Diversity of green algae in Kamanos raised bog (NW Lithuania) with the aspect of long-term changes in desmids

In Kamanos raised bog, the green algae community was represented by 160 taxa distributed into eight Chlorophyceae orders. The diversity of desmids (93 taxa) that are an essential algal component of raised bogs was most relevant. Chlorococcales comprised 30 taxa and Ulotrichales – 15 taxa. Representatives from the rest green algae groups were scarce. Higher variety of habitats in Lake Kamanos and the pools supported more diverse flora of green algae (151 taxa) compared to black hollows (61 taxa). Actinotaenium cucurbita was the single species found in all studied water bodies of Kamanos raised bog. Characium ornitocephalum, Asterococcus superbus, Cosmarium amoenum, Micrasterias truncata, Spondylosium pulchellum, Netrium digitus were found in the lake and all pools, whereas Cosmoastrum scabrum, Tetmemorus laevis – in all hollows. In the current study, the composition of desmid taxa recorded in Kamanos raised bog in two research periods was compared. The first reports on desmids were published by Vilkaitis (1937, 1940). He found 129 Desmidiales (18 genera) and 10 Zygnematales species (4 genera). Fifty five species identified by V. Vilkaitis were found repeatedly during the current investigation. In 2005, 42 species were newly recoded in Kamanos raised bog, and of these, 17 taxa were new to desmid flora of Lithuania. A numerous rare species recorded by Vilkaitis (1937) were not observed repeatedly probably due to long-term changes that had occurred in the peat bog and not enough comprehensive study that represented only part of Kamanos wetland. Some new rare desmid species (e.g. Micrasterias jenneri, Cosmarium cymatonotophorum, Desmidium cylindricum, Actinotaenium cucurbitinum, Xanthidium bifidum) have recently been found at Kamanos sites.