Vadose‐zone soil moisture is an important driver of processes in agricultural, hydrological, ecological, and climate systems, yet the detailed nature of plant water use across ranges of scales is often poorly characterized. With projected changes in climate and land use (including afforestation, urbanization, agricultural intensification, and biofuels production) there is a critical need to understand the likely impacts on the hydrologic cycle and ecosystem health. Important hydrological and biophysical processes are not adequately characterized with point estimates, and models of rootwater uptake are generally unable to accurately predict such changes. Our objectives are to: 1) quantify multi‐scale dynamics of vegetation‐water interactions across different land cover types to improve predictive capabilities of hydrologic models, and 2) explore the impacts of land use and climate changes on watershed‐ to Great Lakes Basin‐scale hydrologic fluxes.
To explore the likely effects of projected changes in climate and land cover, we propose to use time‐lapse electrical resistivity imaging and a novel coupling of a fully integrated terrestrial hydrology model with a dynamic vegetation growth model to study managed and natural sites along a climate gradient across a range of soils. The intellectual merit of this research includes 1) improved knowledge and predictive capability of short‐ and long‐term processes that drive the terrestrial water cycle, 2) root‐zone moisture and root‐development data that will improve parameterization of roots in coupled land surface and climate models, and 3) quantitative information about implications of land use and climate changes across a range of scales.
Our work also has several significant broader impacts. First, the analysis will provide a critical foundation for further exploration of the impacts of biofuel crop development and reforestation for energy independence and carbon sequestration initiatives. Second, we are developing novel tools to image transient moisture under a range of land uses and climate conditions, and predict the impacts of climate and land use changes on the terrestrial hydrologic cycle. Third, the developed tools would increase the efficiency of resource allocation for monitoring natural and managed systems by practitioners in agriculture, ecology, and hydrology. Fourth, this project will advance discovery and understanding while promoting teaching, training and learning through an ongoing study of the impact of undergraduate research experiences. Finally, findings of the proposed work will be highlighted by existing outreach programs, and ultimately may play a pivotal role in policy decisions regarding the environmental sustainability of the various land management options.