Context  Flood disturbances act as strong filters on arthropod communities by excluding species that are not adapted to the high water-tables. Sensitive species can survive in these areas by either migrating to more terrestrial habitats or by using dry refuges within the wetland created by topographical heterogeneity.

Objectives  We examined the role of dry refugia and the scale at which these affect arthropod densities, mainly cursorial species, by using previous information on local dryness-wetness of wetlands.

Methods  We selected sites wiith different flooding regimes within a large fen based on used prior information on local dryness-wetness of wetlands at 2 × 2 m resolution. We then used suction sampling to collect abundance data of beetles and spiders, and related these data to flooding regimes at spatial scales up to 26 × 26 m.

Results  These studies indicated that species within Linyphiidae, Staphylinidae and Chrysomelidae were more abundant in the presence of dry refuges at a scale of 10 × 10 m, whereas Salticidae preferred wetter areas. Species within Carabidae, Lycosidae and a number of other taxon groups were indifferent to these structures. Moreover, the data seem to suggest that mainly habitat generalists benefit from the refuges. Accordingly, those groups that were impartial to the dry refuges included almost exclusively species that can be categorised as wetland specialists.

Conclusions  Small-scale refuges in heterogeneously flooded wetlands may be important to consider for guiding contemporary efforts to restore wetlands as a mean to promote biodiversity.