Resilience of a peatland in Central Sumatra, Indonesia to past anthropogenic disturbance: Improving conservation and restoration designs using palaeoecology

1. Tropical peatlands, which provide important functions such as biodiversity provisioning and carbon (C) storage, are currently threatened by land-use conversions. Thus, conservation and restoration efforts are needed to maintain their functions. Conservation concepts aiming to separate human from ecosystems are no longer conceivable. Therefore, understanding peatland resilience to human disturbance, that is the ability of peatland ecosystems to maintain their structure and function despite perturbations and to return to their predisturbance states, can assist with integrating human needs into conservation strategies and improving restoration effectiveness. 2. Understanding ecosystem resilience is often impeded by a lack of long-term data, which can be obtained from palaeoecological studies. Located close to the archaeological remains of the Malayu Empire, the Sungai Buluh peatland in Sumatra, Indonesia provides an opportunity to study the resilience of a tropical peatland to past human disturbance. We subjected a 250-cm-long peat core to palynological, charcoal and C content analyses to delineate the anthropogenic impact on the peatland and the ecosystem's response. 3. The results revealed that extensive human activities in Sungai Buluh such as logging, grazing/cut-and-carry, and wild-harvesting started soon after humans occupied the vicinity of the peatland c. 1,000 cal yr BP. Even without fire use and cultivation, these activities were able to alter vegetation composition and decrease the peatland's C sequestration capacity. 4. Following site abandonment after the demise of the Malayu Empire at c. 600 cal yr BP, the palaeoecological record suggests that the Sungai Buluh peatland recovered in terms of both floristic composition and C sink function, with the latter recovering faster (c. 60 years) than the former (c. 170 years). 5. Synthesis. The palaeoecological record from Sungai Buluh provides the first evidence of tropical peatland recovery following human disturbance, which can help improve present peatland conservation/restoration strategies. The design of peatland wise-use strategies can mimic the "resilience-friendly" human activities identified in this study. Consideration should also be given to selecting rapidly regenerating taxa for cost-and-effort-efficient restoration strategies. Additionally, the 170-year recovery time of the Sungai Buluh peatland suggests that the 60 year timeframe currently allocated in most tropical peatland restoration