Pattern and process in South Coast dune fynbos : population, community and landscape level studies

Abstract

The study aimed to explain vegetation dynamics in response to disturbance in a dune landscape comprising a mosaic and admixture of grassland, fynbos and thicket. A hierarchical approach directed investigations at the landscape, community and population levels, with emphasis on seed banks. The study concentrated on fynbos, the predominant vegetation type. At the landscape-level, pattern was attributed to successional processes rather than abiotic factors. Each vegetation was maintained under defined disturbance regimes of fire, grazing and bushcutting. In the absence of disturbance, succession proceeded from grassland, through fynbos, to thicket. The study contributed to existing theory on the effects of disturbance on seed bank size, and the relationship between seed bank composition and its above-ground vegetation. No single model for successional pathways and mechanisms was supported: these differed amongst vegetation types and within fynbos communities.