PARENT SESSION
Oral Session #77: Biodiversity and Ecosystem Function II.
Presiding: G. Chong
Thursday, August 8. 9:00 AM to 11:30 AM. Coconino Meeting Room, TCC.
Life history diversity of tropical tree species and its consequences for community structure and dynamics.
MULLER-LANDAU, HELENE*,1, WRIGHT, S. JOSEPH2, HUBBELL, STEPHEN2,3, CONDIT, RICHARD2, FOSTER, ROBIN4, 1 National Center for Ecological Analysis and Synthesis, Santa Barbara, CA2 Smithsonian Tropical Research Institute, Balboa, Panama, PANAMA3 Department of Botany, Athens, GA4 Field Museum, Chicago, IL
ABSTRACT- We document patterns of interspecific variation in life history traits among a set of coexisting tropical tree species and investigate the consequences of different aspects of this variation for species diversity and ecosystem properties.Trade-offs between traits contribute to diversity maintenance via life history niche differentiation, and the array of functional and life history traits found among tree species in a community strongly affects ecosystem properties such as successional patterns of biomass accumulation and resilience to disturbance. Using data from Barro Colorado Island, Panama, we examine patterns of interspecific variation and covariation in life history traits including seed production, seed dispersal, growth in different light environments, survival at different growth rates, and mature height. Interspecific variation in these traits falls largely along a few principal components axes, each of which relates to a particular life history trade-off. We use maximum likelihood methods to fit the distribution of species in the full trait space. To assess the importance of each trade-off and the corresponding life-history variation, we use a spatially-explicit, individual-based forest simulator to simulate forest dynamics with and without variation along each axis. We find that each trade-off contributes to diversity maintenance, and that variation along each axis has a distinct impact on ecosystem properties.
KEY WORDS: life history trade-offs, succession, diversity maintenance, tropical forest