B. Papp szerk.: Studia Botanica Hungarica 29. 1998 (Budapest, 1999)

Gönczöl, János; Révay, Ágnes: Aquatic Hyphomycetes in a tributary of the Morgó stream, Börzsöny Mts, NE Hungary

Studia bot. hung. 29, pp. 5-16, 1998 (1999) AQUATIC HYPHOMYCETES IN A TRIBUTARY OF THE MORGÓ STREAM, BÖRZSÖNY MTS, NE HUNGARY J. GÖNCZÖL and Á. RÉV A Y Dept. Botany, Hungarian Natural History Museum H-1476 Budapest, Pf. 222, Hungary Conidial populations of the Csömöle stream, Börzsöny Mts were sampled by membrane filtration. This tributary of the Morgó stream is a moderately hardwater stream with a riparian vegetation dominated by Carpinus betulus and Fagus sylvatica. In total 45 fungal species were collected of which 10 were detected throughout the study. Filosporella sp. was the only species dominant on every sampling date. The highest conidial concentrations occurred in December and the lowest in January. Unusually high proportions of the scolecospores were obtained in the conidial populations. Similarity indices reflected only moderate similarity between the fungal communities of the Csömöle stream and the lower section of the Morgó stream. Key words: aquatic hyphomycetes, conidial populations, scolecospores, tributary stream INTRODUCTION Aquatic hyphomycetes or Ingoldian fungi are important members of stream organisms colonising and decomposing allochtonous leaf and woody litter (BÄRLOCHER 1992). Spatial and temporal distribution of conidial communities of aquatic hyphomycetes has been studied in various types of streams in various climatic and geographical regions of the world. The spatial distribution of these fungi has recently been categorized by the scale on which they are detected (BÄRLOCHER 1987, FABRE 1998C). The distribution of aquatic hyphomycetes on a global or world scale appears to be decisively influenced by the climatic zones (INGOLD 1975, WOOD-EGGENSCHWILER and BÄRLOCHER 1985). Within the same climatic zone water chemistry, especially pH, has a controlling effect for the number of species coexisting in a stream (BÄRLOCHER and ROSSET 1981, WOOD-EGGENSCHWILER and BÄRLOCHER 1983, CHAUVET 1991). Spatial distribution of the aquatic hyphomycetes in a small area, for example in a stream or in a stream system has also been studied (GÖNCZÖL 1975, SHEARER and WEBSTER 1985, THOMAS etal. 1989, 1991, FABRE 1996, 1998A, b, c). Nevertheless our knowledge in this field is yet insufficient and further studies need to recognise general patterns of spatial dynamics of individual species in different kinds of streams or in stream systems. Studia Botanica Hungarica 29, 199K Hungarian Natural History Museum, Budapest