Abstract. In a small alluvial floodplain depression (21 ha) of the river Dijle, a selection of 56 characteristic, mainly groundwater-depending plant species was mapped using a regular 20 by 20 m square cell mapping grid. In order to understand the spatial distribution of the plant species and their vegetation types, several environmental variables, including groundwater regime, groundwater chemistry, soil texture, soil chemical composition and management type were measured in detail.
Using Detrended Correspondence Analysis and Canonical Detrended Correspondence Analysis, the relation between these environmental variables and the plant species and vegetation types, respectively, is described in detail. Management type and groundwater fluctuations are recognized as the two main sets of environmental variables causing the specific spatial distribution of plant species and vegetation types for the mire-ecosystem of the silty alluvial floodplain.