Ecosysteembenadering & Voedselweb

Central theme in the national and international policy for the rivers, lakes and estuaries in the Netherlands is the pursuit of robust, dynamic and resilient nature in synergy with other uses.
In order to achieve this, knowledge is required about the ecological functioning under the current and future conditions. To be able to better assess the effects of management practices, current use and development in rivers, lakes, and estuaries on its food webs and ecological carrying capacity it is important to incorporate environmental factors and processes on ecologically relevant spatial scales.
Besides the relevance of processes on the local habitat scale for ecosystem functioning, also larger-scale processes play an important role, which often transcend landscape boundaries. For example, the food webs of the lakes and estuaries in the Netherlands are fueled by the transport of material from rivers and their basins or via the water outlets of polders.

In this study landscape-transcending ecosystem links on large spatial scales are analyzed and its importance for ecosystem processes in the receiving systems is quantified in relation to nature policy targets regarding biodiversity, restoration and economic activities related to the ecosystem.

Biotic interactions are investigated in relation to primary and secondary production on the lower trophic levels (phytoplankton, phytobenthos, macrophytes, zooplankton, zoobenthos) and the links to the higher trophic levels (fish, birds) to better understand the food web structure and the role of spatio-temporal dynamics therein, as well as that of non-trophic relationships between species. 
Policy makers and water managers could use this knowledge to make decisions about interventions that have the intention to improve the ecological functioning of aquatic ecosystems, because its gives insight into the spatial scale which have to be taken into account for restoration measures to be effective.