THE EFFECTS OF GRAZING MANAGEMENT ON THE VEGETATION OF MESOTROPHIC (MEADOW) GRASSLAND IN NORTHERN ENGLAND

1. Haymeadows in the Yorkshire Dales and the North Pennines in Norther n England are grazed with cattle and sheep outside the 2-3-month summe r period, when a hay or silage crop is grown. Experimental exclosures were used from August 1987 to June 1991 to prevent this grazing for va rious periods in the year in a meadow at Ravenstonedale, Cumbria. Vege tation change was investigated using biomass samples taken in June of each year. 2. Experimental treatments were: (i) no grazing at any time of the year, (ii) no grazing from the time of the hay cut until 1 Jan uary; (iii) no grazing from 1 January to the time of the hay cut; (iv) control plots in which the normal grazing regime was followed each ye ar. All other management factors were kept constant. 3. All plots show ed vegetation changes related to treatment and to time. The main trend was the treatment effect, with the greatest reduction in species rich ness occurring in the ungrazed plots. Changes in the species compositi on of the plots were associated with species' strategies (sensu Grime 1979) in the established and regenerative phase. 4. The results are di scussed in the context of management designed to manipulate plant spec ies composition in old meadowland.