Borneo peat swamp forests

Ecoregion in Borneo

The Borneo peat swamp forests ecoregion, within the tropical and subtropical moist broadleaf forests biome, are on the island of Borneo, which is divided between Brunei, Indonesia and Malaysia.

Peat swamp forests occur where waterlogged soils prevent dead leaves and wood from fully decomposing, which over time creates thick layer of acidic peat. The peat swamp forests on Borneo occur in the Indonesian state of Kalimantan, the Malaysian state of Sarawak and in the Belait District of Brunei on coastal lowlands, built up behind the brackish mangrove forests and bounded by the Borneo lowland rain forests on better drained soils. There are also areas of inland river fed peat forest at higher elevations in central Kalimantan around the Mahakam Lakes and Lake Sentarum on the Kapuas River. Borneo has a tropical monsoon climate.

Over the past decade, the government of Indonesia has drained over 1 million hectares of the Borneo peat swamp forests for conversion to agricultural land under the Mega Rice Project (MRP). Between 1996 and 1998, more than 4,000 km of drainage and irrigation channels were dug, and deforestation accelerated in part through legal and illegal logging and in part through burning. The water channels, and the roads and railways built for legal forestry, opened up the region to illegal forestry. In the MRP area, forest cover dropped from 64.8% in 1991 to 45.7% in 2000, and clearance has continued since then. It appears that almost all the marketable trees have now been removed from the areas covered by the MRP. What happened was not what had been expected: the channels drained the peat forests rather than irrigating them. Where the forests had often flooded up to 2m deep in the rainy season, now their surface is dry at all times of the year. The Indonesian government has now abandoned the MRP.

Fires were used in an attempt to create agricultural lands, including large palm tree plantations to supply palm oil. The dried out peat ignites easily and also burns underground, travelling unseen beneath the surface to break out in unexpected locations. Therefore, after drainage, fires ravaged the area, destroying remaining forest and large numbers of birds, animals, reptiles and other wildlife along with new agriculture, even damaging nature reserves such as Muara Kaman and filling the air above Borneo and beyond with dense smoke and haze and releasing enormous quantities of CO2 into the atmosphere. The destruction had a major negative impact on the livelihoods of people in the area. It caused major smog related health problems amongst half a million people, who suffered from respiratory problems. The dry years of 1997 8 and 2002 3 (see El Niño) in particular saw huge fires in the drained and drying out peat swamp forests. A study for the European Space Agency found that the peat swamp forests are a significant carbon sink for the planet, and that the fires of 1997 8 may have released up to 2.5 billion tonnes, and the 2002 3 fires between 200 million to 1 billion tonnes, of carbon into the atmosphere. Using satellite images from before and after the 1997 fires, scientists calculated (Page et al, 2002) that of the that had burned 91.5% was peatland Using ground measurements of the burn depth of peat, they estimated that 0.19–0.23 gigatonnes (Gt) of carbon were released into the atmosphere through peat combustion, with a further 0.05 Gt released from burning of the overlying vegetation. Extrapolating these estimates to Indonesia as a whole, they estimated that between 0.81 and 2.57 Gt of carbon were released to the atmosphere in 1997 as a result of burning peat and vegetation in Indonesia. This is equivalent to 13–40% of the mean annual global carbon emissions from fossil fuels, and contributed greatly to the largest annual increase in atmospheric CO2 concentration detected since records began in 1957. Indonesia is currently the world's third largest carbon emitter, to a large extent due to the destruction of its ancient peat swamp forests (Pearce 2007).