Monitoring van ecologische effecten van milieuveranderingen, parameterkeuze en stratificatiebasis

Three institutes, Statistics Netherlands (CBS), the National Reference Centre for Nature Management (IKC-N) and the National Institute of Public Health and the Environment (RIVM), jointly coordinate the Ecological Monitoring Network (NEM), which was set up to collect relevant information for the Dutch government on the state of nature in the Netherlands. One of the NEM's objectives is to monitor the changes in flora and fauna caused by the changes in environmental factors (mainly acidification, eutrophication and desiccation). To realise this objective on a national scale, the changes in flora and fauna related to the changes in the abiotic conditions (environmental quality) will have to be charted. This is important for assessing how far environmental and nature policy guarantees the occurrence of flora and fauna. Creating a monitoring network that will be as efficient as possible will demand a stratification of the Netherlands into the most possible homogeneous areas, at least where expected abiotic changes are concerned. It is also efficient to consider only the flora and fauna parameters (variables) most vulnerable to environmental changes. The study has investigated the flora and fauna parameters giving the most state-of-the-art information on the effects of changes in environmental quality on the natural surroundings and habitat. Species groups, higher plants, butterflies, dragonflies and lichens, were found to be the most suitable, while summer birds and amphibians were found moderately suitable. Ultimately, 14 strata showing desiccated or non-desiccated areas were distinguished