Distribúcia cyanobaktérií a rias na stavebnom kameni Presbytéria Dómu sv. Martina v Bratislave

Rok, strany: 2006, 11 - 20

The distribution of cyanobacteria and algae on building stone was studied at one locality (8 sampling sites) – St. Martin’s Cathedral. The occurrence was investigated on the lower one meter of the Presbyterium of St. Martin’s Cathedral and the occurrence of algae and cyanobacteria was studied under a microscope using samples collected from 4 types of substrata from both the northern and southern side of the Presbyterium part. Overall, 4 species of cyanobacteria, 1 rhodophyte, 8 hetero-konthophytes and 14 chlorophytes, were recorded. There was no major difference in frequency of cyanobacteria and green algae either for aspect nor for substrata type. Heterokontophytes were more frequent on the northern versus the southern side of the monument. This indicates that there were significant differences in the microclimate between the N (north)- and S (south)- aspects on the different types of building stone. This enabled the survival and establishment of Heterokontophytes on the north-facing side of the Presbyterium which was characterized by shadier and more humid conditions. There was a weak correlation between the relative abundance of algae and cyanobacteria with regard to the North- and South-aspects on four rocky substrata (stone blocks). Only the siliceous substrata indicated a significantly lower diversity of representatives. In the distribution of green algae and cyanobacteria, the lack of correlation may be explained by interactions with other organisms, i.e. mosses. It was concluded that retained building stone in an urban area characterized by a microclimate are likely to function as substrate for new establishment of cyanobacteria and algae. This was observed on the north-facing side of the Presbyterium, where conditions were good for Heterokontophytes to prevail