MITIGATING CARBON DIOXIDE EMISSION USING NINETEEN TREE SPECIES IN THE GREENBELTS OF CEMENT FACTORIES IN EGYPT

The cement industry is responsible for approximately 8% of planet-warming carbon dioxide emissions.Establishing greenbelts around cement industrial areas may be an effective strategy to reduce atmospheric CO2 pollution.Thus, the main objective of this study is to identify high-performing tree species in carbon sequestration under ambient and elevated carbon dioxide conditions to be used for mitigating cement pollution in Egypt.Hence, we chose 19 tree species for this purpose.The CO2 response curves (A/Ci response curves) and leaf gas exchange parameters of each tree species were measured using a portable photosynthesis system (LCpro-SD).Rubisco activity and electron transport chain activity were calculated for each tree species.At CO2 concentration up to 800 ppm, only six species exhibited tight relationships between photosynthetic rate and intercellular CO2 (Ci): Conocarpus lancifolius, Delonix regia, Populus alba, Dalbergia sissoo, and Ficus infectoria and Senna surattense.The total stomatal conductance was elevated in D. sissoo, D. regia, and Morus alba.While, Azadirachta indica and P. alba showed the highest water-use efficiency at the same conditions.The highest Rubisco activity (45.6 to 43.5 mol m -2 s -1 ) was recorded at 800 ppm CO2 for P. alba, Duranta erecta, D. regia, S. surattensis, S. sesban, and F. infectoria.Accordingly, we recommend the cultivation of D. regia and P. alba in the greenbelts of the cement factories and urban areas to sequester more CO2, and help in mitigating the impact of climate change.More research is advised under field-scale validation or long-term monitoring in local environmental circumstances.