Seed Bank Divergence Between Arctostaphylos Adans. (Ericaceae) and Ceanothus L. (Rhamnaceae) Suggests Different Seed Predator Interactions

Abstract

Two of the dominant shrub genera in California chaparral, Arctostaphylos and Ceanothus, utilize persistent soil seed banks for post-fire recovery of their populations. Seed production and seed rain is subject to considerable predation by the animal community. These genera differ significantly in their seed size, and contrary to seed bank theory, Arctostaphylos with the larger seeds are able to accumulate substantially larger seed banks. Literature and field data are used to propose a model to account for these differences in seed bank densities, specifically, that the animal community involved in seed predation differs between the two genera.