Growth dynamics and physiological response of selected forestry species to CO2 enriched atmosphere

Abstract

Terminalia arjtma, Terminalia bellirica and Terminalia chebula are important medicinal plants and part of Triphala, there is less study about the adaptation and mitigation of these species to elevated CO2. This study is helpful to understand about the adaptive and miligative and biochemical efficiency of these plants. Under elevated these three species are showed a belter response in elevated CO2 SOOppm over ambient 400ppm. The plant height, leaf length and width, stem diameter, number leaves and branches, root length, are higher in elevated SOOppm CO2 over ambient 400ppm as well as the biochemical properties like total chlorophyll and carotenoids, ascorbic acid, protein, proline, total sugar are increased dramatically at SOOppm over 400ppm. The photos>Tithetic rate was higher in elevated CO:in all seasons (winter, spring, and summer), stomatal conductance was higher in SOOppm spring and lower at summer. The intercellular CO2 concentration was higher in plants grown in SOOppm T.chebula in winter in the summer season. Transpiration rate was higher in winter and reduced over ambient in summer. Night respiration is less in T.arjuna compared to ambient, and there is a fluctuation concerning seasonality and species. Carbon sequestration, carbon partitioning, carbon mitigation and carbon stocks are high in elevated CO2 growing plants except for T.bellirica. Organic carbon was higher in elevated CO2 than ambient. Potassium, phosphorous and total nitrogen they with species and change in concentration according to elevated CO2. The plants grown in elevated CO2 are healthier than ambient condition and increases the health-promoting characters. These species are more adaptive and show mitigation efficiency and good biochemical efficiency. In future more studies needed to know about the response of plants towards elevated CO2.