Pitfall traps were operated through a full year in nine habitats along a 200 m transect covering a variety of heathland and wetland vegetation types (Calluna, Erica, Empetrum, Molinia, Myrica, Salix, Carex, Phragmites). Principal Component Analysis and similarity indices distinguished two groups of spider communities, a heathland and a marsh community. Surprisingly, the fauna of the Molinia meadow belonged to the heathland type, in spite of higher habitat similarity with marshes. Neither vegetation structure, soil moisture or proximity in the habitat mosaic could explain the pattern of spider species composition.