Early seral communities in a limestone quarry: an experimental study of treatment effects on cover and richness of vegetation.
Oolitic limestone workings on the Leicestershire/Lincolnshire border were sown in 1981 with Brachypodium sylvaticum and Lotus corniculatus; in a factorial experiment fertilizer was applied as mixed powders of ammonium sulphate, triple superphosphate, potassium chloride and kieserite (2.1 g/m2 of N:P:K:Mg at 2:2:2:1), or plots were covered with wire netting to exclude rabbits. Percentage plant cover, spp. richness, rooted frequency and flowering were recorded between 1980 and 1983. Plant cover increased by up to 7 times when one or 2 of the treatments were applied, and by 15 times when all 3 were applied simultaneously, reaching 78% cover in 1984. The number of spp. in the whole experimental area increased from 46 in 1980 to 65 in 1984, and the mean number increased from 22 to 32/m2.