Publications [#259991] of James F. Reynolds

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Papers Published

  1. Ogle, K; REYNOLDS, JF, Desert dogma revisited: coupling of stomatal conductance and photosyntesis in the desert shrub, Larrea tridentata, Plant, Cell and Enviroment, vol. 25 no. 7 (2002), pp. 909-921, WILEY [doi] .
    (last updated on 2023/06/01)

    Abstract:
    The success of the desert shrub Larrea tridentata (creosotebush) has been largely attributed to temperature acclimation and stomatal control of photosynthesis (A) under drought stress. However, there is a paucity of field data on these relationships. To address this void, we conducted a joint field and modelling study that encompassed a diverse set of environmental conditions. At a Larrea-dominated site in southern New Mexico we manipulated soil moisture during the growing season over a 2-year period and measured plant pre-dawn water potential (Ψpd), stomatal conductance (g) and A of individual shrubs. We used these data to develop a semi-mechanistic photosynthesis model (A-Season) that explicitly couples internal CO2 (Ci) and g. Vapour pressure deficit (VPD) and Ψpd affect instantaneous g in a manner that is consistent with a biophysical model of stomatal regulation of leaf water potential. Ci is modelled as a function of g, derived from a simplification of a typical A-Ci curve. After incorporating the effects of growing temperature on stomatal behaviour, the model was able to capture the large diurnal fluctuations in A, g and Ci and the observed hysteresis in g versus Ci dynamics. Our field data and application of the A-Season model suggest that dogma attributed to Larrea's success is supported with regard to stomatal responses to VPD and Ψpd, but not for mechanisms of temperature acclimation and CO2 demand.