The Influence of the Spatial Structure of Hydromacrophytes and Differentiating Habitat on the Structure of Rotifer and Cladoceran Communities

Abstract

Research on the similarity of zooplankton in various stands of water vegetation, including rushes (Typha angustifolia), nymphaeids (Nymphaea alba) and submerged macrophytes (Charahispida, C. tomentosa, Myriophyllumverticillatum and Utricularia vulgaris) was carried out on the shallow Wielkowiejskie lake (Poland). The analysis of the similarity of the Rotifera community revealed the strongest relationship between the Myriophyllum and Chara tomentosa beds, with C. hispida attaching them. A second pair of habitats was represented by Typha and Nymphaea stands. Cladocerans revealed the greatest similarity between both zones of Chara. Additionally, two more pairs of habitats were distinguished – Typha and Nymphaea and also Utricularia and Myriophyllum. In most cases, the Shannon-Weaver values were high among macrophyte stations. Forward stepwise regression revealed that the length of Nymphaea stems was a single negative predictor determining the Cladocera densities. The water lily stand possessed the richest pelagic community of zooplankton and had the highest cladoceran diversity index. In accordance with CCA-ordination, out of the environmental variables, the macrophyte stem length and the concentration of P_tot were the strongest predictors in determining the distribution of particular species of the zooplankton community. Mainly pelagic species displayed preferences towards physical parameters of habitat, which is manifested in their greater affinity to a denser spatial structure of macrophyte substratum. The similarity of zooplankton communities in Wielkowiejskie lake was based on the characteristic architecture of particular macrophyte species, where the plant length was the strongest predictor. Moreover, the character of the zooplankton communities was also influenced by the concentrations of chlorophyll ‘a’ and the chemical variables, with the strongest impact of P_tot, of periphyton received from a particular macrophyte habitat and from water filling the spaces between plant stems.