自然平衡英文怎么说

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。那么，自然平衡英文怎么说呢？

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。