum in its once occupied habitat causes changes in the soil fungi community in the degenerated oak-hornbeam forest.