Macro-invertebrate communities associated with the macrophytes of Lake Vechten: structural and functional relationships

Abstract

The macro-invertebrates associated with eight species of emergent, floating-leaved and submerged macrophytes were recorded in May-June 1979. The plant species were: Phragmites australis, Sparganium erectum, Typha angustifolia, Polygonum amphibium, CeratophyIlum demersum, Elodea sp., Myriophyllum spicatum and Nitella mucronata. All macrophytes had a high number of macro-invertebrate species in common; however, some animals were also species-specific, particularly those occurring on the emergent plants. As regards the food source and feeding mechanism, the detritivores, periphytiscrapers and omnivores predominated, followed by predatory carnivores. The seston-filtrators also form a significant part of the community biomass. The macrofaunal distribution depended strongly on colonizable plant surface area and vegetation density. The macrofaunal communities of the Elodea, Ceratophyllum and Phragmites stands contributed mainly to the lake's carbon cycle. Being poorly represented by herbivores, the macro-invertebrate communities will affect the lake's primary production only slightly.