A restoration experiment on moorland infested by Pteridium aquilinum: Plant species responses

A long-term vegetation restoration experiment on land infested by Pteridium aquilinum is described. It was established in 1993 in the North Peak Environmentally Sensitive Area, Derbyshire, UK. The target was to restore Calluna moorland that existed before P. aquilinum invasion. The experimental design incorporated vegetation restoration treatments (sheep grazing and Calluna vulgaris seeding) at split-plot levels within P. aquilinum control treatments (herbicide and cutting in different combinations). For P. aquilinum the most successful control treatment used was cutting twice per year. August cover was reduced from ca. 100% to <10% in most years from 1998. C. vulgaris seeding was most successful using C. vulgaris brash, with a mean density of 2.5 seedling m−2 recorded. Species richness was greatest with cutting-only treatments, giving a species density of 7–8 m−2 from 1998, compared to about 3 m−2 for untreated plots. Grazing gave 6–7 m−2 compared to 4–5 m−2 for un-grazed plots. Controlling P. aquilinum was found to be a long-term commitment. Cutting-twice-per-year with light grazing is recommended, both for P. aquilinum control and vegetation restoration.