Changes in Predispersal Seed Predation Levels after Fire for Two Australian Legumes, Acacia Elongata and Sphaerolobium Vimineum

Publisher Website
Google Scholar
Abstract
Predispersal seed predation was estimated before and for 2-3 yr after a single fire for two legume species. The relationship between this seed predation and the build-up of a buried seedbank for future seedling recruitment was assessd. For Acacia elongata Sieb. ex DC, loss of seed was mainly due to a weevil, Melanterius acaciae Lea (Coleoptera: Curculionidae). There was no evidence of decline in the intensity of this predation following the fire. However, the large initial seed-crop after the fire may have satiated the available seed predators. Predispersal seed predators destroyed some 97% of the second fruit-crop produced after the fire, limiting the build-up of a buried seed bank. For Sphaerolobium vimineum Sm., loss of seed was due to two species of Eurytoma (Hymenoptera: Eurytomidae). There was no seed predation in the first seed-crop after the fire, perhaps because the seed predators were unable to locate the host population. However, in the second seed-crop after fire, the intensity of seed predation returned to the pre-burn level. In this species, seed production was high in all sampled years and the build-up of the buried seed bank after the fire was ensured, even in the presence of Eurytoma.