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Deforestation is a major threat to biodiversity and ecosystems in Costa Rica. The country has a rich biodiversity with some 12,000 species of plants, 1,239 species of butterflies, 838 species of birds, 440 species of reptiles and amphibians, and 232 species of mammals, which have been under threat from deforestation.〔(【引用サイトリンク】title=Costa Rica )〕 ==Causes and effects== Deforestation in Costa Rica has a serious impact on the environment and therefore may directly or indirectly contribute to flooding, desertification, sedimentation in rivers, loss of wildlife diversity, and the obvious sheer loss of timber. Since the end of World War II, approximately 80% of the forests of Costa Rica have disappeared.〔(【引用サイトリンク】title=Deforestation-Reforestation )〕 Approximately of land are deforested annually; in the 1990s the country had one of the worst deforestation rates in Central America.〔(【引用サイトリンク】title=Deforestation )〕 As the population grew, the people of Costa Rica cut down the forests to provide for pastureland for cattle ranching to produce beef for the world market to raise revenue. Since the 1950s, approximately 60% of Costa Rica has been cleared to make room for cattle ranching.〔 The problem was worsened because during the 1960s, the United States offered Costa Rican cattle ranchers millions of dollars in loans to produce beef.〔 The deforestation of Costa Rica's tropical rain forests as in other countries is a threat to life worldwide with a profound effect on the global climate.〔 Soil erosion has increased with deforestation with the topsoil washed away from the hills into the streams and out into the oceans, year after year.〔 Over half of Costa Rica's existing forest cover today is under the protection of national parks, biological reserves, or wildlife refuges. However, the major problem in regards to deforestation is the privately owned plots which occupy the other half.〔 Lenient laws on land and amendments to forestry law makes it easy to obtain logging concessions as owners exploit the land to maximise income.〔 As logging companies enter these forests to exploit them, they require access roads to transport the timber. While cattle ranching is by far the primary cause of deforestation in Costa Rica, banana plantations have also significantly contributed to the problem. Lowland rainforest has been most affected where of previously forested land (primarily in the Atlantic and Northern regions) have been removed.〔 Such industries have been synonymous with health risks, notably the high levels of toxic pesticides which affected thousands of plantation workers throughout Central America in the 1970s.〔 Pesticides used to grow bananas and other fruits such as mangoes and citrus fruit may enter the hydrological systems and contaminate the water. The removal of the forest to make way for these fruit planatations may also disrupt the nutrient balance in the soil and through monoculture exhaust the soils and render them unsustainable.〔 Although most of the larger plantations in Costa Rica are owned by large companies, often multinationals, population pressure in Costa Rica has increased the demand for land among farmers who are forced to venture out onto new land to deforest and farm and compete over scraps of land.〔 While certain conservation laws have been passed in Costa Rica, the government lacks the resources to enforce them.〔 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 in Costa Rica」の詳細全文を読む スポンサード リンク
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