Key messages
This dissertation addresses gaps of knowledge associated with how ecosystem carbon stocks and greenhouse gas emissions are affected by land use land cover change in tropical peatlands. This was the first study that paired peat swamp forests with oil palm plantations and analyzed site scale variation on greenhouse gas emissions. This study was conducted over 16 months (September 2012 to December 2013) at Tanjung Puting, Central Kalimantan province, Indonesia. Three main objectives of this study were: 1) to quantify the total ecosystem carbon stocks and potential carbon emissions from peat swamp forest conversion to oil palm plantations; 2) to measure annual soil emissions of CO2, CH4 and N2O emissions from forests and oil palm plantations; and 3) to assess the effects of fertilizer application on nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) emissions in the immature oil palm plantations.
Key messages
In a global carbon store, tropical peat swamp forests in Southeast Asia play an important role in future global climate change. Tropical peatlands store a huge amount of carbon in belowground ecosystem as peat soil. Conversion of peatswamp forest to oil palm plantation shifts the function of the natural state of forest from carbon sink to carbon source (Hergoualc’h & Verchot 2013). The rate of peatswamp forest deforestation in Indonesia has been higher (1.5-2.2% per year) than that of other forest types during 2000-2010 (Miettinen et al. 2012b), which mainly due to establishment of oil palm plantation on peat. Consequently, the conversion of primary peat swamp forests to oil palm plantations is believed to increase emissions of GHG especially CO2 emission into the atmosphere.
The Southeast Asian region has long been plagued by large-scale vegetation and peatland fires leading to local and transboundary haze pollution and extensive burned areas, which have necessitated policy responses such as the ASEAN Agreement on Transboundary Haze Pollution (AATHP) and the Second Roadmap to Haze-Free ASEAN 2023-2030 and Second ASEAN Peatland Management Strategy (APMS) 2023-2030.
Accurate and comparable measurement of burned area is essential for effective fire management and sustainable land management practices in the ASEAN region. It provides a foundation for improving tools to map wildfire risk, assessing fuel types and interpreting fire danger levels, there by enabling more informed decision-making, more effective fire prevention, suppression strategies, and enforcement of relevant regulations. Burned areas are currently being mapped in Indonesia, Malaysia and Thailand, but here is yet to be and agreed approach to ensure regular and comparable mapping across the ASEAN region.
This guideline is a comprehensive toolkit for identifying and mapping burned area, including chapters on resource needs, data requirements, mapping methodologies, validation, analysis, and reporting. This document is intended to serve as a practical toolkit for policymakers, researchers, and practitioners to develop and enhance burned area mapping and fire management in Southeast Asia. It is hoped that the guideline will contribute to the development of consistent and effective strategies for documenting and mitigating the impacts of wildfires and promoting sustainable land management practices in the region. This includes the restoration of affected land, estimation of carbon emissions, and enforcement of relevant regulations.
Heterotrophic respiration is a major component of the soil C balance however we critically lack understanding of its variation upon conversion of peat swamp forests in tropical areas. Our research focused on a primary peat swamp forest and two oil palm plantations aged 1 (OP2012) and 6 years (OP2007). Total and heterotrophic soil respiration were monitored over 13 months in paired control and trenched plots. Spatial variability was taken into account by differentiating hummocks from hollows in the forest; close to palm from far from palm positions in the plantations. Annual total soil respiration was the highest in the oldest plantation (13.8 ± 0.3 Mg C ha-1 year-1) followed by the forest and youngest plantation (12.9 ± 0.3 and 11.7 ± 0.4 Mg C ha-1 year-1, respectively). In contrast, the contribution of heterotrophic to total respiration and annual heterotrophic respiration were lower in the forest (55.1 ± 2.8%; 7.1 ± 0.4 Mg C ha-1 year-1) than in the plantations (82.5 ± 5.8 and 61.0 ± 2.3%; 9.6 ± 0.8 and 8.4 ± 0.3 Mg C ha-1 year-1 in the OP2012 and OP2007, respectively). The use of total soil respiration rates measured far from palms as an indicator of heterotrophic respiration, as proposed in the literature, overestimates peat and litter mineralization by around 21%. Preliminary budget estimates suggest that over the monitoring period, the peat was a net C source in all land uses; C loss in the plantations was more than twice the loss observed in the forest.
To accurately quantify tropical peatlands’ contribution to global greenhouse gas emissions, and to understand how emissions from peat may change in the future, long-term measurements over seasons and years are needed. Sampling soil respiration over a range of temperature and moisture conditions in the field is valuable for understanding how peat soil emissions may respond to climate change. We collected monthly measurements of total soil respiration, moisture and temperature from forest and smallholder oil palm plantations on peat in Central Kalimantan, Indonesia. Our study period, from January 2014 through September 2015, covered wet–dry transitions during 1 year with relatively normal precipitation and one El Niño year. Oil palm plots, with lower water table, had 22% higher total soil respiration (0.71 ± 0.04 g CO2 m-2 h-1) than forest plots (0.58 ± 0.04 g CO2 m-2 h-1) over the entire monitoring period. However, during the El Niño event in September 2015, despite overall lower water table levels in oil palm plots, total soil respiration was higher in forest (1.24 ± 0.20 g CO2 m-2 h-1) than in oil palm (0.90 ± 0.09 g CO2 m-2 h-1). Land-use change continues to be an important driver of carbon dioxide (CO2) emissions from Indonesian peatlands. However, the stronger response of total soil respiration to extreme drought in forest indicates the potential importance of climate regime in determining future net carbon (C) emissions from these ecosystems. Future warming and increased intensity of seasonal drying may increase C emissions from Indonesian peatlands, regardless of land-use.
The tropical peat swamp forests of South‐East Asia are being rapidly converted to agricultural plantations of oil palm and Acacia creating a significant global “hot‐spot” for CO2 emissions. However, the effect of this major perturbation has yet to be quantified in terms of global warming potential (GWP) and the Earth’s radiative budget. We used a GWP analysis and an impulse‐response model of radiative forcing to quantify the climate forcing of this shift from a long‐term carbon sink to a net source of greenhouse gases (CO2 and CH4). In the GWP analysis, five tropical peatlands were sinks in terms of their CO2 equivalent fluxes while they remained undisturbed. However, their drainage and conversion to oil palm and Acacia plantations produced a dramatic shift to very strong net CO2‐equivalent sources. The induced losses of peat carbon are ~20× greater than the natural CO2 sequestration rates. In contrast, a radiative forcing model indicates that the magnitude of this shift from a net cooling to warming effect is ultimately related to the size of an individual peatland’s carbon pool. The continuous accumulation of carbon in pristine tropical peatlands produced a progressively negative radiative forcing (i.e., cooling) that ranged from −2.1 to −6.7 nW/m2 per hectare peatland by 2010 CE, referenced to zero at the time of peat initiation. Peatland conversion to plantations leads to an immediate shift from negative to positive trend in radiative forcing (i.e., warming). If drainage persists, peak warming ranges from +3.3 to +8.7 nW/m2 per hectare of drained peatland. More importantly, this net warming impact on the Earth’s radiation budget will persist for centuries to millennia after all the peat has been oxidized to CO2. This previously unreported and undesirable impact on the Earth’s radiative balance provides a scientific rationale for conserving tropical peatlands in their pristine state.
For more than two decades, the Association of Southeast Asian Nations (ASEAN) has recognized the transboundary problem of haze. The ASEAN Agreement on Transboundary Haze Pollution (AATHP) is the foundation for intergovernmental coordination in tackling transboundary haze in the region. AATHP and its implementing modalities include the ASEAN Peatland Management Strategy (APMS) and the ASEAN Roadmap on ASEAN Cooperation towards Transboundary Haze Pollution Control with Means of Implementation (ASEAN Haze-Free Roadmap). These modalities highlight the crucial role of sustainable peatland management in reducing transboundary haze pollution and improving peatland ecosystem governance.
Peatland fires in Southeast Asia pose a serious threat to the environment, public health, and the economy. Their impacts include transboundary haze, ecosystem degradation, and massive carbon emissions that exacerbate climate change. These fires are often triggered by human activities, particularly due to its use for land clearing, and are further intensified by drought conditions caused by the El Niño phenomenon. Therefore, more effective and science-based strategies are needed to address this issue.
This manual updates the original manual by Adinugroho et al. (2005), integrating advancements in science, technology, and two decades of experience in peatland fire management and introducing various innovative approaches, including early warning systems, satellite-based hotspot monitoring, hydrological restoration, and community capacity development for fire management.
It further explains the crucial role that technology plays in fire prevention and mitigation. Systems such as SiPongi, Sipalaga, and PRIMS provide real-time data for detecting fire hotspots, monitoring peatland water levels, and coordinating fire suppression efforts, while the Fire Danger Rating System (FDRS) enables early identification of areas at high risk of fire.
The manual also highlights community involvement as a key component to successful fire management. Programs like Masyarakat Peduli Api (MPA) and incentive schemes encouraging farmers to adopt zero-burning methods have proven effective in reducing peatland fires. Lastly, the manual also presents case studies from various Southeast Asian countries, including Indonesia, Malaysia, Thailand, and Vietnam, to highlight policies and best practices in peatland fire management.
Designed for policymakers, researchers, practitioners, and the broader public, the manual aims to serves as a resource for achieving sustainable conservation and management of peatlands in Southeast Asia.