SEED BANK DYNAMICS - LONGEVITY, VIABILITY AND PREDATION OF SEEDS OF SEROTINOUS PLANTS IN THE CENTRAL NAMIB DESERT

Longevity, viability and predation of seeds were studied over 2 years in Aptosimum spinescens (Scrophulariaceae), Blepharis grossa (Acanthaceae), Geigeria alata, G. ornativa (Asteraceae), Petalidium setosum and P. variabile (Acanthaceae). The majority of seeds were stored on parent plants of the study species, apart from G. alata which showed a dimorphic seed dispersal mode. A decline in viability was found in two species (G. alata and G. ornativa) during the study period. Seed losses to Coleoptera and Diptera larvae ranged on average from 16% (P. setosum) to 25% (B. grossa). In this study the degree of serotiny was related to life form. Seed viability was related to seed characteristics rather than to the method of seed storage.