Loose and firmly attached epiphyton: Their relative contributions to algal and bacterial carbon productivity in a Phragmites marsh

Abstract

The relative contributions of the loose and firmly attached epiphytic components to biomass, primary productivity (Na 2H 14CO 3 assimilation) and bacterial secondary productivity ( 3H methyl-thymidine incorporation) were studied on one occasion during spring in a Phragmites australis (Cav.) Steud. marsh on the highveld of South Africa (27° 53′E; 26° 19′S). The loose epiphyton contributed orders of magnitude more to algal and bacterial production than the firmly attached component and thus its exclusion or loss during sampling could result in a significant underestimate of total epiphyton production. Conversion of dissolved organic matter to a particulate form during bacterial production may be an important input to the grazing food chain of aquatic macrophyte communities.