Studies on the aquatic Hyphomycetes of the Morgó stream, Hungary. I. Longitudinal changes of species diversity and conidial concentration
Gönczöl, János; Révay, Ágnes; Csontos, Péter
Archiv für Hydrobiologie Volume 144 Number 4 (1999), p. 473 - 493
published: Mar 24, 1999
ArtNo. ESP141014404006, Price: 29.00 €
Conidial populations at six sampling sites along the main channel of the Morgó stream system in Hungary were sampled by membrane filtration. The stream is of typical soft water at the upper sites and slightly or typically alkaline at the lower sites. Percentage occurrence of the fast processing leaf types in the stream bed increased substantially downstream. In total, 69 fungal species, mainly Ingoldian fungi, were detected by water filtration. Species numbers and conidial concentrations of aquatic hyphomycete species increased simultaneously downstream up to Site IV, and then generally decreased. Fungal species richness and diversity were always highest at Site IV. Similarity indices reflected only moderate differences between fungal communities of neighbouring sites but substantial differences between more remote sites. The highest indices of similarity occurred between Sites III and IV. 38 % of all species were found at all the sites and slightly more than 10 % were restricted to specific sections of the stream. Only three species, Alatospora acuminata, Flagellospora curvula and Heliscus lugdunensis, occurred frequently at all the six sites. Principal components analysis was used to describe species distribution among the sites. Longitudinal changes in species numbers of the fungal communities of the main channel and conidial concentrations are discussed as affected by the spatial heterogeneity of the lotic environment and by a tributary.