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Deforestation of the Amazon rainforest accelerated significantly between 1991 and 2004, reaching an annual forest loss rate of 27,423 km² in 2004. Though the rate of deforestation has been slowing since 2004 (with re-accelerations in 2008 and 2013), the remaining forest cover continues to dwindle.〔 The Amazon rainforest represents over half of the planet's remaining rainforests, and comprises the largest and most biodiverse tract of tropical rainforest in the world. 60% of the forest is contained within Brazil, followed by Peru with 13%, Colombia with 10%, and with minor amounts in Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana. The cattle sector of the Brazilian Amazon, incentivized by the international beef and leather trades,〔Lucy Siegle (August 9, 2015). ("Has the Amazon rainforest been saved, or should I still worry about it?" ) ''The Guardian''. Retrieved on October 21, 2015.〕 has been responsible for about 80% of all deforestation in the region,〔 or about 14% of the world’s total annual deforestation, making it world's largest single driver of deforestation.〔 By 1995, 70% of formerly forested land in the Amazon, and 91% of land deforested since 1970, had been converted to cattle ranching.〔 Much of the remaining deforestation within the Amazon has resulted from farmers clearing land for small-scale subsistence agriculture〔 or mechanized cropland producing soy, palm, and other crops.〔 ==History== In the pre-Columbian era, parts of Amazonas were a densely populated open agricultural landscape. After the European invasion in the 16th century, with the hunt for gold, Western diseases, slavery and later and the rubber boom, Amazonas was depopulated and the forest grew larger.〔Romero, Simon (January 14, 2012) (Once Hidden by Forest, Carvings in Land Attest to Amazon’s Lost World ). New York Times〕 Prior to the 1970s, access to the forest's largely roadless interior was difficult, and aside from partial clearing along rivers the forest remained intact. Deforestation accelerated greatly following the opening of highways deep into the forest, such as the Trans-Amazonian highway in 1972. In parts of the Amazon the poor soil had made plantation-based agriculture unprofitable. The key turning point in deforestation of the Brazilian Amazon was when colonists began to establish farms within the forest during the 1960s. Their farming system was based on crop cultivation and the slash-and-burn method. However, the colonists were unable to successfully manage their fields and the crops due to the loss of soil fertility and weed invasion due to this method.〔Watkins and Griffiths, J. (2000). Forest Destruction and Sustainable Agriculture in the Brazilian Amazon: a Literature Review (Doctoral dissertation, The University of Reading, 2000). Dissertation Abstracts International, 15–17〕 In indigenous areas of the Peruvian Amazon, such as the Urarina's Chambira River Basin,〔Dean, Bartholomew 2009 ''Urarina Society, Cosmology, and History in Peruvian Amazonia'', Gainesville: University Press of Florida ISBN 978-0-8130-3378-5 ()〕 the soils are productive for only relatively short periods of time, therefore causing indigenous horticulturalists like the Urarina to move to new areas and clear more and more land.〔 Amazonian colonization was ruled by cattle raising because ranching required little labor, generated decent profits, and awarded social status in the community. Additionally, grass is able to grow in the poor Amazon soil. However, the abundance of cattle ranching led to extensive deforestation, causing extensive environmental damage. An estimated 30% of the deforestation is due to the actions of small farmers. Although small farmers possess smaller total land area than medium and large ranchers, who possess 89% of the Legal Amazon's private land, the intensity of deforestation within the areas that they inhabit is greater than that within the areas occupied by the larger ranchers. This emphasizes the importance of using previously cleared land for agricultural use, rather the typically easier political path of distributing still-forested areas. In the Brazilian Amazon, the proportion of small farmers to large landholders changes frequently with economic and demographic pressures. In 2009, Peruvian President Alan García pushed through by executive decree Law 840〔Polk, James (April 14, 2009). ("Time to Strengthen Ties with Peru" ). ''Foreign Policy In Focus''.〕 (also known as "Ley de la Selva," "the Law of the Jungle" or simply the "Forest Law"), which allowed the sale of uncultivated Amazon land under state ownership to private companies, without term limits on the property rights.〔Vittor, Luis (January 30, 2008). ("The law of the jungle, to sell the Amazon basin" ). ''Agencia Latinoamericana de información''.〕 While the law was promoted as a "reforestation" measure, critics claimed the privatization measure would in fact encourage further deforestation of the Amazon,〔("Peru: Government intent on privatizing the Amazon for implementing tree plantations" ). ''World Rainforest Movement'', Bulletin 129. April 2008.〕 while surrendering the nation's rights over natural resources to foreign investors and leaving uncertain the fate of Peru's indigenous people, who do not typically hold formal title to the forestlands on which they subsist.〔〔Salazar, Milagros (February 5, 2008). ("ENVIRONMENT-PERU: 'For Sale' Signs in Amazon Jungle" ). ''Inter Press Service''.〕 Law 840 met widespread resistance and was eventually repealed by Peru's legislature for being unconstitutional.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Deforestation of the Amazon rainforest」の詳細全文を読む スポンサード リンク
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