Fungal Diversity

This work examines the distribution of aquatic hyphomycetes in streams of the Northwest Portugal with different environmental conditions. Five sites are in the Ave River basin in an area with high population density, intensive agriculture and industrial activities. Other three sites are in the Cávado River basin and belong to the Peneda-Gerês National Park. Despite this survey has been conducted within a small area and during a short period of time, high aquatic hyphomycete species diversity was found. A total of 113 fungal taxa were identified at least at the generic level, of which ca. 90 % were classified as aquatic hyphomycetes in the traditional sense. Several rare aquatic hyphomycete species were found, of these five are reported here for the first time in the Iberian Peninsula and seven are new records in Portugal. The highest species richness was found at the spring of the Este River- Ave River basin (77 taxa) and in streams at the National Park (40-58 taxa). A decline in the richness of aquatic hyphomycete species was found at polluted sites of the Ave River basin (23-29 taxa). The distribution of aquatic hyphomycete species by cluster analysis and CA ordination opposed polluted and non-polluted sites, suggesting that water chemistry was the main factor regulating the structure of aquatic hyphomycete communities