寂静的春天--国际课程作业.doc

寂静的春天各章内容概述：第一章书篇的开张，作者描写了一座宁静的乡村在农民移居这里之后发生可怕地变化，到处蔓延着死亡的气息。第二章讲述了人类对自然地改造的步伐胜过了自然自我修复的步伐，致使地球的生命和环境平衡遭到破坏,指出人们使用杀虫剂已经造成了一些问题，为下文开了个头。第三章讲随着人们频繁大量使用杀虫剂，昆虫会产生抗药性，而使得人们不得不加强杀虫剂药效，如此反复，昆虫并没有因此被消灭，反而使杀虫剂中的有害物质积蓄在植物和动物的组织里危害未来形态的遗传物质。第四章开头谈到淡水资源的缺乏，接着讲杀虫剂通过各种途径渗透到水中，造成水体污染，而水循环恶化扩散了污染，再通过食物链积累循环，使其危害无所不在。第五章从土壤的产生过程、微小生物的腐烂降解作用实现生物圈循环、以及一些生活在土壤里的昆虫（蚯蚓）的作用等方面，说明土壤与生命之间是相互依赖的关系，“生命创造了土壤，而异常丰富多彩的生命物质也生存与土壤之中”，从而形成一个交织的生命网。但是有毒的杀虫剂则会杀害这些有益共生体,破坏土壤的生物平衡，而且这些化学药剂并不会稀疏消失而会长期残留在土壤中，并慢慢积累，越来越多，这些杀虫剂会被土壤上的植被吸收，致使我的食物来源长期受到污染。第六章开头举例鼠尾草与又鸟鼠尾草与尖角羚羊之间相互平衡的自然系统由于人们为达到眼前的利益铲除鼠尾草地，使这个生态系统遭到了破坏，这里的其他生物也跟着消失，土地变得贫瘠。这指出了因消灭鼠尾草而出现的首要的影响。 接着又指出了因其采取的消灭手法喷药枪而带来的更深层次的影响：喷药枪杀死了鼠尾草的同时还一并杀死了其他的植物，进而影响更多的生态系统，人们因此遭受风景及与风景有关的各种利益的无限损失。 接着作者通过金盏草消灭线虫这个例子说明，杂草并不是都无益的，我们不该在尚不了解一些植物是否会对土壤起有益作用之前残忍的将其根除。最后作者提议利用食物链的关系引入相应昆虫以抑制杂草的生长。第七-十章，讲了几个关于杀虫剂使用破坏环境的具体案例。比较通俗易懂。它包括美国中西部为了消灭日本甲虫的大喷洒，为了治理榆树病喷药导致的鸟类灭绝，药剂进入水体导致鱼类的灭绝，为消灭火蚁导致的野生动物灭绝和奶牛体内化学物质富集。第十一章继续在言语上强调农药的危害，以及举了日常生活的几个例子来说明其广泛的危害性，还提到美国的药物管制的不健全，使得杀虫剂被滥用，试图让所有人重视农药被掩盖忽视的具有很大危害的事实。第十二章讲毒素会存储在人类身体的肝脏中，影响肝脏正常功能的发挥，并降低肝脏对疾病的抵抗力引发肝炎肝硬化等肝脏疾病。还指出杀虫剂能直接影响神经系统，患者会出现刺痛、发热、疲劳、四肢疼痛、神经性紧张痉挛等急性中毒症状，及健忘、失眠、做恶梦、癫狂、肌肉萎缩等长期的后遗症的影响。第十三、十四章用大量的生物学知识来论述氯化烃和有机磷酸盐干扰细胞的原理，对线粒体和DNA的破坏和致癌作用，增加了其理论的权威性。第十五章论述昆虫超强的繁殖能力，指出杀虫剂是消灭不了昆虫的，虫灾再消灭几年后又会再次出现，并且更具破坏性。更糟糕的是，杀虫剂的药效并不是选择性的，它除了杀死害虫之外，还会把害虫的天敌一起消灭。并指出有效的昆虫控制需要由自然界来完成，可是只有2%的科学人员在研究生物控制，而剩下的98%都被受聘去研究化学杀虫剂。第十六章讲大量使用杀虫剂的后果是昆虫出现了抗药性，并带来了等大的麻烦。随着昆虫抗药性的不断提高，人们不得不用一种杀虫剂替代另一种杀虫剂，这样无限的继续下去人类会面临死亡的困境。在回答人是否也会产生抗药性的问题上，作者人为人一个世纪只能演化三代，昆虫十几天就是一代，拼杀虫剂，人不可能是昆虫对手。第十七章最后呼吁，我们要做出正确的选择，寻求有效的生物控制的方法，例如用放射性来使昆虫不育；利用昆虫本身的生活特征来制造消灭昆虫的武器：作者举的例子是用吸引剂来迷惑雄蛾，从而改变它的正常行为，干扰其与雌蛾配偶来达到控制繁殖的目的；利用微生物控制昆虫、利用病毒消灭昆虫，昆虫病菌具有专一性，所引发的疾病只局限在昆虫之中，因此不用担心其负面影响；通过引入昆虫的天敌来控制虫灾，作者举出了几个例子说明其可行性。总结：整本书就是在讲杀虫剂的危害，并辅以大量的例子，以今天的角度看，她的文字里充满了感情，同时掩盖了科学性，有一点激进，在当时煽动起了大众不必要的狂热，禁用DDT导致的疟疾肆虐杀死了2000万人。至今仍有许多人质疑它。同时正是这本不寻常的书，在世界范围内引起人们对野生动物的关注，唤起了人们的环境意识，这本书同时引发了公众对环境问题的注意，促使环境保护问题提到了各国政府面前，各种环境保护组织纷纷成立，从而促使联合国于1972年6月12日在斯德哥尔摩召开了“人类环境大会”，并由各国签署了“人类环境宣言”，开始了环境保护事业。在历史的角度讲，这本书是具有革命性的。也有科学家指出，她的书有些危言耸听，比如科学未证实DDT对人体的致癌作用。但是不可否认，这本书确实“There was a strange stillness. The birds, for examplewhere had they gone?” “The feeding stations in the backyards were deserted. The few birds seen anywhere were moribund; they trembled violently and could not fly. It was spring without voices.” “On the farms the hens brooded, but no chicks hatched.” “The roadsides, once so attractive, were now lined with browned and withered vegetation as though swept by fire. These, too, were silent, deserted by all living things. Even the streams were now lifeless.”This is a strange scene described by Rachel Carson, who is regarded as “the mother of modern environmental protection movement”。 Silent Spring is her representative work which lighted the fire of environmental protection in America and the whole world. Before 1960s, no books or magazines talked about things like environment and ecosystem. Such a phenomenon means that environmental protection had not come to peoples mind and the social consciousness. Indeed, the main opinion in human society from the very past about nature is to “set war against” or “conquer” it. In fact, many of humans progresses are made on the base of such opinion. Rachel Carson was the first person who doubted the correctness of the belief and brought the topic under focus.In Silent Spring, Carson described a miserable village which was dying under the using of DDT. The village used to be prosperous and beautiful. “In spring, white clouds of bloom drifted above the green fields. In autumn, oak and maple and birch set up a blaze of color that flamed and flickered across a backdrop of pines. Then foxed barked in the hills and deer silently crossed the fields, half hidden in the mists of the fall mornings.” She thought that with the using of variety kinds of pesticide, especially DDTs, the village suffered enormous and irreversible damage and gradually withered and died. Soon it became just like the one described in the beginning. From her fine and smooth describing, I can even feel the groan of the town. Moreover Carson also sharply pointed out that the deep-seated cause for the environmental problem is the humans arrogance and ignorance. So she asked people to correct the attitude toward the nature and reconsidered the developing path of human being.Carson thought that because of the antibody and differentiation, pesticides would never be completely useful. On the contrary, those more and more poisonous medicines, because of the enrichment effect, would accumulate in humans body. Its quite sarcastic that we hurt ourselves much badly while hurting the others. Then she analyzed many poisonous components in pesticides. Those are all unfamiliar names except DDT, such as chlordane, chloronaphthalene, compound 497, etc.Those things really make me feel scared. We are on the top of the food chain, and it is such a perfect and fragile system. We human beings are just part of it and we depend on all of the creatures who stay on the lower positions. It is so hard and ridiculous to try to match the nature. ”Only in the state does man have a rational existence.” Every species have their value to be on this world. Then no one knows what would happened if we force them to disappear. For example, lets imagine the food chain as a meticulously made castle built by billions of little blocks and we human beings are the top one. There might be several tiny blocks on the bottom which you think is useless and dispensable. But what would happen if we take them away? Perhaps nothing happened, and perhaps the whole castle ruined.Destruction is always much easier than recovery, not counting those incurable ones. Humans always think that we are much cleverer than the other animals, so we become more and more conceited and firmly believe that we are the king. We didnt see that the nature is so magical and knows how to revenge. The pay back is much more violent and cruel. We need balance and order. The nature has its own rule. Our aim is to use it and live in harmony with it. The ecosystem is so delicate that even a tiny disturbance could lead an unexpected consequence, just like the butterfly effect.At the last chapter, some scientists came up with other ways to solve the pest problem-biotic control. There is now a strongly running tide of interest in chemical sterility. Those sterile insects are released and mate the normal ones so that they wont have any larva and get extinct gradually. This “solution” seems to be reasonable and helpful, but thinking about it carefully, youll find that it is just another way to ruin the food chain castle. Not only spring, but also summer and autumn would be still and silent in the future.It is lucky that Rachel still kept her mind clear. She didnt agree with the way of conquering the nature. At the very end of the book, she wrote, “The control of nature is a phrase conceived in arrogance, born of the Neanderthal age of biology and philosophy, when it was supposed that nature exists for the convenience of man.” This sentence can be regarded as the books theme topic which is widely quoted in all kinds of articles ab