Relationships between soil characteristics and species richness in two botanically heterogeneous created meadows in the urban English West Midlands

Understanding the relationship between soil fertility and species richness in mesotrophic meadows is important for the conservation of species-rich grassland and particularly for habitat creation. This relationship was investigated in surveys of two heterogeneous created meadows. Redundancy analyses of species abundance data and related soil parameters (extractable phosphorus and extractable potassium, mineral nitrogen, pH, loss-on-ignition, texture and moisture) indicated that phosphorus and potassium concentrations separately accounted for most variation in species composition at the different meadows. Contrary to expectation, low potassium was associated with low diversity, although low phosphorus was associated with high diversity. The concentration ranges in the optimal stands most closely related to species richness are: <7 mg extractable P 100 g(-1) (Truog's extraction) and 10-30 mg extractable K 100 g(-1). These ranges are expected to be useful in evaluating soil nutrient status prior to habitat creation. (C) 2000 Elsevier Science Ltd. All rights reserved.