HR: 11:05h
AN: H52B-04    [Abstracts]
TI: Wind-Dispersion of Biomass in Patterned Vegetation Models: From Classical Diffusion to WALD
AU: * Thompson, S E
EM: set8@duke.edu
AF: Nicholas School of Environment and Earth Sciences, Duke University, Durham, NC 27701, United States
AU: Katul, G G
EM: gaby@duke.edu
AF: Nicholas School of Environment and Earth Sciences, Duke University, Durham, NC 27701, United States
AB: Vegetation spatial patterning observed in semi-arid and arid ecosystems worldwide provides an exciting system for the testing and validation of ecohydrological models that couple the evolution of the vegetation pattern to the hydrological regime. However, one fundamental limitation to these models is their represention of biomass dispersion, currently assumed to follow a classical diffusion processes with an empirical diffusion coefficient. We present a new approach for biomass movement based upon the WALD model, a mechanistic dispersal kernel for wind-dispersed seeds. The model can be parameterised based upon seed characteristics, release height, and the mean wind frequency distribution. The WALD model is shown to reproduce the velocities of biomass movement reconstructed from the pollen record to within an order of magnitude or better for a wide range of species considered in North America and Europe. Incorporating WALD in pattern-forming ecohydrological models is briefly discussed.
DE: 1809 Desertification
DE: 1813 Eco-hydrology
DE: 1847 Modeling
SC: Hydrology [H]
MN: 2007 Joint Assembly