The move towards a joint global effort to conserve the world’s upland peats in recent years has seen increased attention on coastal tropical peats, particularly after repeated massive fire outbreaks that occurred since 1981, like the 1997/98 and 2015 catastrophic fires in Indonesia.
The 2015 disaster, in terms of fire activity and pollution, was the most severe one recorded since the NASA Earth Observing Satellite System began operations in the early 2000s. Its estimates show that the 2015 CO2-equivalent biomass burning emissions for all of Indonesia were between the 2013 annual fossil fuel CO2 emissions of Japan and India. Longer-term records of airport visibility in Sumatra and Kalimantan show that 2015 ranked among the worst episodes on record.
Analysis of dry season rainfall show that, due to the continued use of fire to clear and prepare land on degraded peat, the Indonesian fire environment continues to have a nonlinear sensitivity to dry conditions, and this sensitivity appears to have increased in Kalimantan. So far, of the fires occurring in coastal peat land areas, there has been very limited reports on fires in upland tropical peats.
A good example of an Asian upland peat is the Rawa Aopa, which is a large swamp in Southeast Sulawesi, Indonesia — the only major peat-swamp on the mainly mountainous island. Its vegetation and fauna are still inadequately known. With the creation of new villages as part of Indonesia's transmigration program, the human population here has increased very rapidly. Therefore, the pressure on natural resources — especially on soils and forests- is increasing. Many of its primary forests are dwindling rapidly with the expansion of cacao production. This increases threats to the Rawa Aopa, as erosion in its catchment area is leading to the rapid silting up of the swamp. The swamp holds great potential as a source of food (i.e. fish and sagoe) and income (i.e. rattan).
Fig 1: The Rawa Aopa swamp showing visible burn damage.
On Papua, peatlands are common in the montane areas above 1,000 m in New Guinea and become extensive above 3,000 m in the sub-alpine zone. In the montane mires, swamp forests and grass, or sedge fens, predominate on swampy valley bottoms. These mires may be 4–8 m in depth and up to 30,000 years in age. In Papua New Guinea (PNG) there are about 2,250 km2 of montane peatland, while Papua Province (the Indonesian western half of the island) probably contains much more. Above 3,000 m, peat soils form under blanket bog on slopes, as well as on valley floors. Vegetation types include cushion bog, grass bog and sedge fen. Typical peat depths are 0.5‒1 m on slopes, but valley floors and hollows contain up to 10 m of peat.
The estimated total extent of mountain peatland is 14,800 km2 with 5,965 km2 in PNG and about 8,800 km2 in Papua Province. The stratigraphy, age structure, and vegetation histories of 45 peatlands, or organic limned sites above 750 m, have been investigated since 1965. The montane peatlands that were formerly used for taro agriculture have declined in importance owing to the relatively recent introduction of dry land crops such as sweet potato. Old ditch systems are in some cases still in use.
Increased land pressure has led to more cropping of swamp margin and the removal of swamp forest where this is accessible. Drainage is often associated with this. Overall, the montane and subalpine peatlands of New Guinea play an important role for these peatlands in trends of hydrology of major river systems like the Mamberamo and the fly rivers.
Additionally, as is the case in Sulawesi, the Papua mountain peat are unique habitats. This underlines the need for action on mountain peats in Papua and elsewhere. Fire in tropical montane cloud forests (TMCFs) are not as rare as once believed. Andean TMCFs sit immediately below highly flammable, high-altitude grasslands (Puna/Páramo) that suffer from recurrent anthropogenic fire.
Fig 2: Hotspots 2001-2016: Papua province with confidence level >80% (Source: modis teerra aqua satellite)
On the isle of Papua, there is a continued trajectory of extractive development that is associated with high environmental cost. Part of the explanation is in the sociology of development with the expectation of a successful leader being one who delivers economic growth despite a high per capita GDP of 48 million Indonesian rupiah (seventh highest among the 34 provinces of Indonesia).
An analysis conducted by Columbia University and UN Environment on the recent trends in wildfire incidences in peat showed links to the creation of new districts, which leads to more infrastructure and the consequent use of fire. This puts pressure on peatlands. Hence, there is a need for alternative green economy development pathways. As watersheds are cross-boundary between Indonesia and Papua, the need for an evidence-based island-wide collaboration on protecting these peatlands is crucial. Up until now, the knowledge and science on these mountain peats is limited, as they are found at high altitudes. However, these upland peats are of critical importance in terms of environmental services like water supply, biodiversity and carbon sequestration.
Johan Kieft is Regional Technical Specialist with UN Environment and can be reached at email@example.com