HR: 14:30h
AN: H43I-04    [Abstracts]
TI: Spatial organisation of vegetation in water controlled landscapes: the role of vegetation dispersion strategies.
AU: * Thompson, S E
EM: set8@duke.edu
AF: Nicholas School of the Environment and Earth Sciences, Duke University, Box 90328 Duke University, Durham, NC 27708, United States
AU: Katul, G
EM: gaby@duke.edu
AF: Nicholas School of the Environment and Earth Sciences, Duke University, Box 90328 Duke University, Durham, NC 27708, United States
AB: When investigating the spatial organization of biomass resulting from plant-water feedbacks in arid ecosystems, spatial movement of plants is generally represented as a diffusive processes. Diffusive representations of plant movement have two consequences: they fix the length scale of dispersion to the immediate vicinity of the parent plant, and thus cannot explicitly represent long distance dispersal; and they treat the local gradient of biomass as the determinant of the rate and direction of dispersal. An adaptation of an existing model (Rietkerk et al. 2002) is used to investigate the significance of these assumptions on predicted spatial distributions of vegetation. Model runs were conducted separately with a diffusive and a long-distance dispersive kernel for spatial movement and the resulting spatial organization of vegetation was contrasted. The results indicate that dispersion behavior strongly influences the spatial organization of vegetation in arid landscapes, destabilizing the regular spatial patterns often predicted by models utilizing diffusive representations of biomass movement. The model results provide insight into ecological hypotheses regarding the preponderance of short-range dispersion behavior observed in arid ecosystems, and suggest that this is a consequence of the highly organized nature of the soil water resource. Rietkerk, M., M. C. Boerlijst, F. van Langevelde, R. HilleRisLambers, J. van de Koppel, L. Kumar, H. H. T. Prins, and A. M. de Roos. 2002. Self-organization of vegetation in arid ecosystems. American Naturalist 160:524-530.
DE: 1813 Eco-hydrology
SC: Hydrology [H]
MN: 2007 Fall Meeting