Wood Extraction

Wood has always been an important fuel for forest dwellers, and even in the mid-20th century 80% of all wood harvested was for fuel (see Chap. 1). Commercial loggers in the tropics concentrated only on a few valuable timber species such as teak and mahogany. Following World War II, woods of lighter density were also extracted to be sold in national or foreign markets. From 19501980, tropical hardwood exports rose 14-fold, from 4.6 to 61.2 million m3 of roundwood per year (FAO 1989; see also Chaps. 1 and 6).

In the 1990s, there was a dramatic increase in logging in the tropics. In many developing nations, tariffs and trade barriers fell, while new international free-trade agreements promoted foreign investment, particularly in natural resource-based industries such as timber (Laurance 2000). Each year, approximately 6 million ha of tropical forest was logged (Whitmore 1997). Although only between 2 and 40 trees may be harvested per hectare, 10-40% of the remaining forest biomass is killed or severely damaged during logging operations (Uhl et al. 1991; Verissimo et al. 1992). The main damage results from the labyrinth of roads, bulldozer trails, and small clearings in the forest. The heavy machinery kills many smaller trees, damages and compacts the soil, and increases soil erosion and stream sedimentation (see also Chap. 5). A study in Indonesia found that even though only 3% of the trees were cut, the logging operation damaged 49% of the trees in the forest (Urquhart et al. 1998). Once opened, the forest is increasingly vulnerable to hunters, ranchers, and shifting cultivators (Wilkie 1992). Logging also increases the vulnerability of forests to fire by rupturing the forest canopy and creating piles of dry, flammable debris. In the Amazon and Borneo, millions of hectares of logged forest were destroyed by wildfires during the 1982-1983 and 1997-1998 El Nino droughts (Brown 1998; Laurance 1998).

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