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The thick haze caused by Forest Fires, covering major parts of Indonesia and Malaysia during the dry season, are presently a hot item in discussions concerning environmental impacts. The haze has a strong polluting effect, has a bad smell and causes severe distress for persons with respiration problems. It is claimed that the fires also have a world wide greenhouse effect.
Photo: (below). Thick haze caused by Fires in Bush Land and Marshes on Dolak Island, Papua (Frederik Hendrik Island) in December 1982.
What causes the Fires?
Land Clearing Activities. The latest haze problems caused by fires were recorded in January/February 2000 in Riau and Jambi provinces, Sumatra. These fires were related to land clearing activities for new oilpalm and pulp wood plantations in these two provinces. These new oilpalm and pulp wood plantations are mainly found in the low uplands on the east coast which are easily accessible, but recently they are more and more also found in the Tidal Lowlands. Although a very important cause of the present fire/haze problems, these land clearing activities are not the only cause of the forest fires.
Over-logged forests. Forestry Concessions are based on the Selective Cutting system. This means only a few trees are cut per hectare and the Concession Holder has to wait xx years before he can cut again a few suitable trees. In principle this system is sustainable in many areas.(Not in peat soil areas, see below). However it appears that Selectice Cutting Forestry Concession areas are a source of man-ignited fires. Mainly in places which are over-logged and where much more trees have been cut than will be sustainable for the Selective Cutting system.(always illegally). The cut wood remnants left in the forest easily burn and are often set afire by passing humans for un-clear reasons. These wild fires are especially hazardous in Peat Soil areas. Peat soil may burn over large areas in the upper 30 cm topsoil and the fire is extremely difficult to put out. These burning peat soils surely will contribute also to the greenhouse effect.
There is a new major hazard of the peat fires in the over-logged areas. Concession holders will get permission to clear-cut the forest after the peat fire, because the forest looks "dead" and the wood must be saved. Next to the total clear-cut, the Concession Holders will receive permission to change the area into pulp-wood or oil palm plantations. That looks financially attractive but many of these plantations are not sustainable because by subsidence of the peat they become not drainable and consequently totally useless in the future.
An important cause of the present problems is that it has been never realised in the past that Forestry Concessions on Peat Soils under Natural Conditions are not sustainable anyhow. Degraded Peat Swamp Forests, burnt or non-burnt *), will never restore to the old glory of virgin peat swamp forests without special human interference. See Webpage Problems, swamp forests on peat soils how they may have a chance to be restored. See also Webpage Thesis, Negative Hydrological effects in Peat soils.
*)When the peat forests are not clear-cut after the forest fires the question remains what happens with the vegetation under re-growth. The latest Landsat images of 2001 indicate a complete living vegetation in the previously burnt peat forest areas. However this vegetation will be not more than low bush and ferns, as re-growth of a ombrogenous peat forest is impossible.
Wild fires in Bush and Marsh Land. During the extreme long dry season in 1982 I found out that in Papua (Irian Jaya) local people set major parts of Bush and Marsh land afire. At that time already some transmigration land clearing activities took place near Merauke and Timika. This might have contributed to the haze problem, but the whole south coast from Fak-Fak to Merauke over more than 1000 km length up to the footslopes of the high mountains was covered for months by a thick haze caused by fires. In Papua mainly bush land and marshes were burning and set afire by locals, often with the explanation that the new plant growth after the fires attracts more wild animals and birds for hunting. In the nineteen sixties, seventies and eighties, during an extreme dry season, Melaleuca Bush land was also set afire over large areas in the Lampung/South Sumatra provinces in the Tidal Lowlands. The purpose was to grow for one season a rice crop by direct sowing. In my experience only bush and marsh land burns. Un-disturbed Primary Swamp Forest rarely burns and certainly not over large areas. All these wild fires in Bush and Marsh land will cause a severe haze, but will not contribute to the greenhouse effect by an increased release of CO2 to the atmosphere. (When the same density of vegetation returns after the fires and no "fossil" peat has been burned)
In my opinion the fires in over-logged forests on ombrogenous peat soils should have the highest priority when planning protection measures; followed by a better control on the land clearing activities and licenses given for concessions on peat soils. These forest fires on peat soils are most difficult to control, may have a greenhouse effect and have the potential to burn over very large areas.
The NOAA satellite using the thermic band, which is able to look through the haze and locate the fire sources, can very well monitor fires. In this way the European funded FFPCP locates the forest fires in Sumatra. These hotspots should have an Overlay in GIS with soil survey maps in the Coastal regions, which locate the peat soils. A hotspot in a forested peat soil area will most likely detect a location in an over-logged area. (remember: Primary Swamp Forest, even properly logged forest by selective cuttings will most likely not burn!). That will make the GIS Overlay process a powerful tool for the Indonesian Government to monitor the forestry activities in peat areas. Hotspots in peat areas will also locate land clearing activities for plantations which might be not sustainable. (See also above)
The Nation Wide Study for Coastal Swamp lands in Sumatra, Kalimantan and Irian Jaya, Euroconsult 1984, has surveyed and mapped most of the Tidal Lowlands of Indonesia, including the peat soil areas. This Study is probably to date the most accurate source for locating peat soils throughout Indonesia as it is based on two years of field surveys throughout Indonesia with a large team of surveyors. Presently there are numerous more detailed surveys available, but none of these surveys and maps will have a Nation Wide coverage, based on field work, including hydrology, topography and soil investigations.
Some Landsat images with peat soil areas suffering from forest fires are on Webpage Landsat
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