Monday, February 23, 2009

AMAZONE

Amazon FactsThe Amazon river basin contains the largest rainforest on Earth and covers approximately 40% of the South American continent. The Amazon Rainforest is located within eight countries, Brazil contains 60% of the forest, with Colombia, Peru, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guyana containing the rest.The Amazon forest is a natural reservoir of genetic diversity, containing the largest and most species rich tract of tropical rainforest that exists. The Amazon contains an amazing thirty-percent of Earth's species. One square kilometre of Amazon can contain about 90,000 tons of living plants! It's also amazing to consider that one in five of all the birds in the world make the rainforest their home.The Amazon basin is drained by the Amazon river, the worlds second longest after the Nile and the river is essentially the lifeline of the forest. The river is the most voluminous on Earth.A few hundred years ago tropical rainforests covered as much as 12% of the Earth's land surface, but today the figure is less than 5%. The largest stretch of rainforest can be found in the Amazon river basin, over half of which lies in Brazil.Why is the Amazon so important in the context of global warming?The rainforest acts as a major store of Carbon and produces enormous amounts of oxygen. The Amazon has been referred to as "The lungs of the Earth" because of its affect on the climate. The way this is achieved is of course through photosynthesis, the process by which green plants/trees use the energy from sunlight to produce food by taking carbon dioxide (Co2) from the air and water and converting them to carbon. The by-product of this is oxygen.The Amazon therefore helps recycle carbon dioxide by turning it into oxygen, and its estimated that the Amazon produces about 20% of this essential gas for Earth's atmosphere.Trees, plants and Co2Levels of co2 in the atmosphere have been measured since 1958 from a monitoring station located on Mauna Loa volcano in Hawaii and they show sharp annual increases and decreases in co2 levels, similar to the tooth on a saw. The readings almost mimic a breath of air being taken in and out; it's almost as if the Earth is breathing. The readings correspond to the amount of vegetation on the planet (most of which is contained in the Northern Hemisphere, as the landmass there is greater), taking in co2, and giving out oxygen. During the Northern Hemisphere summer, when the Earth is tilted toward the sun, the Earth's vegetation is able to photosynthesise resulting in an uptake of co2, causing worldwide co2 levels to drop. During winter, when the Earth's axis is tilted away from the sun, the opposite happens causing co2 levels to rise again.When one becomes aware of the correlation between the Earth's vegetation and co2 levels, it is easy to understand why the Amazon, and rainforests in general are such an important part of Earth's ecosystem. If global warming is to be tackled, the Amazon, and other rainforests must be saved

No comments:

Post a Comment