Plant Colonization 植物“殖民主義” P1: Colonization is one way in which plants can change the ecology of a site. Colonization is a process with two components: invasion and survival. The rate at which a site is colonized by plants depends on both the rate at which individual organisms (seeds, spores, immature or mature individuals) arrive at the site and their success at becoming established and surviving. Success in colonization depends to a great extent on there being a site available for colonization – a safe site where disturbance by fire or by cutting down of trees has either removed competing species or reduced levels of competition and other negative interactions to a level at which the invading species can become established. For a given rate of invasion, colonization of a moist, fertile site is likely to be much more rapid than that of a dry, infertile site because of poor survival on the latter. A fertile, plowed field is rapidly invaded by a large variety of weeds, whereas a neighboring construction site from which the soil has been compacted or removed to expose a coarse, infertile parent material may remain virtually free of vegetation for many months or even years despite receiving the same input of seeds as the plowed field. 難詞解析： site: n.場所;位置; vt. 設(shè)置;為…選址 component: n.成分;組件;adj.組成的 survive：v.幸存;幸免于;比...活得長 mature：v.成熟，使…成熟; adj. 成熟的;充分考慮的;到期的;成年人的 established：v. 確立的;已制定的 available: adj.可得的;空閑的 removed：adj. 被移開的，遠(yuǎn)離的 construction: n. 構(gòu)造，建筑 virtually：adv. 幾乎 despite: prep. 盡管 難句解析： Success (in colonization)depends to a great extent on there being a site (available for colonization) – a safe site [where disturbance by fire or by cutting down of trees has either removed competing species or reduced levels of competition and other negative interactions] to a level [at which the invading species can become established.] 定居的成功很大程度上取決于有一個合適的定居地點(diǎn)——一個安全的地點(diǎn)中，因為火或伐樹造成的干擾移除了競爭物種，或者將競爭和其他消極作用降低到了入侵物種能夠定居的水平。 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) 難詞解析： extinct: v.滅絕 efficient：adj.有效率的 means：n.手段，方法;財富 disperse： v. 散開 難句解析： 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)] 不同植物種類的入侵速度和滅絕速度都有很大不同。先鋒物種——那些只出現(xiàn)在定居最早期階段的物種——傾向于擁有高的入侵速度，因為它們能夠產(chǎn)生大量的繁殖體(種子、孢子等)，而且有高效的傳播方式(通常是風(fēng))。 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. 難詞解析： suitable: a.合適的 abundant: a.豐富的，充裕的 reliable: a.可靠的 latter: pron. (已提及的兩者中之)後者: 注: 可考指代題 viable: a.切實可行的 germinate: v.(使)萌芽 reflection: n.反省，深思，回憶 難句解析： 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]. 許多植物依靠風(fēng)來傳播種子;它們產(chǎn)生大量小的、相對*的種子，以彌補(bǔ)一個事實：風(fēng)不總是可靠的到達(dá)適當(dāng)棲息地的方式。 文章讀完了，讓我們來檢驗下你有沒有讀懂吧~試著往里面填一填~ P1 植物定居的簡介 植物定居的定義:_________________________;植物定居的兩個階段：1)入侵，2)存活 P2 植物入侵和滅絕的速度 例子：先鋒植物入侵速度高的原因：1)_____繁殖體多;2)高效傳播方式_______; P3 植物有效定居的對策 當(dāng)抗繁殖體_______時，植物為了有效定定居，有3個對策。 Answers： P1：one way in which plants can change the ecology of a site;invasion;survival P2: Pioneer species; wind P3: short-lived