A comparison of diatom epiphytes, their diversity and density, attached to myriophyllum spicatum l. In norfolk dykes and broads

Abstract

Diatom epiphytes were collected from six dyke sites and six Broad sites, of contrasting nutrient loadings, on three occasions during 1976. Diversity indices were higher in the Broad sites than in the dyke sites and the diversity indices in the Broad sites also increased from the first sampling date to the second and third sampling dates. The results are discussed with reference to diversity changes and mechanisms thought to occur in phytoplankton populations. Epiphyte density was higher in the dyke sites than in the Broad sites, probably due to increased nutrient loadings in the dykes. This result is discussed in relation to a recently constructed model to account for the decline of aquatic macrophytes in progressively enriched freshwaters. © 1978 Taylor & Francis Group, LLC.