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The delicate science behind managing peatlands

Posted: Jul 24, 2020 4 minute read Dr Götz Martin 0 Likes

Peatlands are a unique ecosystem formed through the accumulation of partially decayed vegetation or organic matter in waterlogged and acidic conditions over thousands of years. They store tremendous amounts of carbon in their soil and are important for the environment, but can be complex to upkeep. When peatlands are not managed well, they will degrade through the exposure to oxygen which results in peat subsidence and, the stored carbon is emitted as greenhouse gases (GHG). If peatland is drained, it becomes especially prone to fire.

Understanding and enhancing the amount of carbon stored in peatlands is critical in its management. In fact, it is a key performance indicator in GAR’s peat rehabilitation project in PT Agro Lestari Mandiri in Ketapang, West Kalimantan.

Rehabilitation on its way to keep the peat wet and to minimise GHG emissions
Rehabilitation on its way to keep the peat wet and to minimise GHG emissions in the long term.

Together with our project partner, we have designed a monitoring system to measure and report carbon gains or losses. We prevent carbon losses in peatlands through:

  1. Maintaining a high water level. This results in reduced (in an ideal case no) decomposition through oxidation and fire
  2. Avoiding new land clearing through engagement with local communities and the provision of alternative livelihood options
  3. Rehabilitation of forest cover

But because peatlands are constantly exposed to air when degraded, it is difficult to maintain net neutral simply by preventing carbon losses. We also need to boost carbon gains by:

  1. Increasing absorption through revegetation

Through these four steps, the goal is to achieve carbon positive peatlands.

Measuring and monitoring
Constant attention and monitoring is needed to achieve our goal.

Piezometers are used to measure the water levels within the peatland weekly. Water level is not only an indicator on how fire prone the peat is at a given time, it can also be used as a very rough proxy to estimate how much peat is exposed to oxygen and is decomposing and releasing carbon and other greenhouse gases (measured in carbon dioxide equivalent (CO2e)).

When the water level falls below a certain level, we flag it to the plantation team to raise their fire detection and response readiness. Measures include the manning of watch towers, permanent patrols (jointly with community members) and closure of water gates to adjust the water levels inside the peat areas.

Subsidence poles are another tool we use to measure and verify the depth by which the peat body has been shrinking (subsiding) over time. We do this monthly to estimate carbon loss through decomposition.

If the peatland is in good condition, no oxidation/subsidence occurs beyond the seasonal shrinkage and swelling. If you don’t manage the peat properly, there will be a net reduction in height, which means CO2e has been released from the decomposing peatland.

Finally, we have permanent sampling plots to measure the annual increment of biomass above ground. This includes the trees we have been replanting in the peatlands but also the natural revegetation. The data from these sampling plots provide the annual absorption of CO2e from the atmosphere.

Remaining islands of non-burned forest
Remaining islands of non-burned forest are used as nucleus for natural revegetation.

Peat fires and their impact

As the annual dry season in Indonesia approaches, we are increasing alert levels in our peat areas to avoid fires. Fires in 2019 affected 2,000 hectares of peat in PT Agro Lestari Mandiri, and we have conducted site visits to collect primary data to calculate the carbon loss.

Analysis of the site findings indicates factual support for the hope that the 2019 fires resulted in less combustion of biomass, and therefore less CO2e emissions than initially anticipated. Results show that burn scars have an average depth of 3cm below ground, which is less than previously projected. This is likely due to our re-wetting and fire control activities. Without these initiatives, the land area affected by the fires might also have been larger.

To avoid a repeat of last year, we have been strengthening these measures:

  • Better water management: We are providing clearer work instructions so that once piezometers reach certain water levels, operations personnel will start pumping water from nearby rivers into the peat to keep it moist.
  • Re-vegetation: We continue to re-plant trees in the area because if revegetation efforts are successful, the carbon gain from the biomass increase would outpace the carbon loss from the fires last year.
  • Stronger community engagement: More communication and education with neighbouring communities about the dangers of slash and burn agriculture, so that they will stop setting the peatlands on fire. Although with the COVID-19 pandemic this year, we’ve had to limit outreach only to communities where we currently have people embedded.
Chilli and vegetable cultivation in Tajok Kayong village
Chilli and vegetable cultivation in Tajok Kayong village – a result of our community engagement programmes near PT Agro Lestari Mandiri.

A year-round responsibility
In these dry months of July to September, fires and haze become a hot topic in the media. You begin to see articles discussing how governments and companies are preparing. What you don’t see is that the work of fire prevention is all year-round and doesn’t just happen right before the dry season. From the close attention we pay to our peatlands, our multi-faceted Desa Makmur Peduli Api (Fire Free) Programme, to creating new educational materials for school children, GAR’s initiatives show our commitment to eliminate the threat of fires in and around our concessions.

Sometimes no matter how prepared you are, there will be elements that don’t go in your favour (errant villagers, water shortages). This was unfortunately the case for Indonesia’s and our peatlands in 2019. Right now, we’re keeping a watchful eye on how COVID-19 might affect the dry season this year. With our continued investment in technology, and teams monitoring hotspots and water levels, we are hopeful for a more positive outcome in 2020.

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