Controlled grazing studies on Nardus grassland: effects of between-tussock sward height and species of grazer on Nardus utilization and floristic composition in two fields in Scotland

Maintain upland heath/moorland

A small study of acid grassland with 10-15% matgrass Nardus stricta cover over 4.5 years in Scotland (Grant et al. 1996b) found an increase in use of matgrass by goats as the height of preferred between-tussock grasses decreased. Utilization declined over successive seasons under sheep grazing but was sustained by goat grazing. Matgrass growth rates were reduced as grazing severity increased, being lowest on the plot grazed to 4-5 cm by goats and highest on the 6-7 cm goat plot. Goats grazed more matgrass at 4.5 and 5.5 cm than the sheep did at 4.5 cm. The four treatments (each 0.15 ha) were between-tussock grasses maintained at 4-5 cm, 5-6 cm and 6-7 cm by goats or a sheep control at 4-5 cm. Matgrass utilization was estimated by the proportion of grazed stems (tillers) and leaves and grazing severity sampled by measuring 20-40 random leaf lengths of grazed leaves in July and October 1984-1987. Leaf growth was sampled on 30 stems/plot at weekly intervals from April-September 1988. Vegetation composition was recorded in May 1989 using an inclined point quadrat.