HR: 1340h
AN: H33A-1375    [Abstracts]
TI: Modeling Microbial Growth Dynamics, Patterns, and Coexistence on Partially Saturated Rough Surfaces
AU: * Long, T
EM: tal03005@engr.uconn.edu
AF: Dept. of Civil and Environmental Engineering, University of Connecticut, 266 Glenbrook Rd, Storrs, CT 06269 United States
AU: Or, D
EM: dani.or@epfl.ch
AF: School of Architecture, Civil, and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Bâtiment GR, Station 2, Lausanne, CH-1015 Switzerland
AB: A new modeling tool was developed to study the impact of variations in matric potential on aquatic pathways and substrate diffusion, and on microbial growth and movement on unsaturated rough surfaces. The modeling domain is composed of prescribed distributions of conical pits (sites) connected by prismatic channels (bonds) representing rough surfaces of soils or rocks. The well-defined geometry facilitates exact description of aqueous phase distribution within the roughness for a given matric potential. Microbial growth within the resulting highly variable diffusion network architectures (vary with matric potential) and interactions with nutrient diffusion patterns are simulated by coupling Reaction-Diffusion Method (RDM) and the Active Walker Method (AWM). Simulation results show direct impact of wetness conditions (matric potential values) on microbial growth rates and expansion patters for the same surface roughness. In addition to modification of mean diffusion rates for drier or wetter conditions, the network connectivity may induce significant changes in spatial patters of microbial growth. Impact of these changes on coexistence of two competing microbial species will be discussed.
DE: 0466 Modeling
DE: 1875 Vadose zone
DE: 4840 Microbiology and microbial ecology (0465)
SC: Hydrology [H]
MN: Fall Meeting 2005