Effect of physiographic type and harvesting age on biomass yield, chemical composition, and carbon sequestration of mangrove plantations for biofuel feedstock production

Abstract

Many coastal communities of SE-Asia, including Thailand have managed mangrove forests for charcoal production. However, understanding and managing the harvesting age of mangrove plantations in different ecotypes is limited for sustainable biofuel production. Therefore, the objectives of this research were to determine the effect of physiographic type and harvesting age on the biomass yield, chemical composition, CO2 adsorption of aboveground mangrove biomass. The data were collected during 2018–2019 from two geographical types including the riverine and basin mangrove plantations in Samut-Songkhram, Thailand. The experimental plots were selected at different ages (5, 10, and 15 years). The riverine mangrove forest had higher dry aboveground woody biomass, calorific value, and CO2 adsorption than did the basin mangrove forest. For both mangrove ecotypes, there were no significant differences in chemical elements. Extending harvesting age from 5 to 15 years tended to increase the woody biomass yield and quality, and CO2 adsorption of mangrove forests. With increasing harvesting age, the dry aboveground woody biomass, calorific value, and CO2 adsorption of mangroves increased 34.4–283.9 t ha−1, 3841.1- 3924.9 kcal kg−1, and 55.6–453.4 t CO2 ha−1, respectively, but ash and N content decreased 4.8–3.4% and 0.2–0.1%, respectively. Compared with other ages, extending harvest until 15 years yielded the highest potential biomass for biofuel feedstock production and carbon sequestration in both mangrove ecotypes.