Guidelines (IPCC 2003, 2006, 2014, 2019). IPCC provides two general approaches
to estimate annual change in biomass and the resulted emission, i.e. the “Gain–Loss”
Method based on the estimated annual change in biomass from the biomass gain and
biomass loss, and the “Stock-Difference” Method which estimates the difference in
the total carbon stock of the biomass at times t 2 and t 1 . Several countries, including
Indonesia, have initiated to develop specific or local emission factors in their regions
for various purposes including for reporting Forest Reference Emission Level
(FREL), National GHG Inventory, and Nationally Determined Contributions
(NDC) (MOEF 2016, 2017, 2019). In the FREL report submitted to UNFCCC
(which was later used in the GHG inventory and NDC reports from forestry sector
including peatland), Indonesia has used country specific emission factors from
aboveground biomass for both primary and secondary peat swamp forests,
i.e. 174.6–210.8 t ha
À1 (95% CI) and 151.4–167.3 t ha
À1 (95% CI), respectively,
generated from National Forest Inventory data (MOEF 2016).
The 2006 IPCC Guidelines also provide guidance on how GHGs emission
released from peat due to disturbance, such as drained peat (Chap. 4, Volume 4)
and extracted peat (Chap. 7, Volume 4). This guideline is then supplemented through
the 2013 IPCC Wetlands Supplement document by updating emission from
“Drained Inland Organic Soils” due to peat extraction, forest management, croplands/grasslands activities, and adding the “rewetted organic soils” component
through rewetting, canal blocking, and paludiculture activities (IPCC 2014).
Rewetting organic soil will increase the water level so it will reduce CO 2 emission,
reduce N 2 O emission to almost zero, but increase CH 4 emission compared to when it
is drained because the oxygen content decreases as the methanogenesis process
occurs (Beetz et al. 2013).
15.3.1 Drained Peatlands
For peat experiencing drainage, the approach used to estimate GHGs emission is
based on the impact of the drainage depth level (water level) on CO 2 , CH 4 , and N 2 O
gases, in addition to emission resulting from peat burning.
15.3.1.1 Carbon Dioxide (CO 2 ) Emission
CO 2 emission from drained peat consists of “on-site CO 2 -C emission/removal by
drained organic soils” and “emission from dissolved organic carbon exported from
drained organic soils.” According to IPCC Guideline Wetlands Supplement (IPCC
2014), the default values of emission factors that can be used to calculate “on-site
CO 2 -C emission/removal by drained organic soils” on tropical peatlands are: 5.3 t
CO 2 –C ha
À1 year
À1 (for forestland, shrubland), 20 t CO 2 –C ha
À1 year
À1 (for
plantations, short-rotation), 15 t CO 2 –C ha
À1 year
À1 (for plantations, long-rotation),
14 t CO 2 –C ha
À1 year
À1 (for cropland and fallow), 11 t CO 2 –C ha
À1 year
À1 (for
15 Climate-Responsible Management of Tropical Peatlands: The Need for Integrated. . .
449
to estimate annual change in biomass and the resulted emission, i.e. the “Gain–Loss”
Method based on the estimated annual change in biomass from the biomass gain and
biomass loss, and the “Stock-Difference” Method which estimates the difference in
the total carbon stock of the biomass at times t 2 and t 1 . Several countries, including
Indonesia, have initiated to develop specific or local emission factors in their regions
for various purposes including for reporting Forest Reference Emission Level
(FREL), National GHG Inventory, and Nationally Determined Contributions
(NDC) (MOEF 2016, 2017, 2019). In the FREL report submitted to UNFCCC
(which was later used in the GHG inventory and NDC reports from forestry sector
including peatland), Indonesia has used country specific emission factors from
aboveground biomass for both primary and secondary peat swamp forests,
i.e. 174.6–210.8 t ha
À1 (95% CI) and 151.4–167.3 t ha
À1 (95% CI), respectively,
generated from National Forest Inventory data (MOEF 2016).
The 2006 IPCC Guidelines also provide guidance on how GHGs emission
released from peat due to disturbance, such as drained peat (Chap. 4, Volume 4)
and extracted peat (Chap. 7, Volume 4). This guideline is then supplemented through
the 2013 IPCC Wetlands Supplement document by updating emission from
“Drained Inland Organic Soils” due to peat extraction, forest management, croplands/grasslands activities, and adding the “rewetted organic soils” component
through rewetting, canal blocking, and paludiculture activities (IPCC 2014).
Rewetting organic soil will increase the water level so it will reduce CO 2 emission,
reduce N 2 O emission to almost zero, but increase CH 4 emission compared to when it
is drained because the oxygen content decreases as the methanogenesis process
occurs (Beetz et al. 2013).
15.3.1 Drained Peatlands
For peat experiencing drainage, the approach used to estimate GHGs emission is
based on the impact of the drainage depth level (water level) on CO 2 , CH 4 , and N 2 O
gases, in addition to emission resulting from peat burning.
15.3.1.1 Carbon Dioxide (CO 2 ) Emission
CO 2 emission from drained peat consists of “on-site CO 2 -C emission/removal by
drained organic soils” and “emission from dissolved organic carbon exported from
drained organic soils.” According to IPCC Guideline Wetlands Supplement (IPCC
2014), the default values of emission factors that can be used to calculate “on-site
CO 2 -C emission/removal by drained organic soils” on tropical peatlands are: 5.3 t
CO 2 –C ha
À1 year
À1 (for forestland, shrubland), 20 t CO 2 –C ha
À1 year
À1 (for
plantations, short-rotation), 15 t CO 2 –C ha
À1 year
À1 (for plantations, long-rotation),
14 t CO 2 –C ha
À1 year
À1 (for cropland and fallow), 11 t CO 2 –C ha
À1 year
À1 (for
15 Climate-Responsible Management of Tropical Peatlands: The Need for Integrated. . .
449