PT  - JOURNAL ARTICLE
AU  - OLIVEIRA, M.F.
AU  - MARENCO, R.A.
TI  - Photosynthesis and biomass accumulation in Carapa surinamensis (Meliaceae) in response to water stress at ambient and elevated CO&lt;sub&gt;2&lt;/sub&gt;
DP  - 2019 Jan 30
TA  - Photosynthetica
PG  - 137--146
VI  - 57
IP  - 1
AID - 10.32615/ps.2019.023
IS  - 03003604
AB  - Climate models predict an increase in atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentration and prolonged droughts in some parts of the Amazon, but the effect of elevated CO&lt;sub&gt;2&lt;/sub&gt; is still unknown. Two experiments (ambient CO&lt;sub&gt;2&lt;/sub&gt; ‒ 400 ppm and elevated CO&lt;sub&gt;2&lt;/sub&gt; ‒ 700 ppm) were conducted to assess the effect of drought (soil at 50% field capacity) on physiological parameters of Carapa. At ambient CO&lt;sub&gt;2&lt;/sub&gt; concentration, light-saturated net photosynthetic rate (P&lt;sub&gt;Nsat&lt;/sub&gt;) was reduced by 33.5% and stomatal conductance (g&lt;sub&gt;s&lt;/sub&gt;) by 46.4% under drought, but the effect of drought on P&lt;sub&gt;Nsat&lt;/sub&gt; and g&lt;sub&gt;s&lt;/sub&gt; was nullified at elevated CO&lt;sub&gt;2&lt;/sub&gt;. 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&lt;sub&gt;Nsat&lt;/sub&gt; under elevated CO&lt;sub&gt;2&lt;/sub&gt; and water stress and the leaf plasticity of Carapa broaden our understanding of the physiology of Amazonian trees.