The impact of Rhinanthus spp. on sward productivity and composition: Implications for the restoration of species-rich grasslands Original Research Article

The impact of parasitic angiosperms of the genus Rhinanthus on grassland productivity and floristic composition was monitored at five sites in Britain and N. Italy. A combination of non-intervention and perturbation studies were used to detect differences in the yield and community composition of swards in the presence and absence of Rhinanthus spp. Productivity was found to be consistently lower in areas where Rhinanthus was present. The degree of suppression ranged between 8 and 73%, and was found to be positively correlated with site productivity. Community composition differed significantly between parasite infected and uninfected regions of the sward, the most notable differences being a decline in the proportion of grasses, and a concomitant increase in the proportion of dicotyledons, in the presence of the parasite. The results are discussed in relation to the use of Rhinanthus spp. as management tools for the restoration of species-rich grasslands. The practicalities associated with this option are considered.