The paper reports a study of cyanobacterial diversity in a cold-water limestone limnocrene in Central Poland. Samples were collected from 1998 to 2000 and in June 2012. The morphology, population characteristics and species composition of the cyanobacteria assemblages were investigated, and the frequency of taxa was recorded. The large number of taxa identified (30) reflects the microhabitat heterogeneity of this spring. Some species considered epiphytes grew on limestone rocks. The occurrence of the majority of the most frequent taxa was related to the physicochemical characteristics of the spring, but none of them can be considered obligatory crenobionts characteristic of limestone springs. The studied spring is a unique ecosystem with an interesting cyanobacteria microflora whose occurrence is attributable to the spring’s water chemistry, low temperature and variety of microhabitats.
Qualitative analysis of algae, including microhabitats and vascular vegetation in a spring niche, together with basic physical and chemical characteristics is presented. 175 diatom taxa as well as taxa of macroalgae and vascular plants were determined in the spring niche, and the community types were defined. Seasonal variability of diatom communities was observed. The influence of a flood as a catastrophe on the community of diatoms and macroalgae was noticed.
Freshwater red algae Hildenbrandia rivularis has been noted for the first time in central Poland near the Lodz agglomeration. Until now, this alga was recorded only in mountain and Polish Lowland areas. The wide range of habitat conditions influencing the occurrence for this protected species has been determined in the spring niche. The possible threat to habitat where H. rivularis occurs, is connected with construction and exploitation of the A2 highway