THE IMPACT OF RHINANTHUS SPP ON SWARD PRODUCTIVITY AND COMPOSITION - IMPLICATIONS FOR THE RESTORATION OF SPECIES-RICH GRASSLANDS

The impact of parasitic angiosperms of the genus Rhinanthus on grassla nd productivity and floristic composition was monitored at five sites in Britain and N. Italy. A combination of non-intervention and perturb ation studies were used to detect differences in the yield and communi ty composition of swards in the presence and absence of Rhinanthus spp . Productivity was found to be consistently lower in areas where Rhina nthus was present. The degree of suppression ranged between 8 and 73%, and was found to be positively correlated with site productivity. Com munity composition differed significantly between parasite infected an d 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 r esults are discussed in relation to the use of Rhinanthus spp. as mana gement tools for the restoration of species-rich grasslands. The pract icalities associated with this option are considered. (C) 1997 Elsevie r Science Ltd.