Impact of hydrology on floodplain lake ecosystems along the lower Rhine and Meuse

Contains fulltext : mmubn000001_187464375.pdf (publisher's version ) (Open Access)Promotores : C. den Hartog en G. van der VeldeIX, 196 p

Diversity, occurrence and feeding traits of caddisfly larvae as indicators for ecological integrity of river-floodplain habitats along a connectivity gradient

In order to assess ecological values of Lower Rhine and Meuse floodplain habitats we studied the spatial and seasonal variation in diversity, species assemblages and feeding traits of caddisfly larvae in water bodies over the lateral connectivity gradient: eupotamon: main and secondary channels: parapotamon: channels connected permanently with the main channel only at their downstream ends; plesiopotamon: disconnected channels close to the main channel; paleopotamon: abandoned meanders at a greater distance from the main channel.<br>Spatial variety was studied by analyzing the summer species composition in 70 Lower Rhine and Meuse water bodies which were categorized in connectivity habitats, whereas seasonal variety was studied in Lower Rhine water bodies along a connectivity gradient by monthly sampling over a whole year. Physico-chemical data and environmental parameters were recorded for each water body during sampling. Diversity and species assemblages of caddisfly larvae varied in relation to connectivity, macrophyte diversity and abundance and stream velocity. A comparison with historical records and species lists from less disturbed rivers showed that diversity in the main channel was very low.<br>Caddisfly larvae species assemblages varied over the connectivity gradient. Lotic habitats (eupotamon) were separated from the lentic ones, and the well vegetated paleopotamon from the sparsely vegetated parapotamon and pleisopotamon habitats, indicating the overall importance of vegetation and current velocity for the species assemblages. Hydropsychidae have been found in the eupotamon exclusively, whereas Limnephilidae, Hydroptilidae and Polycentropodidae have been found predominantly in the paleopotamon water bodies. Leptoceridae were found in all floodplain water body categories. A similar pattern of distribution of families along the lateral connectivity gradient was found in more natural rivers.<br>Caddisfly larvae species feeding traits showed a clear differentiation over the lateral connectivity gradient with filter-feeders and scrapers most important in the eupotamon and parapotamon, and shredders, piercers and predators most dominant in the paleopotamon habitats, indicating the importance of nutritional resources in relation to hydrological connectivity for the structure and functioning of caddisfly larvae species assemblages. The analysis of the species feeding traits allows generalizations towards the entire aquatic community and general prognoses for other floodplain ecosystems

Growth and morphological responses of four helophyte species in an experimental water-depth gradient

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Biometrics and fecundity of the freshwater shrimp, Caridina nilotica (P. Roux, 1833) (Decapoda, Caridea, Atyidae) in the lower Nile river (Egypt)

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Effects of Substrate Parameters on Growth-Responses of 8 Helophyte Species in Relation to Flooding

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Effects of exotic amphipod invasions on fish diet in the Lower Rhine

To assess the importance and effect of recent exotic species invasions on components of food webs of common Lower Rhine biotopes (breakwaters and channel-connected sandpits), the diets of two important macrozoobenthivores, perch (Perca fluviatilis L.) and eel (Anguilla anguilla (L.)) were compared before and after invasions of exotic Amphipod