PARENT SESSION
Tuesday, August 8, 8:00-11:30 am
Symposium 4 - Ecological and evolutionary processes in complex networks
Cotton Row, Mezzanine Level, Cook Convention Center
Organized by: TH Keitt (tkeitt@mail.utexas.edu) and B Fagan

The symposium addresses the structure and dynamics of ecological networks ranging from food webs to epidemiology to landscapes.

Plant-animal coevolutionary networks.

Bascompte, Jordi^*,1, ¹ Estación Biológica de Doñana, CSIC, Sevilla, Spain

ABSTRACT- The mutualistic interactions between plants and the animals that pollinate them or disperse their fruits have molded the organization of biodiversity on Earths. While the bulk of studies on mutualistic interactions have focused on highly specialized, pairwise interactions, there is almost no information on how mutualistic interactions are shaped in species-rich communities. I will review recent research aimed at filling this gap by using tools and concepts from the theory on complex networks. These results unambiguously conclude that mutualistic networks are highly heterogeneous (the bulk of species have a few interactions, but a few species have many more interactions than expected by chance); nested (specialists interact with proper subsets of the species generalists interact with); and asymmetric (if, for example, a plant species interacts strongly with an animal species, the animal interacts weakly with the plant). Networks of mutualistic interactions are thus neither randomly assembled nor organized in compartments arising from tight, parallel specialization. The reported network structure has far-reaching consequences for species persistence and coevolution.

Key words: complex networks, pollination, seed dispersal