In Luxembourg, as a consequence of land use intensification, there are only few relicts of nutrient-poor wetland habitats with a high conservation value left. Up to now, a small-scale spatial analysis of the relationships between soil factors and vegetation has not been published for these relicts. For this reason, we assessed vegetation composition, vegetation structure (90% percentile of the vegetation height, litter cover), soil variables relevant for plant nutrition (pH value, contents of phosphorous, potassium, calcium, magnesium) and Ellenberg indicator values (EIV-N, EIV-F) in five fen complexes in Luxembourg. The central questions were: Which environmental gradients explain the obvious zonation patterns (core and fringe zones) and which habitat qualities correlate with the number of threatened plant species? Therefore, in total, 74 small-sized quadrats were established in both core and fringe zones and vegetation and soil samples were analyzed. The quadrats differed clearly in soil pH value across ...