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

Table 2. Species composition of the leaf litter in the stream bed. Species average % Acer pseudoplatanus L. 26.5 5.3 Carpinus betulus L. 226.0 45.2 Fagus sylvatica L. 159.0 31.8 Quercus cerris L 16.5 3.3 Quercus petraea (Mattuschka) Lieblein 9.5 1.9 Salix caprea L. 3.5 0.7 Salix cinerea L. 18.0 3.6 Tilia cordata Miller 39.0 7.8 Tilia platyphyllos Scop. 2.0 0.4 conidia collected in the six samples) belonged to scolecosporous species. Extremely high proportions of scolecospores were obtained in the summer samples (93.7% in June, and 89.4% in August). Altogether 10 species were observed as being present throughout the study but with different conidial numbers. The most prolific species were - Alatospora acuminata s.l., Filosporella sp., Tricladium angulatum, Flagellospora leucorhynchos and Anguillospora sp. 1 - which together accounted more than 80% of the conidia collected during the study. Of these only one species, Filosporella sp., occurred among the top-ranked species on every sampling occasion. The other four species varied in the timing of their maximum conidial production. Anguillospora sp. 1 peaked in April and June, whereas Tricladium angulatum was most abundant in October and December. The number of conidia of Alatospora acuminata s.l. and Flagellospora leucorhynchos was extremely high in December. Further 7 species occurred frequently (proportion of conidia greater than 5% of total at least one occasion) in the water samples (Fig. 2). The maximum number of conidia of Lemonniera aquatica at Site Cs (245/1) was similar to those of at Sites V and VI (251.5/1; 192/1) of the Morgó stream, but because of the large conidial production of other species its relative proportion was lower than 5% in the Csömöle stream. In the comparison of the Csömöle stream with the six sites of the Morgó stream the similarity indices showed high similarity between their fungal communities only on the basis of presence and absence of species. However, when the relative frequencies of occurrence were taken into account, the similarity indices considerably decreased. On the basis of relative frequencies of species the structure of fungal communities of the Csömöle stream is most similar to the most lower site of the Morgó stream. The relatively high similarity value (45.01)