Pre-dispersal seed removal of fleshy fruits and Quercus coccifera (Fagaceae) acorns in a recently burned Mediterranean habitat.

Abstract

Pre-dispersal seed removal of fleshy fruits and Quercus coccifera (Fagaceae) acorns in a recently burned Mediterranean habitat. The seed fate in early successional habitats can determine plant composition and regeneration capacity after disturbance. Pre-dispersal seed removal has been poorly studied in Mediterranean habitats, especially in burned and logged habitats. We assessed it for two years in pine forests with experiments excluding vertebrates from fleshy fruits (infructescences of Smilax aspera and Rubia peregrina) and acorns (branches of Quercus coccifera). We compared one unburned and one burned area (control). Acorn removal was nil in the burned area while in the unburned habitat seed removal occurred from the beginning of the experiments. It is suggested that the greater vegetation cover in the unburned area shelter rodents from predators and increased their activity. In contrast, reduced cover in the burned area and the occurrence of gnawed acorns on the ground suggest acorn removal by rodents mainly in the post-dispersive stage. Smilax aspera seed removal was slower, and total loss of fruits due to senescence higher, in the burned area. Seed removal appears to be conditioned by interannual variations related to the activity and density of granivores and frugivores, the availability of fleshy fruits, and the maturation of fruits. In post-fire managed areas the role of granivores and frugivores in the regeneration process should be taken into account.