PT Journal
AU OLIVEIRA, M
   MARENCO, R
TI Photosynthesis and biomass accumulation in Carapa surinamensis (Meliaceae) in response to water stress at ambient and elevated CO<sub>2</sub>
SO Photosynthetica
PY 2019
BP 137
EP 146
VL 57
IS 1
DI 10.32615/ps.2019.023
WP https://ps.ueb.cas.cz/artkey/phs-201901-0017.php
SN 03003604
AB Climate models predict an increase in atmospheric CO<sub>2</sub> concentration and prolonged droughts in some parts of the Amazon, but the effect of elevated CO<sub>2</sub> is still unknown. Two experiments (ambient CO<sub>2</sub> ‒ 400 ppm and elevated CO<sub>2</sub> ‒ 700 ppm) were conducted to assess the effect of drought (soil at 50% field capacity) on physiological parameters of Carapa. At ambient CO<sub>2</sub> concentration, light-saturated net photosynthetic rate (P<sub>Nsat</sub>) was reduced by 33.5% and stomatal conductance (g<sub>s</sub>) by 46.4% under drought, but the effect of drought on P<sub>Nsat</sub> and g<sub>s</sub> was nullified at elevated CO<sub>2</sub>. Total plant biomass and leaf area production were also reduced (42‒47%) by drought. By changing leaf traits, Carapa is able to endure drought, as the consumptive use of water was reduced under drought (32‒40%). The improvement of P<sub>Nsat</sub> under elevated CO<sub>2</sub> and water stress and the leaf plasticity of Carapa broaden our understanding of the physiology of Amazonian trees.
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