Changes in the quantity and quality of grassland due to winter grazing by brent geese (Branta bernicla)

Brent geese grazing on Lolium/Agrostis grassland on the coast of north Norfolk had a diet which largely reflected the species composition of the sward. Grazing led to reductions of 72% (1988) and 49% (1989) in the biomass of grass and a 20% decrease (1989) in the percentage of live grass in the sward by the end of the winter. During the time between the last grazing by the geese (early March) and the introduction of livestock (May), the difference in the percentage of live grass between previously grazed and ungrazed plots became undetectable and the difference in biomass was reduced from 49 to 21%.