for National Geographic News
Researchers have confirmed a long-suspected link between logging and the
devastation of forest fires in tropical rain forests.
Forest fires that ripped through East Kalimantan, Indonesia, in 1998 burned more than 12 million acres (5 million hectares).
The Center for International Forestry Research (CIFOR), based in Bogor, Indonesia, estimated that the economic loss to Indonesia exceeded U.S. $9 billion and that carbon emissions were high enough to make the country one of the largest polluters in the world.
Using remote sensing, satellite imagery, and ground and aerial surveys, a team of German and Indonesian researchers found that the bulk of the roughly 12 million acres (5 million hectares) consumed by fire occurred in timber concessions, plantations, and on land converted to agricultural use and then left fallow.
Fire damage was by far the worst in areas that had been recently logged. Almost two-thirds of the pulp wood plantations in East Kalimantan were destroyed by the fires.
Less than one million acres (400,000 hectares) were in protected, and presumably pristine, forests.
Forests Under Siege
Tropical rain forests don't usually burn. In their natural state, fuel loads are low and not highly flammable, and the humidity is high even during drought years.
But Indonesia's rain forests have experienced the effects of heavy logging and slash-and-burn agriculture, resulting in weakened ecosystems. Indonesia's forests burned following droughts in 1982-83, 1987, 1991, and 1994.
The drought that followed the 1997-98 El Niño was particularly harsh, said Florian Siegert, a professor at Ludwig Maximilians University in Munich, Germany. The extent of fire damage that occurred in early spring of 1998 was unprecedented, he said.
Siegert is the lead author on the study, which was published in the November 22 issue of the journal Nature.
The study confirms earlier suspicions that logging waste and dense undergrowth of fast-growing pioneer species provide large amounts of fuel that feeds the rampant spread of forest fires.
Pressure on Indonesia's rain forests has been building for 30 years. Government relocation programs encouraged people to move from densely populated regions to less populated islands such as Borneo, where East Kalimantan is located. The increased population pressure has led to uncontrolled conversion of forest to agricultural use, which is done through slash-and-burn techniques.
SOURCES AND RELATED WEB SITES