1、B3U1 Nature in the balance1Reading 2The Amazon rainforest:a natural treasure3456 亚马孙热带雨林（Amazon Rain Forest）位于南美洲的亚马孙平原，占地550万平方公里。雨林横越了9个国家：巴西（占森林60%面积）、哥伦比亚、秘鲁、委内瑞拉、厄瓜多尔、玻利维亚、圭亚那、苏里南以及法国（法属圭亚那），占据了世界雨林面积的一半，占全球森林面积的20%，是全球最大及物种最多的热带雨林。亚马孙雨林被人们称为“地球之肺”和“绿色心脏”，“世界动植物王国”等。亚马孙流域的热带雨林大半位于巴西。这里雨量充沛，加上安第
2、斯山脉冰雪消融带来大量流水，每年有大部分时间为洪水淹没。雨林几乎全年闷热潮湿，日间气温约33C，夜间气温约23C。它从安第斯山脉低坡延伸到巴西的大西洋海岸。亚马孙雨林对于全世界以及生存在世界上的一切生物的健康都是至关重要的。这片森林对世界气候有很大影响，树林能够吸收二氧化碳，二氧化碳这种气体的大量存在使地球变暖，以至极地冰盖融化，引起洪水泛滥。树木也产生氧气，它是人类及所有动物的生命所必需的。7 亚马孙雨林产生的氧气占全球氧气总量的1/10。木材占全世界木材总蕴藏量的45%。生物物种占全世界总数的1/5，植物种类和鸟类各占世界的一半，淡水资源占世界总量的18%。亚马孙平原的野生动物种类非常繁多
3、，而且数量丰富。共有14712种动物，其中8 000多种尚未为人所知，现在已知的动物和鸟类超出了10万种，可能另外还有几百万种正等待着人们去发现。因此，亚马孙河流域对全球气候和生态环境的影响是举足轻重的。由于开发不当和保护不利，巴西的亚马孙雨林正在遭到严重的破坏，正以惊人的速度减少，森林覆盖率已从原来的80%减少到58%，专家们说，这种情况对物种保护和全球气候的平衡有可能构成威胁。造成森林大面积减少的原因首先是近年来大量移民涌入亚马孙地区，造成农业耕地紧缺，因此毁林造田现象十分普遍。此外，由于缺乏有效的管理，无序采矿、修路、建房是造成大面积伐林的另一原因。与此同时，人为或自然因素引发的大火也使
4、森林面积不断减少。面对严峻局面，反对乱砍滥伐森林的呼声日渐强烈。8ABBAC9CDRead the text and choose the best answer:10BAD11Para.1:Para.2:Para.3:.Pare.4:.Para.5:.Plants of the Amazon rainforest.Birds and animals of the Amazon rainforest.The summary of the Amazon rainforest.Read the documentary script and write the main idea of each p
5、aragraph.(P4)Introduction to the Amazon rainforestBasic information about the rainforest12Read the documentary script again carefully and fill in the blanks with the figures.(P4)86 million640040,000130040020%1713 The status of The Amazon rainforset:_.The Amazon rainforest lies on_.It named after _.T
6、he Amazon rainforest and the Amazon River give the _ _on the earth.the largest rainforest in the worldthe South American continentThe Amazon Riverrichest biodiversityParas 1-2:Introduction14brazil nut;water liliesThere are levels of plant species.At the bottom:_Above:_The next level is._Then._roots
7、leaf littershorter plants with larger leavestowering and ancient hardwoods4Para 3:Plants151,300 species of birds;over 400 species of mammalsThe jaguars feed on .at least 87 speciesinsectsleaves and fruitmicroorganismsnutrients Para 4:Animals161.Why does the Amazon rainforest play a significant role
8、in maintaining the balance of the Earths ecosystem?2.Can we afford to damage the“lungs of the planet”?the“lungs of the planet”a treasure house of speciesfood and medicine materialsPara 5:Importance and danger171.What makes the Amazon rainforest a natural treasure according to the script?2.Are there
9、any places in China with rich biodiversity like the Amazon rainforest?What are they?Introduce one to the class.Discussion18Text analysis19Welcome to the jungle,a huge sea of green alive with the sounds of animals.This is the Amazon rainforest.As the largest rainforest in the world,it plays a signifi
10、cant role in maintaining the fine balance of the Earths ecosystem.20 The Amazon rainforest crosses into eight countries,including Brazil and Peru,and one overseas region of France,all on the south American continent.With an area of around 6 million square kilometers,the Amazon rainforest is more tha
11、n half the size of China.21The Amazon river,from which the rainforest gets its name,is close to 6,400 kilometers in length-roughly 100 kilometers longer than the Yangtze River.On its journey from the mountains to the ocean,the river supports many different ecosystems.They give this area the richest
12、biodiversity on the earth:one in ten known species in the world can be found here.22Of the 390,000 plant species known to us,more than 40,000 can be found in the Amazon.This tall and ancient brazil nut tree produces nuts that we can eat;these water lilies are big enough to lie down on.The forests di
13、fferent levels support an unbelievable variety of wildlife.At the bottom,there is a system of roots beneath the ground.23Above that is the mass of leaf litter on the dark forest floor.The next level is made up of shorter plants with large leaves.Then there are the towering ancient hardwoods,and fina
14、lly the tops of the tallest trees many meters above the ground.Each level of the forest forms its own little world,home to different kinds of living things.24More than 1,300 species of birds and over 400 species of mammals hide among the jungles plant life.This jaguar is one example.It has a yellowi
15、sh-brown coat with black spots.While a significant number of jaguars survive here,they are only one element of this forests food chain.They feed on at least 87 species,including frogs.These frogs,in turn,feed on insects which eat leaves and fruit.When a jaguar dies,a tiny army of microorganisms help
16、s break down its body and return the nutrients to the earth.25The Amazon rainforest breathes life into the planet by fixing carbon and producing over 20 per cent of all the Earths oxygen.Thus,it is often known as the“lungs of the planet”.Moreover,the Amazon rainforest is a treasure house of species
17、that can be used for food or medicine.Yet there is one major danger to these irreplaceable plants and animals:us.26Over the past 50 years,about 17 per cent of the rainforest has disappeared due to human activities such as agriculture and cattle farming.As the impact of human activities continues to
18、grow and the list of species in danger of extinction becomes longer,we are left with a question:can we afford to damage the“lungs of the planet”?27varietyPart B1 on P5agriculturesurviveimpactdue tobreak downbeneaththus28unimportant;unfit;unwell;unfriendlyPart B2 on P5dislike;disabled;disagreeincorrect;inconvenient;impossible;illegal;irregularnonverbal;nonfat;29Thanks30
