Comparing seed removal of 16 pine species differing in invasiveness

Abstract

Small seed mass is regarded as a robust trait related to invasion success, especially in pines. However, few studies have explored whether inva- siveness related to small seed mass is also associated to low levels of seed predation in the recipient commu- nity. We conducted field cafeteria seed removal experiments comparing 16 Pinus species that differ in seed mass to test if seed removal might impose biotic resistance to Pinus spp. and if there are differences between species related to seed mass. Seeds were removed rapidly and in high proportion. In the Mediterranean shrublands, where the experiments were conducted, rodents and ants were the main seed removers. Mean seed survival time was significantly different between species. However, smaller seeds were not the most predated. Our study suggests that, in pine species with high invasiveness, the potential higher seed removal of small seeds can be counterbal- anced by larger seed crops