More Like this

1. Detecting long‐term changes in stomatal conductance: challenges and opportunities of tree‐ring δ18O proxy

   https://doi.org/10.1111/nph.18430  

   Guerrieri, Rossella ; Belmecheri, Soumaya ; Asbjornsen, Heidi ; Xiao, Jingfeng ; Hollinger, David Y. ; Clark, Kenneth ; Jennings, Katie ; Kolb, Thomas E. ; Munger, J. William ; Richardson, Andrew D. ; et al ( November 2022 , New Phytologist)
2. Climate and stomatal traits drive covariation in nighttime stomatal conductance and daytime gas exchange rates in a widespread C 4 grass

   https://doi.org/10.1111/nph.16987  

   Chieppa, Jeff ; Brown, Tia ; Giresi, Presley ; Juenger, Thomas E. ; Resco de Dios, Víctor ; Tissue, David T. ; Aspinwall, Michael J. ( February 2021 , New Phytologist)
3. Aquaporin regulation in roots controls plant hydraulic conductance, stomatal conductance, and leaf water potential in Pinus radiata under water stress

   https://doi.org/10.1111/pce.13460  

   Rodríguez‐Gamir, Juan ; Xue, Jianming ; Clearwater, Michael J. ; Meason, Dean F. ; Clinton, Peter W. ; Domec, Jean‐Christophe ( November 2018 , Plant, Cell & Environment)

   Stomatal regulation is crucial for forest species performance and survival on drought‐prone sites. We investigated the regulation of root and shoot hydraulics in threePinus radiataclones exposed to drought stress and its coordination with stomatal conductance (g_s) and leaf water potential (Ψ_leaf). All clones experienced a substantial decrease in root‐specific root hydraulic conductance (K_root‐r) in response to the water stress, but leaf‐specific shoot hydraulic conductance (K_shoot‐l) did not change in any of the clones. The reduction inK_root‐rcaused a decrease in leaf‐specific whole‐plant hydraulic conductance (K_plant‐l). Among clones, the larger the decrease inK_plant‐l, the more stomata closed in response to drought. Rewatering resulted in a quick recovery ofK_root‐randg_s. Our results demonstrated that the reduction inK_plant‐l, attributed to a down regulation of aquaporin activity in roots, was linked to the isohydric stomatal behaviour, resulting in a nearly constant Ψ_leafas water stress started. We concluded that higherK_plant‐lis associated with water stress resistance by sustaining a less negative Ψ_leafand delaying stomatal closure.

    

   more » « less
4. Disentangling the role of photosynthesis and stomatal conductance on rising forest water-use efficiency

   https://doi.org/10.1073/pnas.1905912116  

   Guerrieri, Rossella ; Belmecheri, Soumaya ; Ollinger, Scott V. ; Asbjornsen, Heidi ; Jennings, Katie ; Xiao, Jingfeng ; Stocker, Benjamin D. ; Martin, Mary ; Hollinger, David Y. ; Bracho-Garrillo, Rosvel ; et al ( August 2019 , Proceedings of the National Academy of Sciences)

   Multiple lines of evidence suggest that plant water-use efficiency (WUE)—the ratio of carbon assimilation to water loss—has increased in recent decades. Although rising atmospheric CO 2 has been proposed as the principal cause, the underlying physiological mechanisms are still being debated, and implications for the global water cycle remain uncertain. Here, we addressed this gap using 30-y tree ring records of carbon and oxygen isotope measurements and basal area increment from 12 species in 8 North American mature temperate forests. Our goal was to separate the contributions of enhanced photosynthesis and reduced stomatal conductance to WUE trends and to assess consistency between multiple commonly used methods for estimating WUE. Our results show that tree ring-derived estimates of increases in WUE are consistent with estimates from atmospheric measurements and predictions based on an optimal balancing of carbon gains and water costs, but are lower than those based on ecosystem-scale flux observations. Although both physiological mechanisms contributed to rising WUE, enhanced photosynthesis was widespread, while reductions in stomatal conductance were modest and restricted to species that experienced moisture limitations. This finding challenges the hypothesis that rising WUE in forests is primarily the result of widespread, CO 2 -induced reductions in stomatal conductance. 

   more » « less
5. Explainable machine learning for predicting stomatal conductance across multiple plant functional types

   https://doi.org/10.1016/j.agrformet.2024.109955  

   Gaur, Srishti ; Drewry, Darren T. ( May 2024 , Agricultural and Forest Meteorology)