Humans owe a debt of thanks to forests. Forests clear the air, moderate the climate, protect soil from erosion and keep water clean. Forests provide lumber, fuel and food, as well as raw material for paper, plastics, medicines and a thousand other products. Forests offer refuge to the landless, the rebellious and the weary.
How have humans repaid forests? By chopping, sawing, slashing, burning, blasting and bulldozing them. By poisoning them with herbicides, mine tailings and acid rain; scarring them with logging roads, skid trails and sawmills; drowning them behind dams; clearing them for farms and pastures, and paving them over for highways and cities.
In the last 5,000 years, humans have reduced forests from roughly 50% of the Earth's land surface to 20%. This ages-old devastation is accelerating. According to United Nations estimates, Africa has lost 23% of its forests since 1950, Central America 38% and the Himalayan watershed 40%. Tropical rain forests are going fast. Acid rain has damaged half of West Germany's trees, killing many. U.S. forests continue to shrink in area and now contain only a fifth as much timber as they did when the Pilgrims landed.
Deforestation has exacted an enormous toll through the ages in environmental damage, economic deterioration and human misery. Soil erosion, flooding and silting of rivers, reservoirs, canals and harbors are among the environmental effects. Deforestation has created barren hillsides, creeping sand dunes, desert-like heaths, water-logged moors, malarial swamps.
Decline and Fall of Empires
Deforestation has had a major impact on society. Historians contend deforestation of Greece and Italy contributed significantly to the decline and fall of the ancient Greek and Roman empires. Ascendancy gradually passed from the deforested Mediterranean region to heavily forested Northern Europe. Much later, a deforested England lost control of its timber-rich American colonies.
Wars have been fought for possession of forests, and many a forest has deliberately been destroyed to punish an enemy. Conquerors and colonizers have taken forested foreign lands after deforesting and ruining their own. Cities have been abandoned and capitals relocated because of deforestation.
Deforestation has even influenced religion. Some scholars trace the Jewish and Moslem prohibitions against eating pork to deforestation of the Near East, which deprived pigs of their natural forest habitat and made them too expensive to feed and keep cool.
The deforestation currently taking place in the tropical Third World strikes experts as all the more tragic because it repeats mistakes the temperate First World already has made. Says Stanley E. Krugman, director of timber management research for the U.S. Forest Service, "A lot of countries aren't learning from our mistakes, just as we failed to learn from the Europeans."
Failure to learn from past mistakes and to correct the current situation has economic, political and social ramifications that extend beyond the areas undergoing deforestation. Far from being a narrow issue of concern only to residents of deforested areas, nature lovers and lumber merchants, deforestation in an increasingly interdependent world economy directly affects U.S. interests in terms of trade, investment and political stability.
To be fair, people aren't responsible for all deforestation. Windstorms, volcanic eruptions, lightning fires, drought and other natural disasters also take their toll. So do deer, porcupines, beavers, gophers, rats and other wild animals that feed on trees and sometimes kill them. Dwarf mistletoe and other parasitic plants suck and smother trees to death. And beetles, budworms, gypsy moths and other insects, along with rusts, rots, blights and other diseases, consume more trees than humans harvest.
Making Matters Worse
Still, humans have a history of making matters worse by altering the balance of nature and inadvertently causing deforestation. In the Pacific, the introduction of non-native deer, goats and pigs onto islands where they had no natural enemies swelled their populations and sent them rampaging through the forests like locusts. In Arizona, a government policy of making the Kaibab Plateau into a game preserve for deer by eliminating the coyotes, wolves and bobcats that had preyed on them increased their numbers beyond anything the region could support. As a result, the forest thinned and the deer starved.
Even more havoc followed the importation of the gypsy moth from France in 1869. Introduced into Massachusetts as part of a misguided silkworm-breeding experiment, the pest soon escaped from the laboratory to nearby woods. Since then it has spread across the country, leaving caterpillar-defoliated woods in its wake.