PARENT SESSION
Symposium 16: Incorporating trophic diversity into the biodiversity-ecosystem functioning debate: Lessons from aquatic ecosystems
Organized by: P McIntyre, K France, JE Duffy, and AS Flecker
Thursday, August 11, 8:00 AM - 11:30 AM, Meeting Room 517 A, Level 5, Palais des congrès de Montréal

New theoretical approaches to biodiversity and ecosystem functioning in food webs.

Loreau, Michel¹, ¹ Laboratoire d'Ecologie, 75230 Paris Cedex 05, France

ABSTRACT- The consequences of biodiversity loss for ecosystem functioning and ecosystem services have aroused considerable interest during the last decade. Recent work, however, has mainly focused on the impact of species diversity within single trophic levels, both experimentally and theoretically. An important current challenge is to understand how species interactions affect the relationship between biodiversity and ecosystem functioning in complex food webs. In contrast to previous studies focusing on single trophic levels, recent theoretical work on multitrophic systems has shown that changes in biodiversity can lead to complex, nonlinear changes in ecosystem processes. Food-web structure - in particular the nature of population controls (top-down vs. bottom-up), food-web connectivity, and trade-offs among traits that determine species interaction strength - appears to profoundly influence ecosystem properties. Despite this complexity, however, biodiversity should still act as biological insurance for ecosystem processes, except when mean trophic interaction strength increases strongly with diversity.

Key words: Biodiversity, Ecosystem functioning, Food webs