Evaluation of Carbon Sequestration Potential of Different Melia Germplasms in Eastern Dry Zone of Karnataka, India

Abstract

Melia dubia is one of the best agroforestry tree species, which is known for its faster growth rate and biomass accumulation. To maintain ecological balance and sustainability carbon sequestration plays an important role, hence this study aimed at identifying the best suitable Melia germplasm for Eastern dry zone of Karnataka. The present research was conducted from April, 2023 to July, 2024 in Agroforestry field unit, University of Agricultural Sciences, Bangalore. Randomized block design was used for the experiment. Evaluation of 15 Melia germplasms revealed that highest tree height was recorded in MD-173 (16.06 m) and lowest in MD-129 (12.31 m). Girth at breast height (GBH) was highest in MTP-3 (97.94 cm) and lowest in MD-135 (60.35 cm). Tree volume was highest in MTP-3 (328.6 m3 ha-1) and was on par with MTP-1 (314.4 m3 ha-1) and MD-138 (307.4 m3 ha-1) whereas, significantly lower tree volume was found in MD-135 (106.0 m3 ha-1). The above ground biomass, belowground biomass, total biomass and total biomass carbon were found highest in MTP-3 (197.2 t ha-1, 51.3 t ha-1, 248.6 t ha-1 and 124.2 t ha-1 respectively), and significantly lowest were found in MD-135 (63.6 t ha-1, 16.5 t ha-1, 80.1 t ha-1 and 40.1 t ha-1 respectively). MTP-3 consistently exhibited the highest biomass CO₂ values across all intervals, reaching a remarkable 455.9 t ha⁻¹ at 81 months followed by MTP-1 (436.1 t ha⁻1). MD-138 (426.4 t ha⁻¹), MD-157 (375.9 t ha⁻¹), and MD-164 (375.7 t ha⁻¹) were found to be intermediate CO2 accumulators. Lowest carbon sequestration potential was found in MD-135 (147.1 t ha-1), MD-174 (209.8 t ha-1) and MD-129 (236.3 t ha-1). MTP-3 followed by MTP-1 and MD-138 were more suitable for Eastern dry zone of Karnataka.