Hydrologists and ecologists alike have often conceptualized transpiration and photosynthesis as depending on root-zone soil moisture, thereby neglecting the movement of water through the plant. But this movement is not instantaneous, and in reality these fluxes respond to the plant’s internal water status (often studied through water potential), which could be decoupled from soil moisture. We study – using remote sensing, models, and stand-scale data – how this flow of water through plants affects the dynamics of evapotranspiration and photosynthesis. Key themes in this research include the sensitivity of stomatal closure to vapor pressure deficit (which is expected to increase under future, hotter droughts) and the role of xylem and stomatal traits. As an example of the latter, we created the first global map of isohydricity, a measure of leaf water response to soil water stress.
Global ecosystem-scale plant hydraulic traits retrieved using model-data fusion
Liu, Y., N.M. Holtzman, and A.G. Konings (2021). Global ecosystem-scale plant hydraulic traits retrieved using model-data fusion. Hydrology and Earth System Science, 25:2399-2417.
L-band vegetation optical depth as an indicator of plant water potential in a temperate deciduous forest stand
N. Holtzman, L.D.L Anderegg, S. Kraatz, A. Mavrovic, O. Sonnentag, C. Pappas, M.H. Cosh, A. Langlois, T. Lakhankar, D. Tesser, N. Steiner, A. Colliander, A. Roy, and A.G. Konings (2021). L-band vegetation optical depth as an indicator of plant water potential in a temperate deciduous forest stand. Biogeosciences, 18:739-753.
Plant hydraulics accentuates the effect of atmospheric moisture stress on transpiration
Liu, Y., M. Kumar, G.G. Katul, X. Feng, and A.G. Konings (2020). Plant hydraulics enhances atmospheric moisture stress on transpiration. Nature Climate Change, 10:691-695.
Beyond soil water potential: An expanded view on isohydricity including land–atmosphere interactions and phenology
Novick, K. A., A.G. Konings, and P. Gentine (2019). Plant, Cell, and Environment, 42: 1802-1815.
Hydraulic diversity of forests regulates ecosystem resilience during drought
Anderegg, W.R.L., A.G. Konings, A.T. Trugman, K. Yu, D.R. Bowling, R. Gabbitas, D.S. Karp, S. Pacala, J.S. Sperry, B.N. Sulman, and N. Zenes (2018). Nature, 561: 538-541.
Global variations in ecosystem scale isohydricity
Konings, A. G. and P. Gentine (2017). Global Change Biology, 23 (2): 891-905.
Sensitivity of grassland productivity to aridity controlled by stomatal and xylem regulation
Konings, A. G., A.P. Williams, and P. Gentine (2017). Nature Geoscience, 10: 284-288.