Where logging is mechanized, bulldozers are used to construct roads into the forest. Frequently, wide swaths are cut into the forest on either side of the road to keep it dry. Little effort is made to reinforce the road or provide culverts to deflect rainwater. Often these roads are made on slopes. Under these circumstances, water pools in depressions, killing plants and trees, the soil erodes in the heavy rainfall, and the silty water runs into streams, lakes and estuaries. These roads provide access to areas where trees have been felled by loggers with chain saws. Many of these trees are never found by the extractors who follow the loggers into the forest – a major source of waste. The downed trees are dragged by a vehicle (or, sometimes, elephants) to cleared areas, or “landings,” which causes considerable damage to the remaining forest. A study conducted in Para State in Brazil demonstrated that mechanized logging removed 2.9 – 9.3 trees per hectare, of 83 different species. In the logging procedure, the canopy cover was reduced 35%; for each 6.4 trees removed, 250 trees of a diameter greater than 10 cm were damaged severely (uprooted – almost half; stems broken – about 40%; loss of bark – about 10%) (Uhl, 1994). According to another study, in the state of Pahang, Malaysia, to recover 3.3% of the trees by “selective” logging, nearly 51% of total trees were destroyed, most of them by bulldozers sent to retrieve the felled trees (Johns, 1991). For non-selective logging the figures are much worse – often 65-80% of the trees will be destroyed during extraction of commercial species. Little thought is given by the logging companies to regeneration, sustainability, or the reduction of fire hazards.