Heathland Seedbanks under BrackenPteridium aquilinum(L.) Kuhn and their Importance for Re-vegetation after Bracken Control

In Great Britain, the regeneration of heathland and moorland plant communities after bracken control is slow and variable. Successful restoration depends on the availability of seed and the provision of suitable regeneration niches, as well as on the expansion of the plants previously present underneath the bracken canopy. This study investigates the availability of the seed resource of heathland species and its distribution, both in relation to increasing time since bracken invasion and with respect to its presence in litter or mineral soil.Calluna vulgariswas found to be the predominant species that germinated from the soil and litter beneath bracken at the sites studied. It appeared in greatest numbers from samples taken outside and at the edge of the bracken patch; numbers decreased deeper into the patch. Land which has been under bracken for a considerable period (>50 years) is likely to have a very reduced seedbank so that some form of propagule introduction, as well as litter disturbance, may be needed to speed up regeneration. On sites which have been invaded by bracken more recently, it is likely that litter incorporation into the soil would conserve the seed resource, whereas burning or litter removal would remove a significant proportion of that seed resource.