When the Portuguese landed in Brazil 500 years ago the sight that greeted them was of a huge rain forest, which then ran along much of Brazil's Atlantic coast. In more recent times, there has been an outcry over the destruction of the much larger Amazon forest. But its devastation is nothing compared to Brazil's Atlantic forest. About 86% of Brazil's Amazon forest is still intact but only about 7% of the Atlantic forest remains. In this paper, I will explain why the Atlantic forest was destroyed, why deforestation happens, and the effects of rain forest destruction and the effect it is having on the Earth.
Much of the Atlantic forest was destroyed to make way for farmers to plant sugar, coffee, and other crops, and later for growing cities like Sao Paulo and Rio de Janeiro. Between 1990 and 1995, 1.2 million acres were destroyed (Reid, 2000).
Clearance for living space, commercial logging, for farming, roads and railways, forest fires, and mining and drilling are all connected with deforestation.
People have been living in and around tropical rain forests for tens of thousands of years, taking what they needed from the wealth of natural resources available without compromising their environment. However, in the last 200 years populations have expanded, requiring more and more space for housing and farming. For example, Costa Rica has a population of over 3 million people, heavily concentrated in the Central Valley. Well over one-half of the national population lives in this area, which represents only 5% of the country's land area, and almost one-half of the population is considered to live in urban areas.
The population growth rate is relatively high and if it continues at the present rate, the population will double in only 28 years (Hecht, 1989). Commercial logging can occur selectively, where only the economically valuable species are cut or by clear cutting, where all the trees are cut. Commercial logging uses heavy machinery, such as bulldozers, road graders, and log skidders, to remove cut trees and build roads.
Another cause of deforestation is known as shifting cultivating. Indigenous people have farmed the rain forest, cutting down trees to allow cultivation of crops and grazing space for animals, and moving on when the soil becomes less fertile. This is no threat to the forests; provided that used areas are left to regenerate for long periods before repeating the process. Problems arise when the land is not allowed time to recover, and intensive farming results in irreversible soil degradation. This is what is happening now due to the needs of growing population. Some sources identify shifting cultivation as the cause of 70 % of the deforestation in Africa.
As with shifting cultivation, if logging is carried out in a controlled way it can be implemented with only minor disturbances to the environment. It is when the cutting of trees exceeds tree production that logging becomes a problem. Before mechanical logging took over from the use of handsaws, axes, and animal power, it could be argued that the timber trade posed little threat to tropical rain forests, but with the arrival of chainsaws, tractors, roads and railways had a much greater impact. Previously inaccessible areas have now become prime targets for commercial logging companies, and poor management has led to major losses.
Other factors such as cutting trees for charcoal, and clearance for mining and the extraction of oil are considered less damaging than shifting cultivation and commercial logging, but still pose a threat the rain forests.
Once cleared of trees, the rain forest topsoil, which can take thousands of years to accumulate, can be eroded in a relatively short amount of time. This makes the land unstable, and can lead to disastrous flooding since there is no soil to soak up the rain. Forest clearance also leaves humans without food and shelter, and leads to the disappearance of ways of life, which have been unchanged for thousands of years. However, the most damaging effect of forest clearance is its impact on the climate of the planet. We have all heard of global warming and the greenhouse effect, which is caused by carbon dioxide build up in the atmosphere. Trees and other green plants absorb carbon dioxide and produce oxygen through photosynthesis. The destruction of tropical rain forests would cause the carbon dioxide levels to become very high in the atmosphere. Not to mention that many the trees cut down are burned or left to rot, releasing even more carbon dioxide (Revkin, 1990).
Another effect of deforestation would be the inability to discover new plants and animals. It is estimated that only a small fraction of plants and animals living in the rain forests have been identified, and some scientists think that many of these may hold the keys to finding cures for some of the most deadly diseases known to man. For example, the US National Cancer Institute has catalogued over 3,000 plants with anti-cancer properties.
The obvious solution to the problem is to stop cutting trees. But is that the only answer? Global trade in tropical timber is a multi-billion dollar industry and calls for the stopping of cutting would certainly be met with resistance. But perhaps there is no need to halt timber production completely. Logging management could emphasis guidelines on how deforestation takes place. Areas of the rain forest that are too sensitive can be designated as protected areas. Education could also be a useful tool, with education they could inform those people who pose a threat to the forests. Only this way will we be able to stop, and eventually reverse, the degradation of the tropical rain forests.