Diversity, ecology and community structure of the freshwater littoral diatom flora from Petuniabukta (Spitsbergen)

Despite the frequent application of diatoms in palaeoecological research in the High Arctic, our knowledge concerning the diversity, ecology, community associations, community dynamics and survival strategies of High Arctic freshwater littoral diatom floras is still rather limited. In the present study, the diversity, ecological characteristics and community structures of the freshwater littoral diatom flora from ponds and lakes of Petuniabukta (Spitsbergen, Svalbard Archipelago) were studied. In total, 87 samples from the littoral zone of 53 freshwater ponds and lakes were examined using light and scanning electron microscopy. A highly diverse diatom flora dominated by Achnanthidium and Nitzschia was observed. In total, 310 diatom taxa belonging to 59 genera were found, of which about one-third could not be identified beyond the genus level. Based on species composition, four main diatom communities were distinguished. Differences in environmental characteristics, such as habitat type, habitat diversity, habitat stability, streams, water pH and influence of the fjord, biota and human activities, appeared to be important factors in determining the observed diatom communities. The high number of unidentified taxa in this study indicates that a profound revision of the Arctic diatom flora is highly desired, not only to improve our fundamental knowledge concerning the diversity, ecology, community associations and biogeography of Arctic diatoms but also to aid applied (palaeo)environmental sciences