Optimization of climatic factors for photosynthesis to address climate change challenges using the RSM technique

Climate change is significantly affecting the photosynthesis of mangrove plants. The effects of climatic factors, namely the elevated carbon dioxide (CO2) concentration, air temperature, and water regime on the photosynthetic of mangrove (Rhizophora apiculata), were investigated through physiological properties by using Response Surface Methodology (RSM) analysis for selecting tree species adaptive to climate change. The seedlings were grown in environment-controlled growth chambers with seven combinations of various CO2 concentrations and different temperatures. Each group has had four boxes at multiple water levels and salinity for almost three months. The DoE program was employed to find the effects and interactions between climatic factors. After 35 to 40 days of growth, the R. apiculata plant recorded optimum photosynthesis of CO2 at 525 ppm and the temperature at 32-34°C. Also, when the water level rises, R. apiculata's photosynthesis increases gradually, but it decreases gradually when the salt concentration rises. These results suggest that the low level of photosynthetic capacity may be attributed to the decreased CO2 fixative reaction system rather than the photochemical reaction system.