Work

Soil respiration and litterfall dynamics along a forest-to-oil palm plantation transition in an Indonesian peatland

Year: 2026

Type: article

Abstract: Poor understanding of biogeochemical processes driving variation in soil CO 2 emissions in tropical peatlands limits model capacity to predict the large and growing contribution of peatland disturbance to human-induced GHG emissions. We measured monthly soil total (SR) and heterotrophic (SRh) respiration, concurrently with environmental variables, over 2 years (2012 – 2013) in a primary swamp forest (PF), a drained logged forest (DF) and a 7-year-old oil palm plantation (OP) in a Sumatran peatland. Monthly litterfall was monitored in the forests and litter decomposition rates were assessed at all sites over a period of 250 days. Annual C outputs from SRh (Mg C ha −1 yr −1 ) were substantially elevated in the disturbed sites (13.7 ± 0.2 in the DF, and 23.6 ± 0.3 and 24.3 ± 0.3 in the OP, with and without drainage canals, respectively) compared to the PF (9.9 ± 0.2). SRh rates rose with increasing disturbance intensity as micro-climatic conditions became drier and warmer. The estimated pruned frond input in the OP (2.1 ± 0.2 Mg C ha −1 yr −1 ) was less than half the measured litterfall rates in the forests (4.8 ± 0.4 and 4.2 ± 0.3 Mg C ha −1 yr −1 in the PF and DF, respectively). Furthermore, litter decomposition (d -1 ) was higher in the OP (0.0034 ± 0.0001) than in both forests (0.0030 ± 0.0002 and 0.0028 ± 0.0001 in the PF and DF, respectively), implying additional reduction in the peat C sink function at the OP compared to the forests. Our study increases knowledge on mechanisms controlling soil CO 2 emissions across land-use change transitions in tropical peatlands, thereby enabling more accurate predictions of GHG emissions from peatland degradation.

Source: Geoderma

DOI: 10.1016/j.geoderma.2026.118030

Authors: Erin Swails, Louis-Pierre Comeau, Kristell Hergoualc’h, Jodie Hartill, Louis V. Verchot