第4章 Balance of Nature自然平衡
自然平衡又称“生态平衡”。在自然界中，无论是森林、草原、湖泊……都是由动物、植物、微生物等生物成分和光、水、土壤、空气、温度等非生物成分所组成。每一个成分都并非是孤立存在的，而是相互联系、相互制约的。它们之间通过相互作用达到一个相对稳定的平衡状态，称为生态平衡。实际上也就是在生态系统中生产、消费、分解之间保持稳定。如果其中某一成分过于剧烈地发生改变，如大量繁殖，都可能出现一系列的连锁反应，使生态平衡遭到破坏。如果某种化学物质或某种化学元素过多地超过了自然状态下的正常含量，也会影响生态平衡。生态平衡是生物维持正常生长发育、生殖繁衍的根本条件，也是人类生存的基本条件。生态平衡遭到破坏，会使各类生物灭绝。
What is the balance of nature
什么是自然平衡
The balance of nature refers to the theory that ecological systems are usually in a stable equilibrium (homeostasis), which is to say that a small change in some particular parameter (the size of a particular population, for example) will be corrected by some negative feedback that will bring the parameter back to its original “point of balance” with the rest of the system. It may apply where populations depend on each other, for example in predator/prey systems, or relationships between herbivores and their food source. It is also sometimes applied to the relationship between the Earth's ecosystem, the composition of the atmosphere, and the world's weather.
The Gaia hypothesis suggests that the Earth and its ecology may act as co-ordinate systems in order to maintain the balance of nature.
The concept has been criticized in recent times as being a pseudoscientific fallacy. It was first put into question when a substantial number of studies showed that predator/prey populations display a continuing state of disturbance and fluctuation rather than constancy and balance. It has been proposed by some scientists that ecological communities of plants and animals are inherently unstable, due to substantial idiosyncratic differences in behavior among communities and individuals in them. An aggressive, dominant wolf for example can greatly increase the chances of a pack in securing food, just as the death of a pack leader can lead to the pack's mass starvation. It is reasoned that any apparent equilibrium is illusory because external factors (such as variations in weather patterns, fires, hurricanes or disease) seldom allow ecological communities to stabilize. Dr. George L. Jacobson Jr., a paleoecologist at the University of Maine stated that according to ancient rock sediments; “there is almost no circumstance one can find where something isn't changing the system. It's never allowed to ‘stabilize’, so we might as well not expect ‘balance’ to exist.”
In addition, some populations show chaotic behavior, where the sizes of populations change in a way that may appear random, but is in fact obeying deterministic laws based only on the relationship between a population and its food source. An example of this was shown in an eight year study on small Baltic Sea creatures such as plankton, which were isolated from the rest of the ocean. Each member of the food web was shown to take turns multiplying and declining, even though the scientists kept the outside conditions constant. An article in Journal Nature stated; “Advanced mathematical techniques proved the indisputable presence of chaos in this food web... short-term prediction is possible, but long-term prediction is not.”
Research into climate change has revealed a number of positive feedback mechanisms that could accelerate any global warming rather than reduce it. These include increased water vapor in the atmosphere (acting as a greenhouse gas); release of Carbon dioxide and methane from melting permafrost; and the decreased ability of warmed oceans to hold carbon dioxide. It is unclear whether negative feedback effects may counter these mechanisms.
Although some conservationist organizations argue that human activity is incompatible with a balanced ecosystem, there are numerous examples in history showing that several modern day habitats originate from human activity: some of Latin America's rain forests owe their existence to humans planting and transplanting them, while the abundance of grazing animals in the Serengeti plain of Africa is thought by some ecologists to be partly due to human-set fires that created savanna habitats.
自然生态系统（natural ecosystem）具有维持自身相对平衡（relative balance）的能力。这种自动调节能力的大小与生态系统的成分（composition）、结构有关。不过，一个生态系统的自动调节能力（self-regulation capability）无论怎样强，也总有一定的限度，如果外来的干扰超过了这个限度，生态平衡就会遭到破坏。破坏自然生态平衡的因素，有自然因素（natural factor）和人为因素（human factor）两类。
自然因素主要指自然界发生的异常变化，或自然界本来就存在的对于人类和生物有害的因素，例如火山爆发（volcanic explosion）、山崩海啸（landslide and tsunami）、水旱灾害（flood and drought）、地震（earthquake）、台风（typhoon）和流行病（epidemic disease）等。人为因素主要指由于人类的活动，造成环境污染（environmental pollution）和自然环境（natural environment）被破坏。
Key words & Sentences
关键词句全知道
The soil contains materials to keep the natural balance of the area.
这些泥土中含有保持该地区大自然平衡的物质。
Forces that can disturb this natural Balance are selection, mutation, gene flow, and natural selection. Certain gene-controlled traits are selected for or against by the partners involved.
能干扰这种自然平衡的外界因素有选择、突变、基因流动以及自然选择。某些受基因控制的性状为与之交配的异性个体所选择或不选择。
People often upset the natural balance by killing off many of the animals and destroying the lands.
人们经常因为杀死过多的动物和毁坏土地而破坏自然平衡。
Every animal has its place in the balance of nature.
在维持自然平衡中，每种动物都有其作用。
In the process, we must be careful about upsetting the balance of nature.
在此过程中，我们必须关注自然平衡的更新进程。
Did Walter equate the balance of nature with God?
沃尔特把自然的平衡和上帝划等号吗？
It is, he says, part of a world wide reaction against technology and an urge to find a better balance with nature.
他说这是在世界范围内逆反技术，并力求跟自然更好地保待一种平衡。
For one thing, law should be forced and observed to keep the balance of the nature by controlling commercial fishing.
首先，法律应该对商业捕鱼加强监督和管制，以保持自然平衡。
Man may destroy the balance of nature, but from time to time, nature takes a terrible revenge for it.
人类可以破坏自然的平衡，但自然会不时地施加可怕的报复。
Efforts are being intensified to prevent or control hazards caused by mice, insects and poisonous weeds, and to maintain the natural ecological balance of the grassland by utilizing scientific means, and artificial and biological technologies.
运用科学手段，采取人工和生物等技术，加大对鼠害、虫害、毒草的预防和治理，维护草地的自然生态平衡。
We should be careful of alteration of the nature in order to balance the natural harmony with our interest.
我们应该关注自然的改变，从而使自然的和谐与我们的利益达到平衡。
Greenpeace spokesperson Ana Rosa Martinez says balance needs to be struck between preserving natural spaces and human activity.
绿色和平组织安娜萝莎玛丁说，在保存自然生态及人类活动中，需要找到一个平衡。
Let's Talk！
开始交流吧！
Monica: Have you heard about the Japanese earthquake?
莫妮卡：你听说日本发生的大地震了吗？
Amanda: Of course, this earthquake generated severe shock to Japan.
阿曼达：当然了，这次地震对日本产生了严重的冲击。
Monica: It is reported that this earthquake lead to the total death of 1500 thousands with an economic loss of more than 235 billion dollars.
莫妮卡：据报道此次地震共造成1.5万人死亡，经济损失超过2350亿美元。
Amanda: What's more, Japanese earthquake has severe effect on global economic development.
阿曼达：不仅如此，日本地震对于全球经济的发展都造成了严重的影响。
Monica: It's terrible.
莫妮卡：真是太可怕了。
Amanda: In recent years earthquake happens frequently around the world, such as Indonesia earthquake in 2004, Wen Chuan earthquake in 2008, Haiti earthquake in 2010 and this one in Japan.
阿曼达：最近几年全球很多国家都频繁发生地震。比如2004年的印尼地震，2008年的汶川地震，2010年的海地地震以及这次的日本地震。
Monica: Not only earthquake, but with many other geological hazards. Such as tsunami happening with earthquake in Japan, the volcanic explosion in Iceland and debris flow in Gan Su province.
莫妮卡：不仅地震频发，还伴随着很多其他地质灾害。比如伴随日本地震发生的海啸、冰岛的火山爆发、甘肃的泥石流等等。
Amanda: These are punishments from the god.
阿曼达：这些都是上帝对人类的惩罚。
Monica: You're so superstitious.
莫妮卡：你太迷信了。
Amanda: I just make a metaphor. In fact these geologic hazards are related with human activities.
阿曼达：我只是作个比喻。实际上这些地质灾害都是和人类的活动有关的。
Monica: Right. Human activities break the ecological balance and lead to natural disasters.
莫妮卡：没错。人类的活动破坏了生态平衡，从而引发了自然灾害。
Amanda: In the past century, every country devoted to the national economic development. While national development requires all kinds of resources, so people used the resources on earth to the largest extent.
阿曼达：在过去的一个世纪中，世界各国都致力于国家的经济发展。而国家的发展需要各种能源，所以人们就最大限度地利用地球上的能源。
Monica: However, in the process of resource utilization, people ignored ecological balance, which lead to the ever-increasing environment pollution.
莫妮卡：然而人们在利用能源的过程中却忽略了生态平衡，环境污染问题日益严重。
Amanda: It is accounted that there are numerous species die out per year due to climate change.
阿曼达：据统计，每年有无数物种因为气候变化而灭亡。
Monica: Human beings and other creatures in nature constitute the ecological system together and mutually dependent on each other, which form a balance. But this balance is broken gradually.
莫妮卡：人和自然界其他生物共同构成了生态系统，彼此互相依赖，形成了一种平衡。但是这种平衡正逐渐被打破。
Amanda: It is unimaginable of the situation when there are only human beings on the earth.
阿曼达：真是难以想象当世界上只有人类的时候会是什么状况。
Monica: This situation won't happen, because people will also die out at that time.
莫妮卡：这种情况不会发生，因为到那个时候人类也将灭亡。