Improved Science-Based Estimates on Emissions from Peatland Burning in Indonesia
Fig. 1: The research team conducting the studies, including researchers from
FOERDIA and UoM, during their first visit to the sites. Photo: Anna Finke

As the APFNet project “Improving capacities towards reducing greenhouse gas emissions from peat swamp forests in Indonesia”, spearheaded by the Forest Research and Development Center at the Forestry and Environment Research Development and Innovation Agency (FOERDIA) of Indonesia and the University of Melbourne (UoM) in Australia, is formally being closed in August 2022, the project can be considered a significant success. It is changing Indonesia’s Forest Reference Emissions Level (FREL) reporting already, as Mr. Buiharto, the Directorate of the GHG Inventory and MPF of the Ministry of Environment and Forestry (MoEF), stated during the completion workshop in March 2022.

The project itself aimed to improve GHG emissions estimates from burned peatlands, as these types of emissions contribute nearly 50% of the emissions from Indonesia’s land use sector, but were previously considered to be highly inaccurate. In order to improve that accuracy a new and through scientific methodology with improved parameters for estimating emissions and providing empirical data had to be developed. This undertaking was led by the scientists at FOERDIA and UoM, who subsequently published three different papers outlining their findings and the new methodology.

The first paper, titled “Identifying and addressing knowledge gaps for improving greenhouse gas emissions estimates from tropical peat forest fires by Dr. Volkova and colleagues, published in 2021, in the journal Science of the Total Environment focused on a comprehensive literature review to determine the parameters that would be required to best calculate GHG emissions from burnt peat forests based on international guidelines. In this paper, the authors found that there are still many gaps in the knowledge of carbon pools and only few recent supporting studies, supporting the need for the project to add empirical data to the knowledge base. They determined that all carbon pools, meaning aboveground carbon, carbon from deadwood, pyrogenic carbon (PyC) and peat of single and repeatedly burned forests each should be measured. They furthermore identified the minimum sampling intensity required for each forest type. Additionally, they reported first results of their measurements regarding how much carbon remains as aboveground deadwood in average after a single fire and how much remains after a second fire. They also obtained similar data for PyC, which is only rarely reported, as well as peat bulk density and peat carbon content change depending on fire frequency.
Fig. 2: Measuring out the plots at one of the sampling sites. Photo: Anna Finke
In a subsequent paper, titled “Carbon balance of tropical peat forests at different fire history and implications for carbon emissions”, by Dr. Krisnawati and colleagues, also published in the journal Science of the Total Environment in 2021, the actual total aboveground carbon (AGC) in biomass pools including trees, shrubs, deadwood, litter and char, as well as peat carbon were assessed to develop the estimates for peat swamp forest carbon stocks in response to fire and disturbance. The paper clearly showed that, in fact, not all AGC is combusted in the first or second fire, rather about half remains mainly in dead trees, woody debris and pyrogenic carbon and in the top 10cm of peat both recently burned and repeatedly burned peat forests actually store similar amounts of carbon. The study furthermore estimated the combustion factor (CF), that is the relative proportion of fuel mass consumed in fire in order to make accurate estimates of peat fire emissions for both AGC and peat carbon. It found that the CF for AGC is similar to the default value given by the Intergovernmental Panel on Climate Change (IPCC) but the CF for peat deviated quite significantly from the IPCC value, ending up being only 33-50% of its value.

Finally, in a third open-access paper and technical note titled “Loss and Recovery of Carbon in Repeatedly Burned Degraded Peatlands of Kalimantan” in the journal Fire, published by Dr. Volkova and the previous authors in 2021, the focus now narrowed down to the actual fire degradation as it happened on the study site in Central Kalimantan, Indonesia, where in the 2019 dry season 133,631 ha of degraded peatlands were burned. The authors accurately estimated how much carbon was lost from surface fuels and the top peat layer using the newly developed estimation methodology, concluding that an average of 2.5Gg of carbon were released in these fires. About 20cm of the surface was lost to combustion and a time series analysis of live green vegetation (NDVI), combined with field observations of vegetation recovery two years after the fires, indicated that it seems to take the area about 3 years to recover from this to compensate for the lost carbon.
Overall, the project thus not only contributed to the political changes mentioned above, but also contributed valuable new empirical data and an improved methodology to the scientific community, filling important knowledge gaps.