AERIAL SEED BANKS IN THE CENTRAL NAMIB - DISTRIBUTION OF SEROTINOUS PLANTS IN RELATION TO CLIMATE AND HABITAT

Distribution of serotinous plants in the central Namib and adjacent areas was correlated with climatic parameters rain quantity, variability and frequency and prevailing (type of precipitation) and habitat in a Binary Multiple Regression model. The desert fringe with (a) high variability of rain (60-70% of annual mean), (b) low quantities of rain (50-100 mmyr-1), and (c) prevailing precipitation type rain rather than fog, proved most conducive to serotiny. Serotinous plants were most common in habitats where run-off accumulated, such as foothills of mountains, pans and channels, and on plains. Temporal and spatial variation of water availability, as well as intense rains and run-off, both inducing seed dispersal by water, might explain the abundance of serotinous plants at the desert fringe.