Breitburg, D. L. The Academy of Natural Sciences, Breit@acnatsci.org
Sanders, J. G. The Academy of Natural Sciences, Jsanders@acnatsci.org
FOOD WEB COMPLEXITY AND THE RESPONSE OF AQUATIC SYSTEMS TO STRESS
Understanding how the complexity of food webs affects responses of aquatic systems is critical to both our basic understanding of the ecology of these systems and to determining the necessary complexity of experimental food webs to generate information for sound management decisions. As part of the COASTES program we have been conducting a series of 1 m3 mesocosm, large field enclosure, and small-scale laboratory experiments to examine how trophic complexity affects the response of a representative coastal system, the Patuxent River, to nutrient enrichment and trace elements.
Our results indicate that the effect of increasing food chain length can be quite different than the effect of increasing the number of species that feed at the same trophic level. Thus the geometry of food webs as well as diversity of species within an assemblage is important. For example, increasing food chain length increased the magnitude of the response of phytoplankton to nutrient additions while increasing the number and kinds of taxa feeding on phytoplankton dampened the absolute and proportional response. The effect of food web complexity on responses to stressors also varied among stressors and was independent of the strength of the direct effects of consumers on prey.
Day: Thursday, Feb. 4
Time: 03:45 - 04:00pm
Location: Hilton of Santa Fe