SUCCESSION FROM HEATHER MOORLAND TO BIRCH WOODLAND .2. GROWTH AND COMPETITION BETWEEN VACCINIUM-MYRTILLUS, DESCHAMPSIA-FLEXUOSA AND AGROSTIS-CAPILLARIS

(1) Vaccinium myrtillus, Deschampsia flexuosa and Agrostis capillaris are often successive dominants during succession from heather moorland to mature birch woodland. The effects of changes in light intensity and nutrient availability on the growth of and competition between these species are examined. (2) All species showed reduced growth when shaded, Vaccinium myrtillus was the least affected. (3) Both Deschampsia flexuosa and Agrostis capillaris showed strong positive growth responses to fertilizer addition, particularly in increased light. Vaccinium myrtillus showed a limited positive response. (4) Agrostis capillaris showed consistent competitive dominance over Deschampsia flexuosa, which showed consistent competitive dominance over Vaccinium myrtillus. (5) The results suggest that the timing of establishment of these species may be particularly important in determining their role in the succession from heather moorland to mature birch woodland.