Is there allelopathic self-inhibition of generative regeneration within Widdringtonia cedarbergensis stands?

Abstract

Widdringtonia cedarbergensis seeds sown in pots with soil collected under fynbos had a mean germination of 48,16%. Mean germination was 6,0% in pots on soil collected under adult Widdringtonia cedarbergensis with the cedar litter left intact or scraped off. Germination was 49% in pots on cedar soil with the litter burnt off. These results suggest that cedar litter under mature canopies inhibits germination, and that the inhibiting factor was removed by fire. Field data, however, showed no difference in the occurrence of seedlings on burnt or unburnt areas, although higher seedling numbers were associated with burnt parent canopies.