Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

The effects of spatial variation in sheep grazing on Calluna vulgaris / Molinia caerulea interactions (old BD0126) - BD1218

Previous research has indicated that seasonal grazing of Molinia caerulea by sheep, following burning, can have a significant effect on its growth; the magnitude of the effect is influenced by both season and level of grass utilisation. In this study, existing species data on M.caerulea and Calluna vulgaris will be used to develop a predictive model of M. caerulea/C. vulgaris interactions in order to analyse effects of grazing and burning on the balance of these 2 species in moorland plant communities.

The study will be composed of 6 specific objectives outlined as follows, together with ways in which they might be achieved: 1. Use of a cellular automata model to explore spatial variation in vegetation occurrence and utilisation. Species dominance data from previous studies will be used to establish replacement trends for C. vulgaris and M. caerulea within the model - such trends will allow for variation in grazing level and occurrence of burning; 2. Evaluation of the probability of temporal variation in replacement of Calluna by Molinia (or vice versa) during 3 different grazing and burning regimes; 3. Quantification of the rate and direction of plant community change (NVC communities and individual C. vulgaris and M. caerulea species) across 100 ha of mixed moorland, using an existing NVC plant community model; 4. Quantification of spatial variation in Calluna/Molinia utilisation by sheep across 100 ha of mixed moorland, using the same grid of quadrats as in plant community assessments; 5. Use of the spatial model to assess significance of variation of Calluna/Molinia utilisation by sheep on rate of heather recovery across moorland, with predictions of species replacement and change being tested against field data; and 6. Effects of introducing heather burning on vegetation utilisation and recovery for both grazed and ungrazed areas. Field data on vegetation recovery across moorland following burning will be tested against predicted patterns of vegetation change to identify appropriate grazing and burning management scenarios for enhancing moorland vegetation recovery.
Project Documents
• Executive Summary : The effects of spatial variation in sheep grazing on Calluna vulgaris / Molinia caerulea interactions (old BD0126)   (58k)
Time-Scale and Cost
From: 1998

To: 2001

Cost: £141,651
Contractor / Funded Organisations
Fields of Study
Environmental Stewardship