As soil is washed down into rivers it causes problems for fish and people. Fish suffer because water becomes clouded and spawning grounds fill with silt, while people have trouble navigating waterways that are shallower because of the increased amount of dirt in the water. Meanwhile, farmers lose topsoil that is needed for growing crops, and dams generate less electricity as water is lost to runoff.
On steep hillsides, loss of forest can trigger landslides. For example, thousands of people were killed in Central America during Hurricane Mitch of 1998 when deforested hillsides collapsed. Had forests been maintained, the death toll would have been lower.
Forests also play an important role in reducing damage from flooding by reducing the rate of water runoff.
During the devastating 2004 Indian Ocean tsunami, areas where mangrove forests had been cut down suffered more devastation than areas where healthy mangrove forests remained as a buffer. Mangroves also help protect against coastal erosion.
By Rhett Butler
Date published: June 24, 2004 | Last updated: December 5, 2015