A STUDY OF SPECIES RICHNESS AND DIVERSITY IN SEED BANKS AND ITS USE FOR THE ENVIRONMENTAL MITIGATION OF A PROPOSED HOLIDAY VILLAGE DEVELOPMENT IN A CONIFERIZED WOODLAND IN SOUTH EAST ENGLAND

A survey was carried out to determine the density and species composit ion of germinable seed in the surface soil layers of 30 plots within a coniferized lowland woodland in East Kent in order to establish the r esources available for habitat creation in the event of some areas bei ng modified during a proposed holiday village development. The selecte d plots included conifer plantations (up to 69 years old), broad-leave d plantations and the semi-natural broad-leaved edges that remain on p arts of the perimeter of the site which were used as the control, A to tal of 13 682 seedlings emerged from the soil samples during the four- month germination trials, Fifty-two species were identified of which e ight were ancient woodland indicator species for south-east England, T he most abundant species represented in the seed banks were: Juncus ef fusus, Rubus fruticosus, Carer sylvatica, Betula pendula and Agrostis tenuis. Between-site comparisons of coniferous plots of different ages revealed a marked reduction in the seed species and seed density in p lantations over 65 years old, Results of soil nutrient and texture ana lyses ruled out the likelihood of edaphic factors being responsible fo r between-site differences in seed bank composition. Seed species rich ness and diversity (Shannon-Wiener diversity index) were greatest in t he semi-natural broad-leaved edges, but the diversity index used also showed that two replanted conifer sites had high values despite few sp ecies being present. The usefulness and limitations of diversity indic es in the context of seed bank studies is discussed. From the results of the study, management proposals for the site have been put forward in order to maintain floristic diversity and mitigate the impact of th e proposed development.