Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 71. (Budapest 1979)

P. Komáromy, Zs.: Algal flora of Hungarian sandy soils I. Some algological investigations in Kiskunság National Park, Hungary

these patches with moving sand but they can be found under the ripple-marks and among the grass tussocks. Forty-three species of terrestrial algae were identified from 108 soil samples which were collected from four sampling areas: 30 blue-green, 7 green, 3 yellow-green and 3 diatoma species. Considering the presence and absence of the species, it was established that the species of Cyanophyta are dominant in all of investigated places (69.7 per cent of total species number). Most of the species belong to the genera of Phonnidium and Gloeocapsa (26.19 and 14.28 per cent, respectively). However, the majority of them were identified from few soil samples, e.g. Gloeocapsa granosa, Gl. kuetzingiana, Gl. muralis, and Phormidium fragile, Ph. frigidum, Ph. interruptum, Ph. molle, Ph. paulsenianum. On the other hand, the most widespread Cyanophyceae species were the following (in decreasing order of frequency): Microcoleus vaginatus in 65, Synechococcus aeruginosus in 30, Phormidium ambiguum var. maior in 23, Lyngbya hieronymusii in 22, Nostoc commune in 12 and Phormidium foveolarum in 12 soil samples. The other divisions participate in the total species number as: Chlorophyta 16.27 per cent, Xanthophyta 6.97 per cent and Bacillariophyta 6.97 per cent. The ecological dissimilarities which manifest themselves in the structures of flowering plant associations, may also be studied on the species composition of soil algal flora. In spite of the fact, that rather few samples were examined from Bugac, Izsák and Örkény, it can be established that there are species which occur only in one or another locality. Namely, Anabaenopsis sp., Gloeocapsa granosa, Gl. kuetzingiana, Gl. muralis, Phormidium fragile, Ph. frigidum. Ph. molle, Stichococcus bacillaris, Chlorocioster terrestris and Monodus subterranea occur at Fülöpháza, Lyngbya limnetica, L. martensiana, Phormidium paulsenianum and Elllpsoldion sp. at Izsák, while Microcoleus lacustris and Phormidium interruptum at Örkény. If we pay special attention to species frequency we have the following list: Chlorhormidium crenulatum (78.7 per cent), Microcoleus vaginatus (60.19 per cent), Hantzschia amphyoxis (56.48 per cent), Pinnularia borealis (46.29 per cent), Synechococcus aeruginosus (27.77 per cent), Phormidium ambiguum (25.92 per cent), Phormidium ambiguum var. maior (21.29 per cent) and Lyngbya hieronymusii (20.37 per cent). It is to be noted that Hantzschia amphyoxis and Pinnularia borealis usually occurred as silicon frame so their frequencies were not real values. The climatological and edaphic effects are of paramount importance in the construction of plant communities. The factor interaction between temperature and moisture, relatively as well as absolutely, is a well-known fact. This interaction is demonstrable in sandy lands. The monthly mean temperature increases from spring to summer and decrease from summer to autumn. The moisture content of the soil, originating from melting snow, decreases rapidly accompanied by a rapid increase in soil temperature. The precipitation cannot retrive the defficiency of water, as an issue of evaporation. In spite of this, the frequency of the species is rising gradually during the examined period. In late April the soil moisture content reaches its lowest level, but the decrease of species number cannot be observed in early May, and no diminution of frequency manifested itself, since smaller rainfalls from time to time moistened the soil surface, so some of the species could multiply there. In July, owing to an unusually wet weather (monthly precipitation amount was 105 mm), both species number and frequency reached a rather high value. In April, when the sand was practically dry, Chlorhormldium crenulatum (22), Microcoleus vaginatus (12), Phormidium ambiguum (7), Aphanocapsa biformis (4), Phormidium ambiguum var. maior (3), Cylindrocystis crassa (3), were present (Table 1). The observed algal cells were in the vegetative stadium. The filaments of Chlorhormidium crenulatum were winding Spirulina-like. The majority of the cells aoparently were complete vegetative cells, but in some of them