Indonesia has launched a plan to established some 6.2 million ha of industrial forest plantation (Hutan Tanaman Industri [HTI]) by the year 2000. The main purposes are to cover the lack of raw materials and to avoid the decline and degradation of tropical rain forest. The programme is not proceeding well because of a number of disturbing activities. One of these problems is forest fire. In 1994, for example, the total area affected by fire was about 5.1 million ha. This number includes wildfires on newly established forest plantations, shifting cultivation areas, grass land fires and the use of fire for land clearing (agricultural purposes).
During that period (August-October 1994) wildfires occurred in a reforestation area, the Subanjeriji forest block, located in one forest concession area in South Sumatra, Indonesia, where 46,617 ha of Acacia mangium was planted. A total of 7,372 ha (= 17%) was destroyed (Tab.1) in only three months. Arson might be the reason behind those fires for the following reasons: (1) administratively, the status of the land is not clear ,i.e. whether it belongs to the company or the people; (2) relationships between the company and the contractor are not cordial; (3) relationship between the workers and the contractor are also poor, and (4) the company staff themselves are managing the plantation.
Tab.1. Area planted and burnt(August-October 1994) in the Subanjeriji forest block
Research shows that fire destroyed all plantations of 1, 2, 3 and 4-year old A. mangium. No trees were recovered and no natural regeneration was recognized on the forest floor. Surprisingly, in all the stages (except 1-year) Magnesium, Potassium, Sodium, total-Nitrogen (except 2-year), organic carbon, and pH (except 3-years) decreased significantly one year after burning. One of the reasons why so much of the plantation was burned was the high levels of poorly maintained fuel available, even in very young plantations. The daily increase of burnt areas at those times should have not happened if the information about the results of the research on fire had been available. Unfortunately a lack of research makes this information very scarce, and inhibits activities against such fires.
Ongoing and Future Fire Research
Previous research has shown how fire behaves in the plantation as a result of different fuel load, fuel bed depth, flame height, rate of the spread of fire, and so on. Most importantly, the behavior of fire in the plantation is now clearly understood, and the reasons why so much plantation has burned have also been found. In addition, the reasons as to why there is no natural regeneration on the forest floor and a reduction of pH and several exchangeable-cations have also been found. Many questions however have emerged following previous research:
How should the fuel load be managed in order to prevent fire invading the plantation?
How much of the minerals, seeds in the forest floor and insects are lost following burning?
What should be done in the burnt area ? Is there any change in the soil quality?
Why are these litters, shrubs, and trees burnt?
How should the problem of seeds becoming weeds on the forest floor in the second rotation be solved?
How should plantations be protected from fire invasion?
To answer those questions, the following research is being conducted:
Seed and litter production (since 1995)
Tree spacing in relation to canopy cover
Heat effect on seed germination
The possible utilization of prescribed burning
Flammability of the plant community (litters, shrubs, trees)
Utilization of decomposers to reduce fuel load
Seed storage on and under the forest floor
Design of fuel breaks in the plantation
The results of this research will hopefully provide valuable information concerning activities against fire and rehabilitation of burnt areas.
From: Bambang Hero Saharjo
Laboratory of Forest Protection,
Division of Forest Management
Faculty of Forestry,
Bogor Agricultural University,
Bogor 16001, West Java,
INDONESIA Present working
Laboratory of Tropical Forest Resources
Division of Forest and Biomaterials Science,
Graduate School of Agriculture,