Net greenhouse gas balance of fiber wood plantation on peat in Indonesia

Tropical peatlands cycle and store large amounts of carbon in their soil and biomass¹^-⁵. Climate and land-use change alter greenhouse gas fluxes of tropical peatlands, but the magnitude of these changes remains highly uncertain⁶^-¹⁹. Here we measure net ecosystem exchanges of carbon dioxide, methane, and soil nitrous oxide fluxes between October 2016 - May 2022 from <em>Acacia</em> <em>crassicarpa</em> plantation, degraded forest and intact forest within the same peat landscape, representing land-cover change trajectories in Sumatra, Indonesia. This allows us to present a full plantation rotation greenhouse gas flux balance in fiber wood plantation on peatland. We find that the <em>Acacia</em> plantation has lower greenhouse gas emissions than the degraded site with a similar average groundwater level, despite more intensive land-use. The greenhouse gas emissions from the <em>Acacia</em> plantation over a full plantation rotation (35.2 ± 4.7 tCO₂-eq ha⁻¹ yr⁻¹, average ± standard deviation) were around two times higher than those from the intact forest (20.3 ± 3.7 tCO₂-eq ha⁻¹ yr⁻¹), but only half of the current IPCC Tier 1 emission factor²⁰ for this land-use. Our results can help to reduce the uncertainty in greenhouse gas emissions estimates, provide an estimate of the impact of land-use change on tropical peat, and develop science-based peatland management practices as nature-based climate solutions.