Succession, Climax, and Ecosystems
In the late nineteenth century, ecology began to grow into an independent science from its roots in natural history and plant geography. The emphasis of this new ‘community ecology’ was on the composition and structure of communities consisting of different species. In the early twentieth century, the American ecologist Frederic Clements pointed out that a succession of plant communities would develop after a disturbance such as a volcanic eruption, heavy flood, or forest fire. An abandoned field, for instance, will be invaded successively by herbaceous plants (plants with little or no woody tissue), shrubs, and trees, eventually becoming a forest. Light-loving species are always among the first invaders, while shade-tolerant species appear later in the succession.
生态学开始变成独立的学科 。这个新的社会生态的重点在包含了各个不同种类的社会的组合和结构。一个美国生态学家FC指出一连串植物社群在受到扰动后将会发展。一个富裕的地区将会被草本植物一连串的入侵，最后变成森林。喜光的种类总是第一批入侵者，但是忍受阴影的物种将会在后面连续出现
Clements and other early ecologists saw almost lawlike regularity in the order of succession, but that has not been substantiated. A general trend can be recognized, but the details are usually unpredictable. Succession is influenced by many factors: the nature of the soil, exposure to sun and wind, regularity of precipitation, chance colonizations, and many other random processes.
FC和其他早期生态学家看到了几乎按顺序排列的规则。一个大题的趋势可以被分辨，但是这些细节经常不能被预测。这个过程通常被很多因素给影响：。。。。
The final stage of a succession, called the climax by Clements and early ecologists, is likewise not predictable or of uniform composition. There is usually a good deal of turnover in species composition, even in a mature community. The nature of the climax is influenced by the same factors that influenced succession. Nevertheless, mature natural environments are usually in equilibrium. They change relatively little through time unless the environment itself changes.
这个过程的最后阶段同样也是不可预测 或均匀组成的。即使在成熟的社群里，也有物种的转换。这个自然社群的巅峰被相同的因素所影响。虽然如此，成熟的自然环境通常是平衡的。他们变化的相对较小
For Clements, the climax was a ‘superorganism,’ an organic entity. Even some authors who accepted the climax concept rejected Clements’ characterization of it as a superorganism, and it is indeed a misleading metaphor. An ant colony may be legitimately called a superorganism because its communication system is so highly organized that the colony always works as a whole and appropriately according to the circumstances. But there is no evidence for such an interacting communicative network in a climax plant formation. Many authors prefer the term ‘association’ to the term ‘community’ in order to stress the looseness of the interaction.
Even less fortunate was the extension of this type of thinking to include animals as well as plants. This resulted in the ‘biome,’ a combination of coexisting flora and fauna. Though it is true that many animals are strictly associated with certain plants, it is misleading to speak of a ‘spruce-moose biome,’ for example, because there is no internal cohesion to their association as in an organism. The spruce community is not substantially affected by either the presence or absence of moose. Indeed, there are vast areas of spruce forest without moose. The opposition to the Clementsian concept of plant ecology was initiated by Herbert Gleason, soon joined by various other ecologists. Their major point was that the distribution of a given species was controlled by the habitat requirements of that species and that therefore the vegetation types were a simple consequence of the ecologies of individual plant species.
幸运的是这种观点的包括动物和植物的延伸。这导致了BIOME，一个动物群和植物群同时存在的结合。虽然很多动物和某些植物紧紧关联是事实，但是单论SMBIOME是具有误导性的。因为在链接中没有内聚力力，云山社群不被其他moose的存在所影响。的确存在大片云杉森林没有moose。与C的植物生态内容理论相反的理论被HG提出，有其他很多生态学家支持。这个理论主要指出存在物种的分布被这些物种栖息地的要求所控制，因此草本植物的类型是个体植物生态的简单结果
With ‘climax,’ ‘biome,’ ‘superorganism,’ and various other technical terms for the association of animals and plants at a given locality being criticized, the term ‘ecosystem’ was more and more widely adopted for the whole system of associated organisms together with the physical factors of their environment. Eventually, the energy-transforming role of such a system was emphasized. Ecosystems thus involve the circulation, transformation, and accumulation of energy and matter through the medium of living things and their activities. The ecologist is concerned primarily with the quantities of matter and energy that pass through a given ecosystem, and with the rates at which they do so.
“ecosystem”这个属于越来越被广泛接受。最终这个系统的能量转化的作用被强调重视。因此生态系统包括循环，转化，能量的聚集，同时通过中间生物和他们的活动来发挥作用。生态学家担心matter的数量和能量。
Although the ecosystem concept was very popular in the 1950s and 1960s, it is no longer the dominant paradigm. Gleason’s arguments against climax and biome are largely valid against ecosystems as well. Furthermore, the number of interactions is so great that they are difficult to analyze, even with the help of large computers. Finally, younger ecologists have found ecological problems involving behavior and life-history adaptations more attractive than measuring physical constants. Nevertheless, one still speaks of the ecosystem when referring to a local association of animals and plants, usually without paying much attention to the energy aspects.
虽然生态学内容在1950-1960非常受欢迎。但是它不再是主流范例。G的言论很大程度上有效的反驳了生态学的内容。甚至，相互作用的 数量太多了很难去分析。最后年轻生态学家发现包含了行为和历史生命适应性生态学问题比衡量物理接触更加有吸引力。当说到当地动植物的联系，有的人依旧会谈到生态学。
disturbance 弄乱// 打扰// 骚扰。同义词： ado ballyhoo bluster bother
succession 连续// 一连串//继承，继承权
successive 连续的。同义词： back-to-back consecutive sequent
clement 和煦的 仁慈的
Substantiate v 证明 // 证实 同义词：demonstrate establish prove
substantial 可观的 // 相当的 // 大体上的 // 重要的//满的//稳定的
同义词：REAL TRUE FULL STURDY CONSEQUENTIALLY EVENTFUL
precipitation 沉淀 // 降水
uniform n 制服 校服 // adj 均匀的 相同的。不变的 同义词：even invariant unchanging
turnover 营业额 //转化率
equilibrium 均衡//平衡//平静 adj 同义词 balance counterpoise
entity 实体 n
metaphor 影遇 比喻说法 象征
colony ：殖民地 //有相同的特点的人群 //聚居桥名 // 群体 （一群蚂蚁）
fortunate 幸运的 吉利的。同义词： fluky // fortuitous
flora and fauna 植物群和动物群
cohesion 团结//一致性//完整性//内聚力 unity union
vegetation. 植被//无所事事
paradigm 范例 n
constant adj：持续的//反复的//不变的//忠实的 n:常数//恒量//不变的事物
spruce
