The Bryophyte flora of Scanian sand-steppe vegetation and its relation to soil pH and phosphate availability

The sand-steppe is a vegetation type mainly found in the southern Baltic region on calcareous sand dominated by vascular plants such as Koeleria glauca, Dianthus arenarius ssp. arenarius and Astragalus arenarius. Eighty-eight plots representing most sand-steppe sites in Scania, southernmost Sweden, were analyzed with respect to bryophytes, pH and exchangeable phosphate in the topsoil. The most common species were Syntrichia ruraliformis, Hypnum lacunosum, Ceratodon purpureus, Brachythecium albicans, Bryum argenteum, Syntrichia ruralis and Racomitrium canescens, but several rare or red-listed taxa were also found. Total species richness was reduced in plots with subneutral topsoil but uniformly high in plots with alkaline topsoil. In these latter, however, concentrations of exchangeable phosphate were found to have a major effect on the bryophyte flora. A significant negative relationship between total species richness and phosphate concentrations was found and most rare species were restricted to, or most frequent in plots with low phosphate availability. Only a few common generalist taxa appeared favoured by high phosphate availability. These findings suggest that management intended to conserve the sand-steppe vegetation should be designed to keep availability of phosphate low. Mechanical soil disturbance should be favoured over heavy grazing and burning.