Peatlands Must Stay Wet
Jan 30, 2020 by Eli Nur Nirmala SariBanner Image By : Indra Nugraha/Mongabay Indonesia
This article was published in mongabay.co.id on 30 January 2020.
The Indonesian government, researchers as well as non-government organizations (NGO) mostly agree that dry peatlands are one of the reasons of recurrent fires. If peatlands stay dry, wildfires will recur. Various attempts have actually been made, from raising public awareness to public enforcement, but fires continue to recur. What happened?
Peatlands are wetlands composed of organic matter from plants that are not completely decomposed. They take a long time to form. Peatland in Central Kalimantan, for example, takes 140 years to reach a depth of 0.5-1 meter.
Meanwhile, peatlands with 8-10 meters depths normally take 13,000-25,000 years to form. Letting the peatland drain would mean opening up the possibility for fire to start on the organic material, which is a masterpiece produced from ten thousand years of natural process.
Wet peat is an excellent carbon sink that can help reducing heat and mitigating the climate crisis. On the other hand, dry peat will continually release carbon into the air even without fire. If there is a fire, the amount of carbon release can significantly increase.
Another crucial issue is that fire tends to spread downward on peatlands with depths of more than 10 meters, which is common in Indonesia; and these subsurface fires are difficult to detect because the fire does not reach the surface. This type of peatland fire has generated a lot of smoke and contributed to the recurrent smog disaster over the last two decades.
This is despite President Joko Widodo’s implementation of various policies to fight fires post 2015, including rewetting the disturbed peat ecosystems to prevent fires.
Why does fire still recur?
The government has made peatland conservation and restoration efforts, including rewetting dry peatlands by blocking the peat water canals.
Peat rewetting is ideally done through full saturation, where the peatland is watered up to the near surface. The peatland surface will then become really wet until its pore spaces can no longer hold water.
This is the ideal condition to avoid carbon release into air and prevent the peatland from burning.
Unfortunately, most of the installed canal blocks have not met the full saturation requirements and still allow water to flow out at a certain depth. Such partial saturation can cause the oxygen reaction with compounds found in peat to persist. This reaction will then allow continuous release of carbon and may lead to peatlands subsidence.
But here lies the problem; full saturation is not always easy, especially when peatlands are too dry and in hydrophobicity, where they are completely unable to absorb water despite wetting. Especially in the case of hydrophobicity, peatlands wetting is prone to generating water runoff during the rainy season, exposing the peatlands to erosion.
Therefore, for more effective fire preventions, regulations that require peat to be in full-saturated condition must be enforced. Consequently, the requirement for peat water level to be maintained at 0.4 meter depth – according to Government Regulation No. 57/2016 on the Conservation and Management of Peat Ecosystem – also needs to be reviewed.
The 0.4 meter water level requirement should not equally apply to all types of peatlands. This is especially because maintaining water level at 0.4 meter does not stop the increase in carbon release and land subsidence. Another factor is that monitoring water level is also not that simple in practice.
It's time for us to establish a long-term vision related to peatland sustainability. To that end, the full saturation requirement must apply on dry peatlands. If the peatland is fully saturated with water close to its natural conditions, peat fires can be prevented and carbon release can be reduced.
It is also more feasible as satellite imageries can assist in the monitoring of saturated water conditions of the area.
If peatlands are water-saturated, all cultivation on peatlands should then be focused on paludiculture practices. Paludiculture is the cultivation of plants that can grow well on wet peatlands such as sago and purun. Paludiculture also supports the addition of organic materials into the peatland itself.
Finally, technology, research, policy and regulations must be focused on supporting the mission to establish water-saturated peatlands and paludicultural practices, with the hope that the recurrent fires in more than two decades can finally stop.
The author is a Peatland Restoration Specialist at WRI Indonesia.