Реферат: Deforestation Essay Research Paper Deforestation s ImpactPSC

Deforestation Essay, Research Paper

Deforestation s Impact

PSC 391

May 1, 2000

Deforestation is the permanent destruction of indigenous forests and woodlands.(WWF)

Currently, forests cover approximately one fifth of the world s land. Forests provide us with many products we use in our everyday lives. They also provide for us in other ways such from helping stop soil erosion to providing us with medical drugs, dyes and fabrics.. Humanity depends on the survival of a healthy ecosystem and deforestation is causing many social, economic and ecological problems.

Approximately 12 million hectares of forests are depleted each year. Ninety percent of the clearing occurs in the tropical rainforests. At the current rate of clearing, all tropical rainforests will be lost by the year 2050.(WWF)

There are many reasons that deforestation occurs. Commercial Logging, Ranching, and farming are the main causes of deforestation. The UNFPA (United Nations Fund for Population Activities) said in it s 1990 report that population growth may have been responsible for as much as eighty percent of the forest land cleared between 1971 and 1986 to make room for agriculture, cattle ranching, houses, roads and industries (Ramphal, 1992, p.55)

Commercial Logging is accounting for the elimination of about 20,000 square feet of tropical forests per year. The increasing demand for fuel wood as populations expand is another important factor leading to deforestation. In most developing areas, wood is the primary source of fuel. In many of these areas, the demand for fuel wood is rising at about the rate of population growth, and ahead of the destruction committed by loggers. (Hardaway, 1994, p. 201). One third of the world s people depend on wood for fuel as a significant energy source (Dudley).

Tropical forests cover about 10 per cent of the world s dry land surface, mostly located in South America and Asia (Dudley 6). In the tropical forests of the world, deforestation is occurring for agriculture and livestock pastures.

In the agricultural sector, the importance of export crops is a driving force behind deforestation. ). It is estimated that in that period nearly sixty million hectares of forest were converted to farmland and a similar amount of forest was put to non-agricultural uses. This is equivalent to the mass of twelve hundred square meters of forest added to the population (Ramphal, 1992, p. 57). Quite often, areas of forest were cleared in such a way (ex.: slash and burn) that they will never grow back. After a forest area has been converted to grazing lands or intensive farming, the soil will only sustain it for a few years. Then the land is left lifeless.

Cattle ranching is another of the many reasons why trees are cut down recklessly in tropical areas. Over the last two decades, beef production in Brazil has risen sharply from 2.85 million metric tons in 1980 to 4.96 metric tons in 1996(FOA 1998). This rise in production corresponds with dramatic increases in deforestation levels in Brazil.

What do forests do for us? Forests are a precious link in the life systems of our planet. They are a part of these vital ecosystem services without which earth would not have been habitable by the human species in the first place and would certainly have become inhabitable again. Forests have crucial roles in the carbon, nitrogen, and oxygen cycles that nourish and sustain life on earth. They protect the watersheds that support farming and influence climate and rainfall (Lindahl-Kiessling, 1994, p.167). They save the soil from erosion and are home to thousands of species, and forest peoples whose lives depend on them. They are also a source for industrial and medical purposes.

What are the effects of deforestation Forests are great natural repositories of carbon. Trees breathe in carbon dioxide and store it, acting as carbon reservoirs. As such, they are invaluable agents in keeping the level of carbon in the atmosphere stable. As forests are destroyed worldwide, especially by burning, carbon dioxide is released into the air, adding to the stock of greenhouse gases that are now warming our planet and changing its climate. Carbon dioxide accounts for half of global warming, and fossil fuels account for two-thirds of manmade carbon dioxide (Ehrlich and Ehrlich, 1970, p.134). The consumption of energy from fossil fuels; coal, oil, and natural gas used for industrial, commercial, residential, transportation and other purpose results in large emissions. Thus, the energy sector accounts for nearly half of global warming, forty six percent.

Forestland is also the world s main storehouse of species, the plants, animals, birds, and insects with which earth has been blessed. Tropical forests expand roughly between ten degrees North and south of the equator. In a small portion of the earth lies nearly half of earth s biological species, many endemic. The rapid rate of deforestation is erasing our bio-diversity. One major factor that the forests carry is that they are the home to over one half of the world s total species (Dudley). Currently we are discovering 20 new species of insects and 15 species of plants each day (Dudley 13).

Also the medical treatments, cures and vaccines will never be discovered if there are no forests to discover them in.

Desertification is closely related with deforestation. When a forest is cut of burned down, the trees, which once held the rich topsoil together and protected it s under the canopy are gone. The soil becomes susceptible to high sunlight and heavy rainfall this quickly damages the topsoil in tropical rainforest, causing them to loose soil nutrients and also dries out the soil.

Our forests are invaluable resource to all. Not just for the wood, but as they maintain life on earth. They are continuing to be destroyed at a rate that will not permit their return when humanity realizes its errors. Our forests are perhaps the most threatened aspect of earth as a result of population growth, and the one that we can least afford to lose.

Using the International Futures Software, I attempted to slow the effects of deforestation by manipulating factor which I could control by making changes and interpolating them into the working file and comparing them to the base file. I first examined the world s forest without making any changes to the file(figure 1) Each of the areas had a fairly consent land use without many fluxuations with the exception of Africa which declined steadily. Next I decide to see how Forests would react as the Worlds population grew. Figure 2 illistrates the the land use for Africa and Latin America after a change in the population from 263.119 to 5000.

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