The importance of a hierarchical ecosystem classification for the biological evaluation and selection of least valuable sites

This paper suggests that for assessment studies, divisions into a core region (ecoseries), an immediate surrounding (ecosecction) and a wider surrounding (ecodistrict) should be used in ecosystem classification. A methodology to classify sites was set up and, making use of ten sites for biological evaluation in Belgium, it was shown how a hierarchical ecosystem classification could improve categorisation. Often the visual characteristics of the surrounding landscape, such as diversity or connectivity, mask the features of the core zone itself (ecoseries). Using different hierarchic ecosystem levels is a direct and effective help to avoid this masking and to give more importance to existing nuances.