Seed Dynamics in Calluna-Arctostaphylos Heath in North-Eastern Scotland

(1) Estimates were made of seed production, dispersal and storage in the soil in Calluna-Arctostaphylos heath in N.E. Scotland. Germination and seedling establishment in recently burned areas were also studied. (2) Seed production and dispersal by individual species were found to follow the abundance of the species in each stand, though the performance of some species declined as the Calluna canopy closed. Little seed input occurred from surrounding areas into closed or recently burned stands. (3) The amount of seed stored in the soil varied according to stand age. Seeds of Calluna vulgaris and Carexpilulifera increased in abundance with stand age. Stored seed of most other species decreased in numbers though in some there was a slight increase in the degenerate Calluna vulgaris phase. (4) The number of seedlings establishing after fire was far fewer than would be expected from the soil seed store, and is correlated with the type of substrate left by the fire. (5) Seed budgets are estimated for a 15 year fire rotation for the major species studied.