B. Papp szerk.: Studia Botanica Hungarica 33. 2002 (Budapest, 2002)

Buczkó, Krisztina: A new floristical survey of the algal flora of the Babat valley, Hungary

the ponds. Closterium ehrenbergii, Cosmarium humile (Zygnematales, Chlorophyta) can be mentioned as well as a Staurastrum species as some of the uncommon species. In March, Oedogonium sp. was found. Eunotia bilunaris is a noteworthy diatom; it is a common and character species of swamps at least in Hungary. Rhopalodia gibba individuals of huge size (up to 250 um) were very peculiar in the microscopic view. Surprisingly, Cylindrospermopsis raciborskii, the very common, toxic cyanobacteria, being quite often the mass forming species of water blooms, was found in this clear pond and only here, nowhere else in the Babat valley. The Goose Ponds (Nos 8 and 9) The smallest number of taxa per lake (41) was identified in the Upper Goose Pond (No 9). In spring, the dominance of flagellated algae and Chlorophyta was the most characteristic. In March, Micractinium pusillum was the dominant species in the ponds, while in summer Microcystis aeruginosa was a mass forming one, causing water bloom. There is a small hole at the sluice gate of the Upper Goose Pond. The gate was made of concrete; inside the hole, on the concrete wall a thick brown layer was collected which mainly consisted of diatoms. The species composition of this sample reminded us the flora of cave entrances. Aerophytic species, Hantzschia amphioxys, Navicula mutica and N. contenta was also identified, and Nitzschia palea was well represented in this layer. Angler Pond (No. 3-4) The dominance of flagellated algae is the main character of the algal flora of this pond. In summer, Microcystis aeruginosa caused water bloom. The presence of Chlorococcales (Chlorophyta) is also peculiar, experienced parallel with the decrease of diatoms. This is a well-known feature of eutrophic ponds and lakes. Lower Pond (No. 1-2) There are no significant differences between the flora of these and the upper (Angler Pond, No. 3-4) ponds. No surprise; the distance between the source of pollution and the inflow is short, and the amount of incoming water of the Aranyos stream is small. These factors are insufficient to absorb the effects of manure.