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Wednesday, July 9, 2008

deforestation

my sketches



i have decided to choose this sketch as the symbol of my main topic that is deforestation. even though, it looks too simple but there is a meanings behind this symbol.















this are my sketches(O_o). not 'perfect' but 'simple'(^_^). well, i chose a tree as my symbol for global warming because my main topic is deforestation. deforestation is one of the causes of global warming. i got this ideas from some pictures that i found in photobucket.com. so, i try to make it more simple and nice to be view.




















deforestation

The process of destroying a forest and replacing it with something else. The term is used today to refer to the destruction of forests by human beings and their replacement by agricultural systems. Moreover, thecutting down and removal of all or most of the trees in a forested area. Deforestation can erode soils, contribute to desertification and the pollution of waterways, and decrease biodiversity through the destruction of habitat.





causes

There are many causes, ranging from slow forest degradation to sudden and catastrophic clearcutting, slash-and-burn, urban development, acid rain, and wildfires. Deforestation can be the result of the deliberate removal of forest cover for agriculture or urban development, or it can be a consequence of grazing animals, primarily for agriculture. In addition to the direct effects brought about by forest removal, indirect effects caused by edge effects and habitat fragmentation can greatly magnify the effects of deforestation.
While
tropical rainforest deforestation has attracted most attention, tropical dry forests are being lost at a substantially higher rate, primarily as an outcome of slash-and-burn techniques used by shifting cultivators. Generally loss of biodiversity is highly correlated with deforestation.



effects

generally, the removal or destruction of significant areas of forest cover has resulted in a degraded environment with reduced biodiversity. In many countries, massive deforestation is ongoing and is shaping climate and geography.
Deforestation affects the amount of water in the soil and groundwater and the moisture in the atmosphere. Forests support considerable
biodiversity, providing valuable habitat for wildlife; moreover, forests foster medicinal conservation and the recharge of aquifers. With forest biotopes being a major, irreplaceable source of new drugs (like taxol), deforestation can destroy genetic variations (such as crop resistance) irretrievably.