Impact of Increasing CO2 Levels on Mangifera indica Growth and Carbon Sequestration Potential at Different Nitrogen Addition levels

Abstract

The rapid increase in atmospheric CO2 concentrations, coupled with nitrogen enrichment in soils, necessitates a thorough examination of their effects on plant growth and carbon sequestration potential. This study carried out during 2018 to 2019 in the department of Environmental Sciences, Bharathiar University, investigates the influence of escalating CO2 levels on the growth metrics shoot length (SL), leaf length (LL), leaf width (LW), and carbon sequestration capabilities of Mangifera indica L. under varying nitrogen addition levels. We studied five CO2 conditions separately one after the other, including ambient (408 ppm) and elevated levels (450, 500, 550, and 600 ppm), using an OSC S-1000 L plant growth chamber, while nitrogen was supplied as potassium nitrate at rates of 0, 3, 6, 12, and 24 g N/m². Notably, plant carbon content peaked at 50.96 ± 0.092% (mean ± S.D.) at the highest nitrogen level under 600 ppm CO2. One-way ANOVA revealed significant variations (p < 0.0001) in carbon content across all CO2 conditions and nitrogen levels. Regression analysis demonstrated a positive correlation (p < 0.05) between CO2 conditions and plant growth parameters, including SL, LL, LW, and carbon content across all nitrogen levels. We conclude that both elevated CO2 and nitrogen addition significantly enhance the growth and carbon sequestration potential of Mangifera indica, highlighting the importance of strategic nutrient management in optimizing forest productivity under climate change.