Mound plantation as an effective climate change adaptation and mitigation measure: Evaluation of the growth in the Chittagong coastal forest division of Bangladesh

Abstract

Afforestation/reforestation can mitigate global climate change at low costs by reducing atmospheric carbon. The coastal plantations can act for both climate change mitigation and adaptation apart from protecting coastal people from sea-born calamities. In the global sea-level rise scenario, experimenting with the growth of the non-mangrove tree species in the coastal saline soil is a distinctive approach to observe the effects of salinity on the non-mangrove trees. The present study conducted such an experiment, species planted in the saline soil's mound in the Kattoli forest beat under the Chittagong coastal forest division for four non-mangrove tree species, i.e., Acacia auriculiformis, Casuarina equisetifolia, Samanea saman, and Terminalia arjuna. The study evaluated their growth performance and carbon sequestration potential by comparing them with the embankment plantation of the same tree species. The stem density was the highest, 2651 ± 174 per ha in the embankment, and the lowest, 1536 ± 101 per ha in the m15-16 mound plantation. Considering all the tree species, the highest biomass growth including aboveground and belowground, 195.44 ± 21.91 t ha−1, and the total biomass's net MAI, 21.46 ± 2.81 t ha−1yr−1, was in the embankment among the given sites. Accordingly, the embankment shows the highest sequestration of carbon in the biomass, including aboveground and belowground, 97.72 ± 10.96 tC ha−1, and the m15-16 site shows the lowest, 17.64 ± 2.90 tC ha−1. The highest salinity, 8.73 ± 1.30 mS/m, was in the m14-15 site and the lowest, 1.43 ± 0.41, was in the embankment. The study concludes that salinity ranging from 1.91 mS/m to 16.52 mS/m can support the selected trees to grow. It was evident that the non-mangrove tree species' growth was retarded by the ebb and tide and salinity of the soil. The study is expected to be helpful to climate change mitigation and adaptation practitioners in Bangladesh.