The removal of trees for commercial timber products (logging) is causing the removal of about 20,000 square miles of tropical forests each year. Areas of intense logging include Para, Brazil where lumber mills (used for timber processing) are common place, explaining the states relatively high deforestation rates (see table 2 for figures). The rate of deforestation by logging is however highest in Malaysia where 90 percent of its forested lands have been licensed for logging. The tropical woods once processed are transported mainly to the developed nations, where they can be used to create valuable items, like furniture. The import of tropical woods to developed nations has increased 15 fold since 1950, particular in Japan, which accounts for over one-third of the international market. While gathering fuel wood destroys around 5,000 square miles and severely disturbs another 5,000 square miles of tropical rainforest each year. As fuel wood is the only affordable and abundant supply of fuel available to the rainforest settlers. Haiti for instance has only about 1.5% of its original forest cover, due to logging, burning and conversion to farmland. The main threat to the remaining fragments is cutting trees to produce charcoal, a major cooking fuel.
Cattle ranching is a main cause of tropical deforestation especially in Costa Rica where many foreign companies have bought large tracts of forest in order to raise cattle for beef export, mainly to the United States. As the financial cost of raising beef in Costa Rica is only about half the cost in the U.S, thus reducing the production cost of hamburgers for example. Explaining why multi-national fast food chains, like Macdonald’s operate with in these tropical regions. In order for cattle ranching to take place grassland must be established where the original tropical vegetation has been felled. The grassland remains productive for around 8 years where after it is taken over by scrub-growth as the cattle remove much of the grassland vegetation. The total amount of tropical forests being lost each year due to these four types of human activity comes to around 30-37,000 square miles with 70-77,000 square miles being severely disrupted. This corresponds to an area the size of Massachusetts being affected each month.
An indirect cause of tropical deforestation is third-world debt, as nearly all of the countries containing tropical rainforests owe many billions of US dollars to either the World Bank or to the International Monetary Fund. They in turn are forcing third world countries, mainly in Latin America, to destroy their rainforests in order to reduce their debt. The World Bank has suggested that Brazil should only preserve and manage only 50 000 square kilometres, or 1.4 percent, of its rainforest. This in essence is totally unreasonable as third world debt can never be paid off even it the rainforests where completely destroyed. Brazil spends over 40 percent of the money it earns on exports on the yearly interest on its foreign debt, which totals over $100 billion. At the expense of rainforest management programmes and human quality of life.
Deforestation can be most noted in some of the world’s largest rainforests and in areas where there has been a significant reduction in the rainforests original size. This would include the Amazon rainforest (Brazil, Bolivia, Peru, Ecuador) where nearly 50 percent (over 1 million square Km) of the rainforest has been felled over the last 40 years. While countries like the Cote D’Ivoire have lost 97.5 percent of its original tropical forest cover (see table ‘1’ for actual figures). Most of the consequences of tropical deforestation lie on the fact that many cleared lands are not (when utilised) suited for long-term farming or ranching, as they quickly degrade once the forest has been cut and burnt. Unlike the fertile soils of temperate latitudes, most tropical forest soils cannot sustain annual cropping. The carrying capacity of the soil will not support intensive annual cropping or cattle grazing without rapid, irreversible degradation as it exposes the soil to the intensity of the tropical sun and torrential rains, which can cause the formation of gullies. Dislocation of iron oxides with in the soil by rainwater causes a hard ‘iron pan’ to form on the lands surface, making it impermeable to further root growth from vegetation. The intense rainfall, through leaching, also removes nutrients from the soil, reducing its fertility. Land degradation in dry forest zones (Africa, Australia) causes desertification. Desertification is the consequence of extremes in climatic variation and unsustainable land use methods. Growing populations are making ever-increasing demands on the land to produce more, leading to intensification beyond the carrying capacity of the land.
The damming of tropical rivers such as the Amazon has increased lateral and basal river erosion downstream as sediment often gets trapped behind the dam, causing it to silt. The dams also create fluctuations in the rivers flow, causing wide spread flooding during times of heavy rainfall. This along with water pollution from mining gives a loss of safe, potable water, thus putting communities health at risk from diseases. One of the most controversial consequences of deforestation has been the reduction in the forests biodiversity. For example the removal of a thousand hectares of forest could mean the extinction of hundreds of undiscovered plant and animal species. Some of which could be used to fight serious modern-day diseases like cancer or Aids. The exact number of species lost each year is not know due to our limited knowledge of tropical ecosystems and inadequate monitoring systems, but we do know that human-induced deforestation is causing mass-extinctions of individual species. The social consequences of deforestation can be quite extreme and long-term. Many of the indigenous peoples of the Brazilian states of Amazonas and Rondônia have been encroached upon by slash-and-burn farmers, ranchers, and gold miners, often resulting in violent confrontations. The intrusion of outsiders destroys traditional life styles, customs, and religious beliefs.
Deforestation is an important contributor to global warming, despite its contribution relative to other factors being known. The principal cause of global warming is the excessive discharges in industrialized countries of greenhouse gases, mostly from the burning of fossil fuels. Annual discharges from burning fossil fuels are estimated to be about 6,000 million tons of carbon, mostly in the form of carbon dioxide. It is thought that an additional 2,000 million tons or about 25 percent of the total carbon dioxide emissions are a consequence of deforestation and forest fires. At the regional level, deforestation disrupts normal weather patterns, creating hotter and drier weather. This could increase the potential for desertification and crop failures in the worlds remaining rainforests. A warmer climate would also increase the number of forest fires, thus releasing more carbon dioxide. Global warming would cause the displacement of the planets major vegetation regimes, however the most serious consequence would be the melting of the ice caps. This in turn would cause coastal flooding of some of the world major cities, like London with a loss of rich agricultural lands.
Traditional efforts of controlling tropical deforestation concentrate on weakly enforced laws and regulations with stronger factions being able to avoid them. In third world countries the focus has been on aid-funded programmes, notably the international Tropical Forests Action Programme. These however have proven insufficient to reduce the rates of deforestation since they fail to tackle the under-lying causes. Today market-based, voluntary approaches are appearing, like forest certification and timber labeling, so favouring the products of sustainable forest management. Forest management is also commonplace with in the Amazon rainforest reservations, due to the restriction on logging and other activities. Their main aim is to preserve areas of rare endangered species whilst protecting the Amazonian Indians settlement area. Deforestation in its entirety is the result of many direct actions stimulated by various root causes, meaning if we were to take action it would require us to focus on the many fronts or issues it poses, not just one or two. Long-term effort is required to encourage sustainable forest management, in order to achieve this the environmental, social, and economic aspects of management must be balanced despite the septic-ness of many national policies. As deforestation can produce both benefits and costs, it is important to estimate the gains and losses for each possible act of deforestation. The UN has recommended that every nation should preserve at least 12 percent of its represented ecosystem, though this is unlike to be enforced. Deforestation is seen overall as a social or economic safety regulator by political minds in the third world, as they tend to think that giving people forestland will ease any politically sensitive problems, such as rural development. In economic terms, the tropical forests destroyed each year represent a loss in forest capital valued at US $45 billion (Hansen, 1997). By destroying the forests, all potential future revenues and future employment that could be derived from their sustainable management for timber and non-timber products would disappear.
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