Spatiotemporal heterogeneity and nonlinear recovery trajectories of carbon budgets in restored pan-tropical peatlands

Pan-tropical peatlands are long-term soil carbon reservoirs and hotspots of carbon exchange, but widespread degradation has transformed many into carbon sources. Restoration is increasingly pursued to reverse these emissions and restore carbon sink function. However, the spatiotemporal heterogeneity of carbon budgets in post-restoration peatlands remains poorly quantified, limiting our ability to accurately assess mitigation potential and optimize management strategies.

Here we analyzed 23 years (2001-2023) of 0.1° gridded CO₂ and CH₄ flux data from CAMS across pan-tropical restored peatlands to characterize the complexity of post-restoration carbon dynamics. We examined spatial variability, temporal trajectories, and stage-dependent environmental drivers.

Carbon budgets in post-restoration peatlands exhibited substantial spatiotemporal heterogeneity. Overall, pan-tropical restored peatlands acted as a net carbon sink (mean = −29.7 t C ha⁻¹, 95% CI: −32.5 to −26.9), though regional patterns varied markedly. Restored Congo Basin (−29.6 t C ha⁻¹, 95% CI: −33.4 to −25.7) and Amazonian peatlands (−41.1 t C ha⁻¹, 95% CI: −45.4 to −36.7) consistently functioned as net sinks, whereas restored Southeast Asian peatlands remained net carbon sources (30.0 t C ha⁻¹, 95% CI: 20.8 to 39.2). The overall sink status reflects the larger spatial extent of Congo and Amazon sites. Temporally, carbon budgets followed non-linear trajectories, with peak sequestration occurring 10–15 years post-restoration before declining due to frequent fire events. Driver analysis revealed stage-specific management priorities: water management is critical in early stages (0-5 years) to support vegetation establishment and minimize carbon losses, while fire prevention becomes paramount in later stages (>15 years) as biomass accumulation increases flammability.

Using 23 years (2001–2023) of high-resolution (0.1°) pan-tropical data, we present a long-term assessment of post-restoration peatland carbon dynamics. Our findings reveal three critical insights for improving peatland restoration outcomes: (1) water table management is essential in early stages (0-5 years) to maximize carbon uptake; (2) peak sequestration occurs at 10-15 years, providing an optimal window for carbon crediting; and (3) fire prevention must be prioritized after 15 years to sustain gains. Incorporating this spatiotemporal complexity into carbon accounting frameworks can help refine mitigation strategies and enable stage-specific, regionally-adapted management that enhances long-term carbon sequestration.