Linking root water uptake to root traits, and assessing performance of common models.
Neutron imaging is used to measure soil water movement and water uptake by individual roots in situ.
Root water uptake can be linked to characteristic root traits, such as diameter or age. Comparing actual water uptake with modeled water uptake highlights problems with current model assumptions. This work points to the need for new research to understand soil hydraulic properties with and without roots present.
Knowledge of plant root function is largely based on indirect measurements of bulk soil water or nutrient extraction, which limits modeling of root function in land surface models. Neutron radiography, complementary to X-ray imaging, was used to assess in situ water uptake from newer, finer roots and older, thicker roots of a poplar seedling growing in sand. The smaller diameter roots had greater water uptake per unit surface area than the larger diameter roots, ranging from 0.0027-0.0116 g/cm2 root surface area/h. Model analysis based on root-free soil hydraulic properties indicated unreasonably large water fluxes between the vertical soil layers during the first 16 hours after wetting — suggesting problems with common soil hydraulic or root surface area modeling approaches, and the need to further research and understand the impacts of roots on soil hydraulic properties.
Jeffrey M. Warren
Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory email@example.com (865-241-3150)
Laboratory Directed Research and Development Program at Oak Ridge National Laboratory (ORNL); DOE, Office of Science, Office of Biological and Environmental Research, Office of Workforce Development for Teachers and Scientists and Office of Science Graduate Student Research (SCGSR) program; High Flux Isotope Reactor, a DOE Office of Science User Facility operated by ORNL
Dhiman, I., H. Bilheux, K. DeCarlo, S.L. Painter, L. Santodonato, J.M. Warren. 2017. “Quantifying Root Water Extraction After Drought Recovery Using Sub-mm In Situ Empirical Data,” Plant and Soil. DOI: 10.1007/s11104-017-3408-5.
SC-23.1 Climate and Environmental Sciences Division, BER
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]
List all highlights (possible long download time)