What was done
The Merkus pine (Pinus merkusii Jungh. et de Vriese) grows in scattered locations across southeast Asia and is the only species of pine that naturally occurs south of the equator.  In this study, the author used gas exchange and growth models - parameterized with empirical data - to simulate seedling responses to various climate change scenarios.

What was learned
A 2°C increase in air temperature, coupled with a prolonged dry season, reduced rates of gross photosynthesis and biomass production in Merkus pine tree seedlings by 8 and 59%, respectively.  However, under twice-ambient atmospheric CO2 concentrations, a 2°C rise in air temperature stimulated annual rates of gross photosynthesis and biomass production by 58 and 305%, respectively.  Moreover, when the prolonged dry season was added to the mix of changed environmental conditions, the seedlings still exhibited significant projected increases in photosynthesis and biomass production of 48 and 164%, respectively.

What it means
As the air's CO2 content increases in the future, Merkus pine tree seedlings will likely exhibit increased rates of photosynthesis and biomass production, even if ambient air temperatures rise and prolonged dry seasons develop.  The end result of these potential climatic changes would be a profound stimulus for enhanced growth and proliferation of this important Pinus species throughout southeast Asia.