GERMINATION ECOLOGY OF 6 SHRUBS IN FIRE-PRONE CAPE FYNBOS

To explain the recruitment and coexistence of species which establish after fire, this study predicted that each species would have differen t germination cues as a component of different regeneration niches. Fu rthermore, for species subject to natural fire frequencies of 10-20 ye ars, fire-related cues, seed dormancy, extended longevity and fire-rel ated germination cues might be predicted. However, results indicated b roadly similar germination requirements. Seeds subjected to two heat t reatments and a charcoal extract failed to show significantly enhanced germination. Instead, highest germination successes were achieved und er alternating diurnal temperatures which implied an indirect fire cue , viz. the removal of insulating vegetation. Leachate solution inhibit ed germination in two species suggesting allelopathic effects during i nter-fire periods. Only two species showed dormancy and three species did not have extended longevity but showed declining germinability aft er three years. Finally, in order to determine the potential germinati on from a soil-stored seed bank, data analysis simulated a seed bank c omprising three years' accumulation of seeds. In each species the prop ortion of germinable seeds varied each year over the three years. Also , the germinability in response to ageing varied for each year's seed production. This would explain the variation in densities of the six s pecies after different fire events, and hence offers a better explanat ion for species' coexistence.