Year Established: 2014 Start Date: 2014-03-01 End Date: 2015-02-28
Total Federal Funds: $25,000 Total Non-Federal Funds: $50,282
Principal Investigators: Chris Zou, Garey Fox, Rodney Will
Abstract: Most studies of land conversion to bioenergy production have focused solely on surface water and not groundwater. Changes in land use and vegetation cover can directly alter groundwater recharge processes, especially in water limited semi-arid and subhumid regions. Vegetation reduces groundwater recharge by either extracting groundwater from the saturated zone or reducing rainfall reaching the groundwater table. Research so far has focused mainly on the riparian zone where connectivity between the surface and the alluvial aquifer is intuitive and the interaction can be rapid. However, over 90% of land surface is upland, and the effect on groundwater of changes in upland vegetation cover such as conversion from redcedar woodland to herbaceous biofuel feedstock production is poorly understood. Special situation – OSU is receiving a USDA NIFA grant to understand how a cellulosic-based biofuel industry in Oklahoma will affect water resources, requiring baseline information of upland recharge before land conversion, i.e., redcedar removal and switchgrass planting. This creates an opportunity to conduct a standalone, one-year project of surface water and groundwater interaction under different vegetation types by strategically leveraging expertise associated with the USDA NIFA project. Data collected from native prairie, redcedar woodland, and post oak forest before manipulation will add to our understanding of how vegetation type affects the groundwater recharge and provide necessary preliminary data for understanding the effects of future land cover manipulation on groundwater resources. The proposed project will be a one-year, collaborative research effort between the Department of Natural Resource Ecology and Management, the Department of Biosystems and Agricultural Engineering, and the Department of Geology at Oklahoma State University. The overall objective is to quantitatively assess the effects of vegetation types on groundwater recharge in upland ecosystems. The proposed project will be a field-based experiment conducted at the Oklahoma State University Range Research Station (OSURRS). i). We will measure rooting zone soil moisture using electrical resistivity imaging (ERI); ii). We will install and instrument groundwater wells under each vegetation type to monitor groundwater levels, temperature, δO18 composition, and their seasonal fluctuations; iii). We will analyze soil core samples from the well drilling using chloride mass balance method to evaluate the long-term water flux in and out of the rooting zone associated with different vegetation cover at OSURRS. Results will be immediately available for land managers to make informed land management decisions to sustain groundwater resources; Results will directly contribute to a recently funded USDA NIFA water sustainability grant to OSU and an NSF EPSCoR project in Oklahoma; Understanding rooting zone soil water and groundwater are critical for adapting land management to increasing climate variability and drought frequency for water resource management and long-term planning.