Co-Authors:
Thompson, S.E., UC Berkeley, Department of Civil and Environmental Engineering, 661 Davis Hall, Berkeley, CA, United States
Assouline, S., A R O - Volcani Center, Soil, Water and Environmental Sciences, Bet Dagan, Israel
Chen, L., Desert Research Center, Division of Hydrologic Sciences, Las Vegas, NV, United States
Trahktenbrot, A., Duke University, Nicholas School of the Environment, Box 90328, Durham, NC, United States
Svoray, T., Ben-Gurion University of the Negev, Geography and Environmental Development, Be'er Sheva, Israel
Katul, G.G., Duke University, Nicholas School of the Environment, Box 90328, Durham, NC, United States, Duke University, Pratt School of Engineering, Durham, NC, United States
Abstract:
Seed dispersal alters gene flow, reproduction, migration and ultimately spatial organization of dryland ecosystems. Because many seeds in drylands lack adaptations for long-distance dispersal, seed transport by secondary processes such as tumbling in the wind or mobilization in overland flow plays a dominant role in determining where seeds ultimately germinate. Here, recent developments in modeling runoff generation in spatially complex dryland ecosystems are reviewed with the aim of proposing improvements to mechanistic modeling of seed dispersal processes. The objective is to develop a physically-based yet operational framework for determining seed dispersal due to surface runoff, a process that has gained recent experimental attention. A Buoyant OBject Coupled Eulerian - Lagrangian Closure model (BOB-CELC) is proposed to represent seed movement in shallow surface flows. The BOB-CELC is then employed to investigate the sensitivity of seed transport to landscape and storm properties and to the spatial configuration of vegetation patches interspersed within bare earth. The potential to simplify seed transport outcomes by considering the limiting behavior of multiple runoff events is briefly considered, as is the potential for developing highly mechanistic, spatially explicit models that link seed transport, vegetation structure and water movement across multiple generations of dryland plants. © 2014 Thompson et al.; licensee BioMed Central Ltd.