People and the Environment

Tropical rainforests cover over an area of nearly 3 billion acres, or about 8.3 percent of the Earth’s total land surface. These remarkable forests are shared by some 50 countries on five continents. Biologists believe that rainforests are the home of perhaps half the world’s biotic species, about five-sixths of which have not yet been described and named.

Throughout most of history, rainforests were considered to be remote, inaccessible, unpleasant places, and as a result they were little affected by human activities. In the present century, however, rainforests have been exploited and ruined at a quickening pace, and in the last decade or so, tropical deforestation has become one of the Earth’s most serious environmental problems. The rate of deforestation is spectacular — 51 acres per minute; 74,000 acres per day; 27 million acres per year. More than half of the original African rainforest is now gone; about 45 percent of Asia’s rainforest no longer exists; the proportion in Latin America is approaching 40 percent.

    As the forest goes, so goes its animal life. In the mid-1980s it was calculated that tropical deforestation was responsible for the extinction of one species per day; by 1990 it is estimated that the rate was one species per hour.   

Moreover, loss of the forests contributes to increased soil erosion, drought, flooding, worsening water quality, declining agricultural productivity, and greater poverty for rural inhabitants. In addition, atmospheric carbon dioxide continues to be increased because there are fewer trees to absorb it and because burning of trees for forest clearing releases more to the air.

    The irony of tropical deforestation is that the anticipated economic benefits are usually illusory. Much of the forest clearing, especially in Latin America, is in response to the social pressure of overcrowding and poverty in societies where most of the people are landless. The governments open up “new lands” for settlement in the rainforest. The settlers clear the land for crop growing or livestock raising. The result almost always is an initial one or two years of high soil productivity, followed by poor years as fertility declines and the soil begins to suffer from erosion.

The forests, of course, are renewable. If left alone by humans, they can regenerate, as long as there are seed trees in the neighborhood and the soil has not lost all its nutrients. The loss of biotic diversity, however, is much more serious. Extinction is an irrecoverable process. Valuable potential resources may disappear before they are even discovered. Natural genotypes that could be combined with agricultural crops or animals to resist disease, insects, parasites, and other environmental stresses may also be lost. Last, but not least, is the possibility that many small, isolated valuable groups of native people may be wiped out.

    Much concern has been expressed about tropical deforestation, and some concrete steps have been taken. The development of agroforestry (planting crops with trees, rather than cutting down the trees and replacing them with crops) is being fostered in many areas. In Brazil, which has by far the largest expanse of rainforest, some 46,000 square miles of reserves have been set aside, and Brazilian law requires that any development in the Amazon region leave half of the land in its natural state. In 1985 a comprehensive world plan, sponsored by the World Bank, the World Resources Institute, and the United Nations Development Programme, was introduced. It proposes concrete, country-by-country strategies to combat tropical deforestation. It is an $8 billion, fiveyear project, dealing with everything concerning the protection of rainforests.

Meanwhile, the sounds of the axe and the chain-saw and the bulldozer continue to be heard throughout the tropical forest lands.

Reading Comprehension

1. In the past, rainforests were nearly left intact because                  
［A］ people then had a better sense of environmental protection

［B］ people then knew better how to protect them

［C］ people then looked at rainforests in some awe

 ［D］ people then did not know how to exploit them

2. Which of the following is NOT mentioned as a result of deforestation?

［A］ Loss of species diversity.

［B］ Increased poverty for the concerned countries. 

［C］ Increased atmospheric pollution.

［D］ Loss of culture diversity.

3. It can be inferred from the passage that forest destruction mainly results from                  .

［A］ people’s desire to meet their economic needs

  ［B］ people’s ignorance of the importance of forests to biotic species

［C］ people’s need to burn fuel to warm their homes

［D］ people’s desire to open up more farmland

4. People’s attempt to clear the forest to open up new lands often has the result of                .

［A］ leaving even more people homeless

［B］ expanding settlement but destroying  the land

［C］ finding more land for landless people to cultivate

［D］ renewing the forest at a slower pace

5. The tone of the author餾 conclusion seems to be                    .

［A］ optimistic             ［B］ objective         

［C］ concerned             ［D］ tolerant

【答案与题解】

 

1.［C］意为：人们当时用敬畏的眼光看待热带雨林。

 

  参阅第二段第一句。

 

2.［B］意为：使相关国家更贫困。

 

第四段第一句只提到了给农村居民(rural inhabitants)带来的贫困状况。

 

有关［A］参阅第三段和第六段，有关［C］参阅第四段第二句，有关［D］参阅第六段最后一句。

3.［A］

  参阅第五段第一、二、三、四句。相比较而言，［D］表达的意思则有些片面。

4.［B］意为：扩展了定居点，但毁坏了土地。

  参阅第五段。

 

5.［C］意为：关注。

 

  参阅最后一段。

 

Notes
1.第四段第二句是一个简单主从复合句。句架是...carbon dioxide continues to be increased because there are...and because burning of trees...releases more to the air。to absorb it 中的 it 指carbon dioxide；releases more to the air 中的 more 指 more carbon dioxide；forest clearing 是“森林空地”的意思。

2.第五段第二句中in response to的字面意思是“对……做出反应”。

 

3.第七段第三句是一个并列主从复合句。句架是some...miles of...have been set aside and Brazilian law requires that...。句首which引导的非限制性定语从句修饰Brazil；句中that引导的名词从句是require的宾语从句，因而宾语从句中的leave是以虚拟语气的形式出现，即主语是第三人称单数时态，谓语动词也不加“s”。句中expanse作“大片地区”讲；by far是“最”的意思。

课文参考译文

人 与 环 境

热带雨林所占面积将近30亿英亩以上，即约占地球陆地表面总面积的8.3％。这些引人注目的森林为五大洲的约50个国家所共有。生物学家认为这些雨林或许是世界一半生物种的生息地，其中约5/6尚未被记述过，也没有被命名过。

在历史的大部分时间里，雨林被认为是遥远的、无法接近的和令人不愉快的地方，结果没有受到人类活动的影响。但是在目前这个世纪，雨林被以逐步加快的速度开采和毁坏，在过去10年左右时间，对热带雨林的滥伐已成为地球上最严重的环境问题之一。对热带雨林的滥伐速度是惊人的——每分钟51英亩；每天74 000英亩；每年2 700万英亩。非洲原始雨林一半以上现在已不复存在；亚洲雨林约45％已不再存在；拉丁美洲的雨林现在所占比例接近40％。

森林消失，动物的生命也随之消失。据估算，在20世纪80年代中期，对热带雨林的滥伐造成每天消失一个物种；到1990年，则变为每个小时消失一个物种。

此外，森林消失导致水土流失加剧、干旱、洪涝、水质不断恶化、农业生产率不断下降和农村居民更加贫困。另外，由于吸收二氧化碳的树木减少，也由于烧林造地把更多的二氧化碳释放到空气中，因此大气中的二氧化碳继续增多。

热带雨林遭受滥伐的讽刺意味在于，预期中的经济好处通常是虚假的。大部分森林空地，尤其是拉丁美洲的森林空地，是作为对人过于拥挤的社会压力和大部分人没有土地的社会贫穷现象的反应而出现的。一些政府在雨林中为移民开辟“新土地”。移民开辟土地用于种植作物，或饲养牲畜。结果几乎总是最初一两年土壤生产率高，随后几年就会由于肥力下降和土壤开始受到水土流失的影响而收成欠佳。

森林当然是能再生的。如果人类不干扰森林，只要附近有母树，而且土壤没有丧失全部营养，森林就能再生。然而失去生物多样性则严重得多。物种的灭绝是不可挽回的过程。宝贵的潜在资源甚至可能在被发现之前就已消失。可能与农作物或动物结合在一起抵抗疾病、昆虫、寄生虫和其他环境压力的天然基因型也可能丢失。最后但并非最不重要的是，许多与世隔绝的、重要的小土著群体可能被消灭。

人们对热带雨林遭到滥伐已表示非常担忧，并且采取了一些具体措施。许多地区鼓励发展农业造林(与种树一起播种作物，而不是在砍树后种作物)。在雨林面积最大的巴西，已经留出了46 000平方英里的保护区，而且巴西的法律要求亚马孙河地区的任何开发项目都要把一半的地区保留在自然状态。1985年，在世界银行、世界资源学会和联合国开发计划署倡议下制定了一项全面的全球计划。这个计划建议各国都要制定具体的反对毁坏热带雨林的战略。这是一项耗资80亿美元的5年计划，涉及保护雨林的一切事项。

与此同时，在整个热带森林的土地上仍在继续听到斧头、链锯和推土机的响声。

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