RABBIT GRAZING, PLANT COMPETITION AND SEEDLING RECRUITMENT IN ACID GRASSLAND

Oryctolagus cuniculus grazing affected the stature and composition of the grassland throughout the year. Species that increased in cover in rabbit-grazed grassland included the grass Anthoxanthum odoratum and the forb Rumex acetosella. Species that decreased included the grasses Festuca rubra and Agrostis capillaris and the forbs Vicia sativa and Trifolium repens. There was negligible change in the total number of plant species with grazing. The seed bank under the acid grassland was extremely heterogeneous. Eight of the 23 commonest ruderal species beneath acid grassland decreased in cover significantly (eg Capsella bursa-pastoris and Papaver dubium); none increased significantly. Most of the ruderal species in the seed bank of nearby arable soils increased under grazing. Most plant species on cultivated grassland soils regenerated from vegetative fragments (eg Holcus mollis, Stellaria graminea, Rumex acetosa and R. acetosella), rather than by germination of seed. Regrowth shoots outnumbered seedlings by a factor of 1.3-23.3. -from Author