Monday, August 2, 2010
DEFORESTATION. Deforestation is the conversion of forested areas to non-forested areas. The main sources of deforestation in the Amazon are human settlement and development of the land. Prior to the early 1960s, access to the forest´s interior was highly restricted, and the forest remained basically intact. Farms established during the 1960s were based on crop cultivation and the slash and burn method. However, the colonists were unable to manage their fields and the crops because of the loss of soil fertility and weed invasion. The soils in the Amazon are productive for just a short period of time, so farmers are constantly moving to new areas and clearing more land. These farming practices led to deforestation and caused extensive environmental damage. Deforestation is considerable, and areas cleared of forest are visible to the naked eye from outer space. Between 1991 and 2000, the total area of forest lost in Amazon rose from 415,000 to 587,000 square kilometres, with most of the lost forest becoming pasture for cattle.
In addition, Brazil is currently the second-largest global producer of soybeans after the United States. The needs of soy farmers have been used to validate many of the controversial transportation projects that are currently developing in the Amazon. The first two highways successfuly opened up the rain forest and led to increased settlement and deforestation. At the current rate, in two decades the Amazon Rainforest will be reduced by 40%.
CONSERVATION AND CLIMATE CHANGE.
Environmentalists are concerned about loss of biodiversity that will result from destruction of the forest, and also about the release of the carbon contained within the vegetation, which could accelerate global warming. Amazonian forests are estimated to have accumulated 0.62 = 0.37 tons of carbon per hectare (a little over 2 acres) per year between 1975 and 1996.
One computer model of future climate change caused by greenhouse gas emissions shows that the Amazon rainforest could become unsustainable under conditions of severely reduced rainfall and increased temperatures, leading to an almost complete loss of rainforest cover in the basin by 2100. However, simulations of Amazon basin climate change across many different models are not consistent in their estimation of any rainfall response, ranging from weak increases to strong decreases. The result indicates that the rainforest could be threatened through the 21st century by climate change in addition to deforestation.
From 2002 to 2006, the conserved land in the Amazon Rainforest has almost tripled and deforestation rated have dropped up to 60%. About 1,000,000 square kilometres (250,000,000 acres) have been put onto some sort of conservation, which adds up to a current amount of 1,730,000 square kilometres (430,000,000 acres). It is safe to say that the Amazon Rainforest will eventually perish and develop into a savannah five million years in the future even if all human deforestation activity ceased permanently.
IMPACT OF AMAZON DROUGHT.
In 2005, parts of the Amazon basin experienced the worst drought in one hundred years, and there were indications that 2006 could have been a second successive year of drought. A 23 July 2006 article in the U.K. Newspaper "The Independent" reported Woods Hole Research Center results showing that the forest in its present form could survive only three years of drought. Scientists at the Brazilian National Institute of Amazonian Research argue in the article that this drought response, coupled with the effects of deforestation on regional climate, are pushing the rainforest towards a "tipping point" where it would irreversibly start to die. It concludes that the forest is on the brink of being turned into savannah or desert, with catastrophic consequences for the world´s climate. Even if all human activity that negatively affects the health and stability of the Amazon rainforest should cease permanently, the rainforest will eventually destroy itself and become a savannah after five million years. According to the World Wide Fund for Nature, the combination of climate change and deforestation increases the drying effect of dead trees that fuels forest fires.
Thank you for reading!!