Plant-Vertebrate Seed Dispersal Systems in the Mediterranean: Ecological, Evolutionary, and Historical Determinants

Investigations vertebrate seed dispersal systems in the Mediterranean show that extremely efficient plant-disperser mutualisms donot require, and thus are not evidence for, mutual evolutionary adjustments of participants. Current Mediterranean dispersal systems have apparently been shaped by means of 1. trophic and behavioral daptations of birds morphologically preadapted to pre-existing plant resources, and 2. disperser-mediated processes of habitatshaping occurring at an ecological time scale. These processes depend on differential recruitment of plant species as a function fdisperser preferences, rather than on adjustments based on evolutionary processes. On the plant side, there is a prevalence of historical nd phylogenetic effects, which reflects a series of ecological limitations inherent tothe interactions between plants and dispersal gents that constrain plant adaptation todispersers. To test adaptive hypotheses and explanations, future investigations Mediterranean plant-disperser systems should concentrate more on the animal than on the plant side of the interaction.