The almost-forgotten Philippine peatlands and their global role
Despite the recognized importance of peatlands by the global scientific community, the Philippines is still in the early stages of identifying, measuring and understanding peatlands. Dr Rodel D. Lasco of the World Agroforestry Centre and colleagues investigated their role in storing carbon
By Tess Beyer
To conserve the carbon stored in peatland ecosystems, there is an urgent need to comprehensively catalogue the peatlands of the Philippines and protect them from land-use changes.
As part of efforts to rectify the gaps in knowledge about the nation’s peatlands, Dr Rodel D. Lasco and colleagues estimated the amount of stored carbon in the Caimpugan peatland in Agusan Marsh, Mindanao, one of the most ecologically significant wetlands in the country.
The team measured the aboveground carbon stocks of various types of peatland vegetation and litter and those stored belowground. They found that the most important carbon store was the peat soil, storing more carbon than any of the aboveground stocks combined. In total, Caimpugan peatland was estimated to store 22.9 million tonne of carbon within its 5487 hectares. This represents a substantial and space-efficient carbon store compared to other forest types in the country.
The Caimpugan peatland is under threat of clearance through conversion to agricultural land and of disturbance by eco-tourism development. Land clearance is already widespread around the periphery of the peatland in the tall-pole forests. After peat soils, these forests store the most carbon of all biomass in the area.
Dr Lasco and colleagues advise that activities around the area must be monitored in order to conserve the peatland’s ecological integrity. Peatlands can store a huge amount of carbon in the soil owing to their waterlogged and acidic nature, which slows down decomposition. Tropical peatlands accumulate peat and carbon faster than those in more temperate zones, meaning they make a substantial contribution to belowground carbon storage.
However, peatlands globally are facing many threats, most related to land-use changes linked to the increasing need for agricultural land. Neighbouring Indonesia, which contains large areas of peatland, is still learning that draining them for conversion to other land uses is not profitable considering the negative long-term consequences.
A blog by Kate Langford explains how Sumatra, Indonesia is experiencing massive land conversion for palm-oil production, threatening the livelihoods of people who live off the peatlands while dramatically increasing greenhouse-gas emissions. As part of finding ways to address these problems, one particular coffee species was grown in the peatlands within agroforestry systems. It was found to nearly equal the profitability of oil palm while causing far less environmental damage.
Given these lessons, peat soils should no longer be treated as miscellaneous or marginal lands in the Philippines. While the Philippine peatlands might have a significant impact on global greenhouse-gas mitigation, they are also important to the Philippines’ own carbon storage and other services they provide, such as unique biodiversity habitat and maintenance of watershed functions, which support not only the wellbeing of local people who rely on them for their livelihoods but also the nation and the global community.
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This work is linked to the CGIAR Research Program on Forests, Trees and Agroforestry