Community water content (CWC) was measured across the site in January 2008. Sponge cores, 2–3 cm diameter and 3 cm depth, were inserted into the moss beds adjacent to each quadrat, and were retrieved after 24 h. The sponges were placed in airtight tubes, returned to the laboratory within 1 h and weighed to determine fresh weight. The sponges were then left to dessicate in the laboratory, at a relative humidity of 22%, until a constant dry weight was reached. This method has been shown to give a good correlation with true turf water content while avoiding destructive analysis of the vegetation (Robinson and King unpublished data). The CWC was calculated as field wet weight − final dry weight / final dry weight