Rain Forest Destruction

Introduction

Rain forest destruction refers to the loss of tropical and temperate rain forests due to logging and burning, and due to the toxic by-products of activities such as mining. In temperate regions on the West Coast of the United States and Canada, the destruction of rain forest is due to logging of centuries-old trees for their lumber. The same is true in tropical rain forests, but in addition, the trees are removed to clear land for conversion to agriculture and raising of livestock.

Sizable portions of the rain forests in Borneo, the Amazon watershed, Vancouver Island in British Columbia, Sri Lanka, Malaysia, and Central America, as some examples, have already been destroyed.

The Brazilian rain forest, which makes up approximately about 30% of total rain forest area of the globe, is being destroyed at a rate of over 5 million acres each year. Continuing this pace will completely decimate this rain forest by 2050. Similarly, if action is not taken to curb the rate of destruction, estimates are that by that time over 80% of the world’s remaining rain forests will have been lost.

Clear-cutting for agricultural purposes is only a short-term benefit, since the removal of the forest stops the cycling of nutrients into the soil. In the Amazon, for example, once fertile soils fail to support crop growth within several years, without the addition of fertilizers.

Historical Background and Scientific Foundations

Rain forest destruction benefits only the landowner, perhaps only for a short time. Removal of trees near watercourses eliminates a zone that can restrict the movement of pollutants and sediment from washing into the stream or river. In the absence of the trees, the watercourse can become polluted. As well, run off of agriculture fertilizer can increase the levels of nitrogen and phosphorus in the water, which can stimulate the explosive increase in the numbers of microorganisms such as algae. The growth of the microbes can deplete the oxygen content of the water, which makes the water uninhabitable for fish and vegetation. In addition, fires can occur more easily since regions of the forest are open, increasing the movement of air.

In a tropical rain forest, the loss of the forest canopy makes the ground sunnier and drier, and more prone to erosion of nutrients in the soil during rainfall. Within several years, the formerly rich soil becomes claylike and infertile. This limits the productive lifetime of a cattle farm or cropland that has been created by the rain forest destruction.

Loss of temperate forests also increases soil erosion, but for a different reason. The temperate soil is no longer as stabilized by tree roots, and heavy precipitation will increasingly remove the soil.

In the Amazon, an initiative that was intended to decrease the pace of rain forest destruction led to road construction to selected sited designated for clear-cut-ting. Although in theory this allows greater control over forest logging, the reality has been very different. Since stringent monitoring of such a large land area as the Amazon watershed is virtually impossible, roads have provided access to the rain forest for illegal logging activities. In a study published in 2005 in the journal Science, researchers reported on the analysis of the pace of rain forest destruction in Brazil. Satellite photos demonstrated that the selective logging campaign has doubled the pace of rain forest destruction.

Impacts and Issues

Even though the rain forest destruction yields only a short-term benefit, much of the destruction is accomplished by sustenance farmers who survive on the income they can derive by clearing fields for crops.

Strategies to effectively stop rain forest destruction will have to address the need for a substitute local economic benefit. Ironically, in tropical regions, economic prosperity could be more attainable by using the natural bounty of the rain forest. Calculations have indicated that rain forest land cleared for agriculture yields about $60 per acre, while land used for the raising of cattle nets an owner about $600 per acre for the few years that the land is productive. However, the renewable and sustainable resource of the rain forest, including fruits and nuts, can yield up to $2,400 per acre.

The solution is not as simple as re-planting, since it takes a long time for the nutrients present in the plants to be transferred to the soil in amounts that make the soil fertile. Fertilization, which is intended to supplement a balanced and productive soil, not to supply everything needed for growth, is also not a solution

A vital nutrient needed for forests and cropland is water. Typically, this comes in the form of rain. In tropical regions, the massive loss of trees due to rain forest

WORDS TO KNOW

EROSION: The wearing away of the soil or rock over time.

GLOBAL WARMING: Warming of Earth’s atmosphere that results from an increase in the concentration of gases that store heat, such as carbon dioxide (C02).

SILVICULTURE: Management of the development, composition, and long-term health of a forest ecosystem. The objective is often to allow logging of the forest over many years.

SUSTAINABLE RESOURCE: A resource that can be renewed or maintained indefinitely.

destruction reduces the water vapor released from leaves into the atmosphere. This reduces cloud formation. In tropical regions, rain forest destruction may create deserts in what are now among the wettest regions on Earth.

Rain forest destruction affects biological diversity; rain forests harbor 60-70% of all biological species even though they occupy about 2% of Earth’s surface. Much of the life in rain forests remains undiscovered.

The warming of the atmosphere has been accelerating since the mid-twentieth century. As acknowledged in the 2007 report by the Intergovernmental Panel on Climate Change (IPCC), this warming is most likely due to human activities such as the accelerated release of carbon dioxide and other so-called greenhouse gases. Rain forests are a natural carbon sink, or region that retains carbon. Their loss is increasing the release of carbon dioxide, thereby driving more global warming.

See Also Agricultural Practice Impacts; Cultural Practices and Environmental Destruction; Human Impacts; Landslides; Reforestation; Runoff

BIBLIOGRAPHY

Books

Diamond, Jared. Collapse: How Societies Choose to Fail or Succeed. New York: Viking, 2004.

Starr, Christopher. Woodland Management. Ramsbury, UK: Crowood Press, 2005.

Wild, Anthony. Coffee: A Dark History. New York: Norton, 2005.

Periodicals

Asner, Gregory, et al. “Selective Logging in the Brazilian Amazon.” Science 310 (2005): 480-482.

Web Sites

Save the Rainforest.http://www.savetherainforest.org/index.htm (accessed April 7, 2008).