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托福阅读：植物“殖民主义”​

2016-04-25 17:15:56来源：网络

　　P2: Both the rate of invasion and the rate of extinction vary greatly among different plant species. Pioneer species – those that occur only in the earliest stages of colonization - tend to have high rates of invasion because they produce very large numbers of reproductive propagules (seeds, spores, and so on) and because they have an efficient means of dispersal (normally, wind)

　　难词解析：

　　extinct: v.灭绝

　　efficient：adj.有效率的

　　means：n.手段，方法;财富

　　disperse： v. 散开

　　难句解析：

　　Pioneer species – [those that occur only in the earliest stages of colonization] - tend to have high rates of invasion [because they produce very large numbers of reproductive propagules (seeds, spores, and so on) and because they have an efficient means of dispersal (normally, wind)]

　　不同植物种类的入侵速度和灭绝速度都有很大不同。先锋物种——那些只出现在定居最早期阶段的物种——倾向于拥有高的入侵速度，因为它们能够产生大量的繁殖体(种子、孢子等)，而且有高效的传播方式(通常是风)。

　　P3: If colonizers produce short-lived reproductive propagules, they must produce very large numbers unless they have an efficient means of dispersal to suitable new habitats. Many plants depend on wind for dispersal and produce abundant quantities of small, relatively short-lived seeds to compensate for the fact that wind is not always a reliable means of reaching the appropriate type of habitat. Alternative strategies have evolved in some plants, such as those that produce fewer but larger seeds that are dispersed to suitable sites by birds or small mammals or those that produce long-lived seeds. 6 Many forest plants seem to exhibit the latter adaptation, 7 and viable 8 seeds of pioneer species can be found in large numbers on some forest floors. For example, as many as 1,125 viable seeds per square meter were found in a 100-year-old Douglas 9 fir/western hemlock forest in coastal British Columbia. Nearly all the seeds that had germinated from this seed bank were from pioneer species. The rapid colonization of such sites after disturbance is undoubtedly in part a reflection of the large seed bank on the forest floor.

　　难词解析：

　　suitable: a.合适的

　　abundant: a.丰富的，充裕的

　　reliable: a.可靠的

　　latter: pron. (已提及的两者中之)後者:

　　注: 可考指代题

　　viable: a.切实可行的

　　germinate: v.(使)萌芽

　　reflection: n.反省，深思，回忆

　　难句解析：

　　Many plants depend on wind for dispersal and produce abundant quantities of small, relatively short-lived seeds to compensate for the fact [that wind is not always a reliable means of reaching the appropriate type of habitat].

　　许多植物依靠风来传播种子;它们产生大量小的、相对短命的种子，以弥补一个事实：风不总是可靠的到达适当栖息地的方式。

　　文章读完了，让我们来检验下你有没有读懂吧~试着往里面填一填~

　　P1 植物定居的简介

　　植物定居的定义:_________________________;植物定居的两个阶段：1)入侵，2)存活

　　P2 植物入侵和灭绝的速度

　　例子：先锋植物入侵速度高的原因：1)_____繁殖体多;2)高效传播方式_______;

　　P3 植物有效定居的对策

　　当抗繁殖体_______时，植物为了有效定定居，有3个对策。

　　Answers：

　　P1：one way in which plants can change the ecology of a site;invasion;survival

　　P2: Pioneer species; wind

　　P3: short-lived

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