Assessing the potential of compaction techniques in tropical peatlands for effective carbon reduction and climate change mitigation

Abstract

There is a pressing need to tackle carbon emissions from oil palm plantations on tropical peatland, which has garnered significant discussion and concern in recent years. In response, compaction techniques were introduced in Malaysia with the aim of mitigating CO2 emissions by improving moisture levels and reducing soil aeration. This research investigates the impact of mechanical compaction on two distinct ecosystems: a peat swamp forest (PSF) and an oil palm plantation (OPP), characterized by their unique physicochemical properties Using a specially designed compaction apparatus, significant changes in carbon emissions were observed in PSF but not in OPP, with means 1263 and 404 mg CO2-eq m−2 h−1, respectively. This disparity can be due to substrate availability between the two ecosystems. Subsequently, in the PSF, a promising pattern of a percentage ratio of approximately 1:3.5 was observed, indicating a substantial reduction in CO2 emissions (from 1295 to 468 mg m−2 h−1; 64%) alongside a corresponding increase in CH4 emissions (from −50 to 60 µg m−2 h−1; 221%). This finding suggests that compaction alters the aerobic peat horizon, bringing the peat surface closer to the groundwater level. The study underscores the importance of considering confounding factors such as decomposition degree and groundwater fluctuation when assessing the effects of compaction on tropical peat. By shedding light on these complexities, the findings contribute to a better understanding of the efficacy of compaction techniques in reducing emissions of these special case atmospheric pollutants.