HR: 0800h
AN: PP51C-0615    [Abstracts]
TI: Importance of Soil Texture in Paleo-Vegetation Modeling Studies
AU: * Shellito, C J
EM: lucinda.shellito@unco.edu
AF: University of Northern Colorado, Earth Sciences Program, Campus Box 100, Greeley, CO 80639 United States
AU: Clifthorne, S
EM: sarahc@pmc.ucsc.edu
AF: Earth Sciences Department, University of California, Santa Cruz, 1156 High St., Santa Cruz, CA 95064 United States
AU: Sloan, L C
EM: lcsloan@pmc.ucsc.edu
AF: Earth Sciences Department, University of California, Santa Cruz, 1156 High St., Santa Cruz, CA 95064 United States
AU: Kueppers, L
EM: kueppers@pmc.ucsc.edu
AF: Earth Sciences Department, University of California, Santa Cruz, 1156 High St., Santa Cruz, CA 95064 United States
AB: The utility of a dynamic global vegetation model (DGVM) depends on the accuracy of the background climatology driving the model and the boundary conditions. In this study, we examine the sensitivity of the NCAR LSM-DGVM to one aspect of the boundary condition, the global soil texture. Soil texture is a critical factor influencing the availability of soil moisture. Available soil moisture will generally determine the dominant vegetation in a region, and, both soil moisture and vegetation will have important feedbacks on climate. Most paleoclimate modeling studies incorporate a globally uniform soil texture due to a lack of a global datasets regarding paleosol types. This becomes problematic when trying to address questions regarding potential changes in the global ecosystem due to a change in climate because the influence of soil texture on equilibrium vegetation in a DGVM experiment may be as large as other climatic forcing factors in a given region. In this study, we consider the effect of soil texture on the distribution of global vegetation in an Early Eocene DGVM study. We generate a global distribution of clay abundances using annual averaged temperatures and precipitation estimates from previous Eocene modeling studies. In all previous Eocene climate modeling studies, clay is specified at globally uniform value of 18%. In our new Eocene soil distribution, clay percentages vary from near zero to 80%. We incorporate the new soil scheme into the surface boundary conditions for a DGVM experiment. As model output demonstrates, the clay has a pronounced impact on soil moisture, which has a strong impact on the presence and abundance of plant functional types in the model.
DE: 4914 Continental climate records
DE: 4928 Global climate models (1626, 3337)
DE: 4950 Paleoecology
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005