The study examines the net greenhouse gas balance of fiber wood plantations on peat in Indonesia, particularly focusing on the emissions from various land-use types. It finds that conversion of intact peatland to acacia plantations increases greenhouse gas emissions, while conserving intact peatlands can significantly reduce emissions. The findings highlight the importance of tropical peatland conservation as a climate solution, impacting regional carbon budgets.

1. Net Greenhouse Gas Balance of Fibre Wood Plantation on Peat in Indonesia
Chandra Deshmukh, Ari Susanto, Nardi, Nurholis, Sofyan Kurnianto, Yogi Suardiwerianto, M. Hendrizal Ade
Rhinaldy Reyzaldi Mahfiz, Ankur Desai, Susan Page, Alexander Cobb, Takashi Hirano, Frédéric Guérin, Dominique
Serça, Yves Prairie, Fahmuddin Agus, Dwi Astiani, Supiandi Sabiham& Chris Evans
Deshmukh, C.S., Susanto, A.P., Nardi, N. et al. Net greenhouse gas balance of fibre wood plantation on peat in Indonesia.
Nature 616, 740–746 (2023). https://doi.org/10.1038/s41586-023-05860-9

2. Tropical peatlands play an important role in regional and global GHG budget
• Tropical peatlands hold >125 t/ha of Irrecoverable Carbon (if lost, this carbon could not be recovered by mid-
21st century, by when we need to reach net-zero emissions to avoid the worst climate impacts)
Source: Noon, M.L., Goldstein, A., Ledezma, J.C. et al. Mapping the irrecoverable carbon in Earth’s ecosystems. Nat Sustain 5, 37–46 (2022). 2

3. Converted peatland (Managed + Degraded) (Mha) Emissions (GtCO2e yr-1)
Northern 27 0.42 (0.26–0.57)
Tropics 25 1.48 (0.04–2.79)
Large variability of GHG emissions were observed from tropical peatlands
Sources: Leifeld, J.et. al. The underappreciated potential of peatlands in global climate change mitigation strategies. Nat Commun. (2018)
Burba, G. Illustrative Maps of Past and Present Eddy Covariance Measurement Locations: II. High-Resolution Images. (2019) 3
• Measurements of contemporary carbon exchange from tropical peatlands remains limited;
• North America: 731 sites
• Europe: 720 sites
• SEA: ~20 sites
APRIL’s
registered
sites

4. 1. Determine the magnitudes of greenhouse gas exchanges
over various land-uses in tropical peatlands while
incorporating all existing sources and sinks;
2. Understand the link between GHG exchanges and
associated changes in the environmental variables.
Research Questions and Aims of The Study
• How much GHG will be emitted from 1 hectare of Acacia plantation establishment?
• How much GHG emissions can be avoided if 1 hectare of remaining intact peat swamp forest is protected from
degradation?
4

5. • Measures net balance of all vertical emission and
removal pathways;
• Provides high frequency measurements
every 30 min => temporal variability;
• Provides measurements at an ecosystem-scale
>200 ha => spatial variability.
Methane Vertical wind
speed
CO2/H2O
Eddy Covariance to measure ecosystem level of GHG exchange
Eddy Covariance Flux Tower
5
40 m

6. Indonesia
GHG exchanges measurements across three land uses on peat in Riau, Indonesia
Study site Land cover type Measurement period
Site#1 Intact peatland Jun 2017 – May 2022
Site#2 Degraded peatland (the mosaic of scrubland, degraded and secondary forests) Oct 2016 – May 2022
Site#3 Peatland plantation (Acacia crassicarpa plantation) Oct 2016 – May 2021
Three land-uses on peatland of Kampar Peninsula (an ombrogenous, ~700.000 ha area, formed ~5.100 yr ago)
Sumatra
6

7. Dynamics of carbon dioxide fluxes along one-full Acacia plantation rotation
• Over the plantation rotation, net CO2 ecosystem exchange (9.5 tCO2 ha−1 yr−1) + carbon export in harvested
wood (20.5 tCO2 ha−1 yr−1) indicates that the Acacia plantation functioned as a CO2 source of 30.0 tCO2
ha−1 yr−1;
• IPCC default values (73 tCO2 ha−1 yr−1) and Hooijer et al. (2012) (80-90 tCO2 ha−1 yr−1) were higher than
those from our study.
7
Source: Deshmukh, C. S., et al. Net greenhouse gas balance of fibre wood plantation on peat in Indonesia. Nature (2023)
Drösler, M. et al. in 2013 Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories: Wetlands (eds Hiraishi, T. et al.) 2.1–2.79 (IPCC, 2013)
Hooijer, A. et al. Subsidence and carbon loss in drained tropical peatlands. Biogeosciences 9, 1053–1071 (2012)

8. • Conversion of intact site to Acacia plantation results in a long-term net increase in greenhouse gas emissions of
18.1 tCO2-eq ha−1 yr−1
• Establishment of Acacia plantation from degraded site results in a lower long-term GHG emissions of −7.5 tCO2-
eq ha−1 yr−1
• Use of tree biomass for bioenergy in place of coal burning results in avoided emissions of -7.3 tCO2-eq ha-1 yr-1
• Avoided emission from conserving the remaining intact peatland = -25.7 tCO2-eq ha-1 yr-1
Net GHG balance over various land-uses in tropical peatlands
Source: Deshmukh, C. S., et al. Net greenhouse gas balance of fiber wood plantation on peat in Indonesia. Nature. (2023) 8

9. -0.8 -0.6 -0.4 -0.2 0.0 0.2
-25
0
25
50
75
100
R2
= 0.83; P< 0.05
CO2 flux = -64.65GWL-10.33
Hooijer et al.
Jauhiainen et al.
Eddy covariance
Subsidence and chamber (tropics)
UK and Irish (Evans et al.)
This study (tropics)
Other study (tropics)
Groundwater lev el (m)
Net
carbon
dioxide
fluxes
(tCO
2
ha
-1
yr
-1
)
-0.8 -0.6 -0.4 -0.2 0.0 0.2
0.0
0.1
0.2
0.3
0.4
R2
= 0.69; P > 0.05
CH4 flux = 0.188e(2.5GWL)
Groundw ater lev el (m)
Net
methane
fluxes
(tCH
4
ha
-1
yr
-1
)
a b
Groundwater level controls carbon dioxide (CO2) Fluxes
• Carbon dioxide flux measurements at different groundwater levels from eddy covariance studies are
substantially lower than those derived from previous soil-chamber and subsidence studies
• Importance: Useful to predict CO2 fluxes with some degree of confidence for regional & national GHG
inventory;
Source: Deshmukh, C. S., et al. Net greenhouse gas balance of fibre wood plantation on peat in Indonesia. Nature (2023)
Tiemeyer, B., et al., A new methodology for organic soils in national greenhouse gas inventories: Data synthesis, derivation and application, Ecol. Indic (2020). 9
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2
-10
0
10
20
30
40
50
Groundw ater lev el (m)
CO
2
fluxes
(tCO
2
ha
-1
yr
-1
)
Tiemeyer et al. 2020
Evans et al. 2021

10. Want to learn more? Check out Deshmukh et al. (2023) Nature https://doi.org/10.1038/s41586-023-05860-9
• GHG emissions from Acacia plantation were higher than those from intact site, but lower than the IPCC
emission factor for plantations
• Tropical peatland conservation: powerful and cost effective nature-based climate solution + supports unique
biodiversity.
Takeaway Messages
10

11. Improving Understanding of GHG Emission Factors from Various Pathways
Stem GHG Emission in Intact forest and
Acacia plantation
Fluvial Carbon Export Ebullition
Diffusion in River (intact) and
Canal (plantation)
River Canal 11

12. Thank you!
Dedicated Team
12

13. • Decreased rainfall, increased seasonality and frequent days without rainfall are resulting in groundwater level
drawdowns, which cause carbon loss.
Intact Peat Swamp Forest Losing Carbon in Current Rainfall Regimes
Source : Deshmukh, C. S., et al. Net greenhouse gas balance of fibre wood plantation on peat in Indonesia. Nature (2023)
Liu, Laibao., et al., Increasingly negative tropical water–interannual CO2 growth rate coupling, Nature (2023)
Garcin, Yannick., et al. Hydroclimatic vulnerability of peat carbon in the central Congo Basin. Nature (2022) 13
Peatland in the central Congo Basin
also shows hydroclimatic vulnerability
and released previously stored carbon
due to prolonged dry period (ghost
interval) (Garcin et al., 2022);
• Decrease in water availability driven by
El Niño reduces the forest’s capacity to
absorb carbon. (Liu et al., 2023).