PARENT SESSION
Symposium #29: Scaling the implications of organismal size across evolutionary time and ecological space: A synthesis of recent advances and insights..
Organized by: BJ Enquist, F Smith, and PA Marquet
Thursday, August 8. 1:00 PM to 3:45 PM. Crystal Ballroom, TCC.
Plant allometry: Implications for ecology and evolution.
Enquist, Brian*,1, Niklas, Karl2, 1 University of Arizona, Tucson, AZ2 Cornell University, Ithaca, NY
ABSTRACT- One of the central problems facing biology is to mechanistically link organismal, community, and ecosystem attributes across spatial and temporal scales. Here we assess recent extensions of allometric theory for plants against a growing worldwide database highlighting variation in biomass, growth, production, abundance, and diversity for individuals across a diverse suite of woody plant communities. We show how a general allometric framework can predict intra- and interspecific scaling relationships among seed plant leaf, stem, and root biomass. These scaling rules define the boundary conditions for above- and below-ground biomass partitioning and the production of biomass in general. Analyses of the relationship between density and plant size across a global sample of plant communities indicates that the constraints of allometry at the level of the individual ramify to influence community size distributions. Allometric theory is shown to provide a robust framework by which to then quantify the relationships among tree size frequency distributions, standing biomass, species number, and number of individuals per unit area. Evidence is given that similar scaling relationships hold in paleo communities. The model thus identifies and defines the limits to the diversification of seed plant biomass allocation strategies and provides a mechanistic foundation for scaling from cells to ecosystems. More importantly our results suggest many macroecological properties emerge from a few allometric principles operating at the level of the individual.
KEY WORDS: Plant Allometry, Scaling, Macroecology, Biomass production