The optimum temperature for photosynthetic CO2 assimilation of A. mangium phyllodes was 30-32 °C. Photosystem 2 (PS 2) exhibited high tolerance to high temperature. Gas exchange and the function of PS2 of A. mangium were adapted to the temperature regime of the tropical environment and this might be the contributing factor to their fast growth under tropical conditions. and Hua Yu, Bee-Lian Ong.