Causes and Impacts of Deforestation
Deforestation in the Brazilian Amazon may be on the rise again after reaching record-low levels last year, reports Brazil's National Space Research Institute.
Causes: Road construction in the Amazon leads to deforestation. Roads provide access to logging and mining sites while opening forest frontier land to exploitation by poor landless farmers. Brazil's Trans-Amazonian Highway was one of the most ambitious economic development programs ever devised, and one of the most spectacular failures. The project was plagued from the start. The sediments of the Amazon Basin rendered the highway unstable and subject to inundation during heavy rains, blocking traffic and leaving crops to rot. New forest had to be cleared annually. Logging was difficult due to the widespread distribution of commercially valuable trees. Rampant erosion, up to 40 tons of soil per acre (100 tons/ha) occurred after clearing.
Commercial agriculture: Recently, soybeans have become one of the most important contributors to deforestation in the Brazilian Amazon. Thanks to a new variety of soybean developed by Brazilian scientists to flourish in rainforest climate, Brazil is on the verge of supplanting the United States as the world's leading exporter of soybeans. Soybean farms cause some forest clearing directly. But they have a much greater impact on deforestation by consuming cleared land, savanna, and transitional forests, thereby pushing ranchers and slash-and-burn farmers ever deeper into the forest frontier. Soybean farming also provides a key economic and political impetus for new highways and infrastructure projects, which accelerate deforestation by other actors.
Logging: There is significant evidence that illegal logging is quite widespread in Brazil. In recent years, Ibama—Brazil's environmental enforcement agency—has made several large seizures of illegally harvested timber including one in September 2003 when 17 people were arrested for allegedly cutting 10,000 hectares worth of timber. Logging roads give colonists access to rainforest, which they exploit for fuelwood, game, building material, and temporary agricultural lands.
Hydroelectric projects have flooded vast areas of Amazon rainforest. The Balbina dam flooded some 2,400 square kilometers (920 square miles) of rainforest when it was completed. Mining has impacted some parts of the Amazon Basin. During the 1980s, over 100,000 prospectors invaded the state of Para when a large gold deposit was discovered. Miners clear forest for building material, fuel, wood collection, and subsistence agriculture.
Fires: Recent studies suggest that the Amazon rainforest may be losing its ability to stay green all year long as forest degradation and drought make it dangerously flammable. Scientists say that as much as 50 percent of the Amazon could go up in smoke should fires continue. Humidity levels were the lowest ever recorded in the Amazon in 2005.
The total area of Amazon rainforest (over 6 million km2/) is bigger than Western Europe, covering an area equivalent to two thirds of the United States of America. The forest stretches to nine countries: Bolivia, Brazil, Colombia, Ecuador, French Guyana, Guyana, Peru, Surinam and Venezuela.
The Amazon Basin is the largest reservoir of fresh water on the planet and about one fifth of all running water on the planet flows through the Amazon. The Amazon River is 6,868 km / 4000 miles long, the same distance that separates New York from Berlin. It is almost two times the length of the Mississippi (3744 km / 2340 miles) and five times longer than the river Rhine (1312km / 820 miles).
Amazon is one of the richest areas in the world in animal and plant diversity. There are more plant species in one hectare in Amazon than the whole of Europe. Over 200 species of trees can be found on one hectare of Amazon and one tree has been shown to have 72 different species of ants living in it. There are about 30 times more fish species in Amazon than in European rivers.
The Amazon Rainforest is vital for rainfall in the region as water is continually recycled through the Amazon forest by evaporation and rain. Destruction of the forest has already led to changes in the micro climate with the possibility that further destruction will accelerate micro and regional climatic change. Furthermore, the continuing logging and burning of the forest is contributing to climate change and global warming.