115-2 Effect of Desiccation Induced Shrinkage On Meadow Water Holding Capacity.



Monday, October 17, 2011: 1:20 PM
Henry Gonzalez Convention Center, Room 217C, Concourse Level

Chelsea Arnold1, Asmeret A. Berhe2 and Teamrat A. Ghezzehei1, (1)School of Natural Sciences, University of California, Merced, Merced, CA
(2)University of California, Merced, Merced, CA
Resiliency of high elevation wet meadows to a fluctuating water table is a function of the historic hydrologic conditions in the meadow that influence the processes of soil consolidation and oxidation of organic matter. These two processes can have a profound impact on the overall water holding capacity of meadows. The process of soil consolidation is instantaneous and irreversible as the pore structure is permanently altered, whereas the process of oxidation of organic matter is reversible over the longer term if water levels are restored within the meadow.  Within the historic range of water level in a meadow, we hypothesize that a meadow will retain its functioning and resiliency as long as carbon inputs remain constant.  However, if the water table drops below a historic level, due to climate change and/or management practices, the two processes of soil consolidation and oxidation of organic matter will influence the resiliency of the meadow through a decrease in porosity and an increase in bulk density, in both the saturated and unsaturated zones, influencing the overall water holding capacity of the meadow.
See more from this Division: S01 Soil Physics
See more from this Session: Micro- and Macro-Scale Water Dynamics In Unsaturated Soil Mechanics and Porous Media