Towards a monitoring method and a number of multifaceted and hierarchical biodiversity indicators for urban and suburban parks

In this paper we develop a method for the general monitoring of the biodive rsity in (sub)urban parks. The method works along two lines, that of habita t diversity and that of species diversity. On the habitat level we measure the diversity in so called 'habitat units'. These units are divided in plan ar, linear and punctual elements. For each category we calculate a Shannon- Wiener diversity index and a saturation index. The latter is the ratio of t he diversity index compared to the maximum diversity possible. On the speci es level we use the species number and diversity index of vascular plants, as measured in random sampling plots of 100 m(2) (for trees and shrubs) and 4 m(2) (for herbaceous vegetation). In addition, we also use the species n umber of butterflies, amphibians and breeding birds. These numbers are comp ared with the total species number in Flanders, resulting in a saturation i ndex per park for butterflies, amphibians and breeding birds. In this way 2 0 biodiversity indicators are obtained. The proposed method was applied to the municipal park of Loppem (West-Flanders, Belgium), from which the neces sary time budget has been calculated. Since it is the first application of a new method and no reference to other parks is available, the proposed bio indicators have been compared with criteria given in the literature on the selection of biodiversity indicators. (C) 2000 Elsevier Science B.V. All ri ghts reserved.