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VANISHING WORLD RAINFORESTS FORESTS FOR LIFE: The growing problem of deforestation and its disastrous effects. Today, after just a single generation of wanton destruction, Haiti stands stripped of
its trees. Forty years ago, in 1950, forests still covered 80% of
the country; now, the figure down to less than 10%. Nor is Haiti
alone. Many tropical countries, which were heavily forested only a
few decades ago, are now virtually denuded of trees. Africa has lost
almost half of its tropical forests, while the Americas have lost a
third of theirs. In Madagascar, off the East Coast of Africa, 93% of
the island's original primary forest has been destroyed in the last
40 years. TREES: The Earth's Inheritors Forests are the natural vegetation of a vast area of the world. In all such places, provided that nature is allowed to take its course and that the damage is not too extensive, a newly cleared patch of ground will be colonized first by small pioneer plants, then by larger plants, including grasses. Bushes will take over and shade out the grasses, and among them will be tree saplings. These will eventually grow tall enough to crowd out the bushes and form a dense stand of slender trees, which obscure most of the light. In time, and this may take hundreds of years, some of these trees will lose out to others, creating a mature forest where large, ancient trees are interspersed with much younger ones, and in which there are occasional glades where an old tree has fallen, allowing sunlight to reach the forest floor. VITAL ROLE Forests play a vital role. They protect the soils and regulate water supplies. In those tropical regions that experience torrential rain, adequate forest cover is vital for human welfare. Clearing the forest dramatically increases surface run-off from rainfall, because far more rain reaches the ground rather than being caught in the canopy. The soil itself is also unable to absorb as much water after clearance, largely as a result of compaction. Forested soils are now known to absorb 10 times more water than pasture-water which, once the forest has gone, simply cascades over the denuded soil straight into the local streams and rivers. The destruction of forests can produce drought as well as flooding, especially in monsoon regions, with their seasonal rainfall. Forest soils hold water well, releasing it slowly into local streams and rivers. They thus smooth out the extremes of climate, spreading the supply of water evenly throughout the year. Without the buffering action of the forests there is often a drought-flood cycle with massive floods during the monsoon periods, alternating with devastating droughts during the dry season. Over the millennia, forests (the trees and plants) have developed an impressive array of chemical defenses to pests. Many of these chemical compounds act as drugs, of have some other useful application. The rainforest species now being condemned to extinction may thus be of enormous potential benefit to humans in medicine, agriculture and other industries. THE PEOPLES OF THE FOREST As a direct result of deforestation, thousands of millions of people in the Third World are being condemned to living a degraded and impoverished existence, with very little prospect of ever improving their lot. But, for the 50 million tribal people who live in the forest itself the impact of deforestation is far works. It extends beyond the ecological devastation caused by the loss of their forests to the loss of their culture, their identity, and their whole way of life. They rely on the forest for their food, the building materials for their houses, the wood for their agricultural implements, the herbs for their traditional medicines, the fibers and dyes for their clothes, and the materials for their religious and cultural artifacts. Just as important, they have deep-rooted cultural ties with the forest itself-ties which extend beyond the economic and which give meaning to their lives and cohesion to their cultures. Not surprisingly, for most tribal peoples the destruction of their forest world spells physical and social doom-many succumb to disease while others drift into the slums, where they fall prey to alcoholism, prostitution, drugs, and mental illness. FORESTS AND CLIMATE Remote as the destruction of forests and their peoples might seem to the inhabitants of cities they too, may be gravely affected by the wider climatic effects of deforestation. Forests contain massive amounts of carbon and deforestation, especially when the forest is burned as happens on such a large scale in Latin America, adds considerable quantities of carbon dioxide to the atmosphere. Deforestation is thus adding appreciably to the greenhouse effect with devastating consequences for both North and South. Deforestation may also disrupt another vitally important climatic mechanism. The rainfall is returned promptly to the atmosphere, both through evaporation and through transpiration that process whereby plants take up water from the soil and pump it out through the stomata of the leaves. The vapor, like perspiration, serves to cool the plants down so that they can continue to photosynthesize; it also provides up to 50% of the rain that precipitates downwind. The clouds formed by the vapor pumped into the atmosphere by tropical forests reflect back sunlight into outer space, thus cooling the tropics. Some of the vapor is transported to higher latitudes where it helps heat up the atmosphere. The Amazon rainforest, as a consequence of its size, is therefore an integral part of a giant solar heat pump that keeps the tropics cool while transporting heat to colder climes. Some climatologists now suggest that widespread deforestation over the Amazon Basin may disrupt the transfer of heat from the tropics to the Northern Hemisphere, which, in turn, could become cooler. SAVING THE FORESTS International trade, and the consumer society that feeds it, ensures that we are all parties to the destruction of the forests. In that respect, saving the forests relies as much on the international community adopting policies that reduce the ecological impact of their activities as on any measures that can be taken in the rainforest countries themselves. Given the enormity of the changes required changes that will affect everything we do it would be understandable if the determination to save the forests gave way to despair. But, despite the gloom, there is light at the end of the tunnel. Our future security does not lie in planting trees for pulping every few years, but rather in regenerating the genuine wealth of forests. Trees are not merely a source of foreign exchange and profit, but protectors of the soil, providers of fodder for their animals, and sources of nuts, fruit and other products. What do the forests bear? Soil, water and pure air. With the need to plant more trees now more pressing than ever if we are to combat our problems globally, it is a message that all will do well to learn. WHY THE DOWN SLIDE? Fires, grazing, and over intensive clearance. || The Timber Trade: Worldwide the tropical timber industry is held responsible for degrading some 5 million hectares of primary rainforest annually. Much of the wood is used to make cheap, throwaway goods. REPERCUSSIONS The impact on wildlife is severe. The direct physical impact of logging is considerable and cannot compare to that in natural clearings. Erosion is a particular problem, leading to landslides, to the silting up of rivers, and to the destruction of fish spawning grounds. By simplifying the forests, modern forestry practices have also increased the problem of insect pests. In undisturbed forest, insect populations are kept under control both by the predators that feed on them and, by the mix of tree species as most pests feed on one type of tree. One problem is that many pest species have developed resistance to the pesticides used: another is that the pesticides have frequently proved as effective, if not more effective, against the predators of the pests. The enormous increase in the use of motor cars and aircraft, the emission of thousands of man-made chemicals, the massive increase in power generation, and the industrialization of agriculture have all added dramatically to the number of pollutants in the environment. Among those which have caused most damage to trees are sulfur dioxide, nitrogen oxides, and volatile hydrocarbons, which react with water and sunlight to form sulfuric and nitric acids, ammonium salts, and other mineral acids. These then fall to earth, often thousands of miles from where they were emitted, as dry particles or as acidified rain, snow, or fog. FOREST FIRES Some time back Southeast Asia was in the news for some of the worst forest fires of the decade. We saw pictures of vast pristine virgin forest ablaze. Forest fires emit many pollutants and gases into the air. Carbon monoxide and carbon dioxide are two of these gases. These gases can cause serious atmospheric problems in large quantities. Carbon dioxide, along with methane and water vapor, make up the greenhouse gases. These three gases are responsible for the greenhouse effect. They absorb and redirect heat back down to earth. Normally this heat would escape into space. Because this heat is trapped in the atmosphere, scientists believe that it could be making the earth warmer. Global warming could have devastating effects. It could cause the ice caps to melt, weather patterns to shift, and disrupt ecosystems. But although forest fires cause severe harm, they can also have some benefits. If you want a healthy forest, then you want forest fires, within reason. Fires should not always be viewed as destroyers of forests, but instead as one of nature's primary gardening tools. They help to control damaging insect populations; they reduce the spread of diseases that would otherwise denude large areas of trees; they recycle nutrients back into the soil so that they can produce vibrant new growth; and most importantly, frequent fires reduce the build up of fuel in the forest that leads inevitably to one of those huge, intensely hot, and dangerous forest fires that consume everything in it's path including large healthy trees. But if fires caused by humans from campfires, logging, trash burning, etc. were added to the naturally occurring ones, then you would end up with too many fires. Excerpts taken by Bob
Buckter, |