Regeneration of Agathis australis and associated species in a native bush stand on Limestone Downs

Abstract

A predator-proof fence enclosing 270 m2 of predominantly kauri (Agathis australis) bush on Limestone Downs was erected in February 2004. Regeneration of A. australis and other seed-dispersed species was monitored in permanent quadrats laid out within and immediately outside the enclosure. The quantity of viable A. australis seed entering the enclosure by natural dispersal and extent of viable A. australis seed within the soil seed bank were measured. Two thirds of the viable seed dispersed was lost, probably through mammalian predation. Eleven species were found in the soil seed bank. No viable A. australis seed was found in the soil seed bank. Seed rain was the source of viable A. australis seed. Regeneration of A. australis was greater within the protected environment of the predator-proof fence. There was a decline in seedling numbers between May 2007 and April 2008 both inside and outside the predator-proof fence suggesting that predation was not the only factor influencing seedling survival. Keywords: Agathis australis, Xcluderâ„¢ fence, seed predation, seedling survival, regeneration, seed rain