Human Impacts: Ugly

       The main human impact on the Amazon Rainforest is deforestation. Humans deforest to create land for small-scale agriculture (subsistence agriculture), large-scale agriculture (commercial agriculture), cattle ranching, and logging. These industries provide people with the resources and food they need to survive. The graph below illustrates the impact each of these industries has on the Amazon Rainforest.

http://rainforests.mongabay.com/0803.htm

   
        As shown in the graph, cattle ranching is the leading cause of deforestation. In 2005, it was responsible for 40% of deforestation, but today the number is closer to 60%. In particular, the Brazilian Rainforest has more than 214,000 square miles of pasture and is the largest exporter of beef. 

        Subsistence agriculture, which accounts for 15-20% of deforestation, is a more sustainable, small-scale method of farming. Farmers typically use the slash-and-burn technique to create fertile land, which is less harmful to the environment. 

       On the other hand, commercial agriculture, which also accounts for 15-20% of deforestation, is executed on large scales and crops are typically planted in monoculture. Monoculture depletes soil fertility more quickly and permanently. These harmful methods have a more detrimental effect on the environment and health of the rainforest. 

       Although logging in the Amazon is supposed to be controlled by strict licensing, illegal logging is very common, making it responsible for 5-8% of deforestation. Additionally, logging is tightly associated with road building, which is another contributing factor of deforestation. The new roads that are built in rain forests uncover previously protected areas, which leads to more logging.
       Other activities that have impacted deforestation include hydroelectric projects, such as the building of dams and mining. Expansions of urban life and infrastructure can also be a cause of uncontrollable fires, which tropical rainforests are not adapted to.

worldwildlife.org/places/amazon