GRAZING AND VEGETATION CHANGE - DEFLECTED OR MODIFIED SUCCESSION

1. Vegetation change during the first 6 years of a controlled grazing experiment on calcareous former arable land was estimated using permanent quadrats. The results are compared with similar data from older patches of grassland nearby. 2. The relative effects of time, place, sheep grazing and season of grazing on community change were assessed by canonical community analysis: detailed responses of the commoner species were investigated by analysis of variance. The two approaches complemented each other; multivariate analysis clearly separated effects on the community scale but was weak at detecting complex interactions. 3. Grazing deflected succession (sensu Godwin 1929), but was subordinate to an intrinsic rate of vegetation change and to local variations in its direction. Succession only moved immediately towards the composition of the local ancient grasslands under the heaviest grazing treatment. 4. Irrespective of grazing treatment and local conditions, secondary succession towards species-rich calcicolous grassland appears to take at least a century to run its course. Thus, grazed grassland and forest successions can operate over similar time-scales. 5. The implications for countryside management and 'creative conservation' are discussed.