Vegetation-environment relationships were investigated in fens of the Třeboň basin, that are enriched by nutrients and calcium from intensively managed and limed fishponds. Vegetation types differed significantly in water table depth, water pH and Ca2+, Mg2+, K+, and NO3- content. The concentration of major nutrients fluctuated noticeably during vegetation season and displayed large variation within vegetation types. High nutrient supply has not altered the gradient structure of the vegetation. Water pH and water table depths were found to be two major determinants of species variation in fishpond-margin fens. Species richness of both vascular plants and bryophytes was controlled by pH. However, extent of variation in mineral richness as well as potassium concentration accounted for the next two most important variables determining bryophyte species richness.