Symposium 1: Biodiversity and Ecological Processes in Agroecosystems
Organized by: I Perfecto and A Power
Monday, August 4. 8:00 AM to 11:30 AM, SITCC Oglethorpe Auditorium.

Food web structure of the coffee agroforests: does biodiversity makes a difference?

Perfecto, Ivette*,1, Greenberg, Russell2, Ibarra-Nunez, Guillermo3, 1 University of Michigan, Ann Arbor, Michigan2 Smithsonian Migratory Bird Center, Washington, DC3 El Colegio de la Frontera Sur, Tapachula, Mexico

ABSTRACT- The coffee agroecosystem in Northern Latin America is characterized by a high floristic diversity. These agroforests serve as habitat for a high diversity and density of associated fauna, including many generalist predators. Does this diversity contributes to the reduction of insect herbivores, and therefore, to the productivity and sustainability of the agroecosystem? In our studies of the Mexican agroforests we examined the trophic relationships of bird, spiders, ants and herbivores. Through a series of exclosure experiments in coffee farms with different levels of shade and floristic diversity, we have identified the significant trophic interactions in this very diverse tropical agroecosystem. We will discuss the results from these experiments as well as the implications of these complex direct and indirect interactions on the productivity and sustainability of the coffee agroecosystem.

Key words: trophic interactions, insectivorous birds, food web, coffee agroecosystem