PARENT SESSION
Poster Session 1 / Sesion Carteles 1: Invasive Species / Invasivas
Tuesday, January 10 / Martes, 10 de Enero, 6:00 - 7:30 pm, Salon Yucatan, Lobby Level, Fiesta Americana
Trophic dynamics in urban communities.
Faeth, StanLey*,1, Marussich, Wendy2, 1 Arizona State University, Tempe, USA2 University of Arizona, Tucson, USA
ABSTRACT- Human activities dramatically change abundances, diversity, and composition of species. However, little is known about how the most intense human activity, urbanization, alters food webs and trophic structure in biological communities. Experimental studies of arthropod communities in the Phoenix, Arizonaarea, situated amid the Sonoran Desert, reveal some surprising alterations in control of trophic dynamics. Species composition is radically altered and resource subsidies and environmental changes shift seasonality and increase and stabilize plant productivity. In contrast to outlying deserts where limiting resources dominate, predation by birds becomes the dominant force controlling arthropods on urban plants. Reduced predation risk elevates abundances and alters foraging behavior of birds such that urban birds exert increased top-down effects on arthropods in urban habitats. Shifts in control of food web dynamics are likely common in urban ecosystems, and are influenced by complex human social processes ad feedbacks.
SPANISH ABSTRACT- .