From the origin of man onwards river systems have served as networks for exploration and development by mankind. Lowland river systems of Western Europe have been severely modified to serve human purposes. As a consequence engineering works in general reduced overall diversity in habitats and in patterns. Still, due to their high spatio-temporal heterogeneity and habitat connectivity, river systems belong to the most species rich ecosystems in temperate regions. Therefore conservation and restoration of river landscapes receive much attention today.

The Common Meuse forming the natural border between Flanders (Belgium) and the Netherlands can be considered as the most natural part of the River Meuse. Especially the gravel banks along its trajectory enclose a specific and rare arthropod fauna. With it river dynamics, by means of flooding disturbance, structure arthropod assemblages appearing on the gravel banks and the surrounding alluvial grasslands. Although being a threat for many species, typical riparian species are dependent of natural fluvial dynamics for the maintenance of specific environmental properties.

Within the scope of this research we try to found out to what extent flooding disturbance and interrelated habitat quality as well as landscape configuration cause shifts in spider and carabid beetle assemblages, and hence their life history traits. Therefore we aim to test following propositions:

1. Flooding disturbance causes alterations in biodiversity, metacommunity and local assemblage structure and life history traits of spiders and carabid beetles occurring on gravel banks.
2. Wolf spider populations (Lycosidae) from gravel banks with different inundation dynamics and orientation show adaptive plasticity in dispersal and flood-escape behaviour.
3. A riparian wolf spider thrives under a metapopulation structure, subject to the river directionality, whereas a generalist species is dependent of constant recolonization of the gravel banks.

These results will contribute to a better understanding of how assemblages, (meta)populations and life history traits therein, are structured within highly dynamic systems. Next to it, the research will add to the knowledge of riparian species and their possible use as bio-indicators. Overall suggestions can be made with regard to river management and the conservation ⁄ restoration of lowland river ecosystems. A whole new world lies open to be explored yet...