六月份GMAT考試閱讀機(jī)經(jīng) 植物的競(jìng)爭理論.

閱讀是我們復(fù)習(xí)GMAT考試的重點(diǎn)，復(fù)習(xí)GMAT閱讀的時(shí)候考生要認(rèn)真的學(xué)習(xí)基礎(chǔ)知識(shí)。機(jī)經(jīng)是我們現(xiàn)在復(fù)習(xí)閱讀的重要資料，澳際小編分享一些最新的機(jī)經(jīng)，希望大家學(xué)習(xí)到GMAT閱讀技巧：

　　植物的競(jìng)爭理論

　　【v1】將植物的兩種競(jìng)爭理論，一個(gè)就是數(shù)量上彼此競(jìng)爭，一個(gè)是跨代競(jìng)爭(活著的影響幼年的)

　　by 雪霽

　　【v2】很長滿一篇 兩段因?yàn)樯飳W(xué)類名詞不認(rèn)識(shí)看的糊里糊涂

　　說植物容易受兩種方式影響。有個(gè)人的理論就是這植物受周圍競(jìng)爭植物影響， 還受gap 神馬的影響。隨后就解釋了這兩種方式。競(jìng)爭植物就是指周圍生長的植物都對(duì)它有影響。Gap的影響就是老植物影響新植物，在這個(gè)土地上死掉的植物也會(huì)對(duì)現(xiàn)在的植物生長造成影響等等(這里有個(gè)細(xì)節(jié)題就是問植物生長不受哪個(gè)影響?對(duì)比原文可找出沒有的)

　　然后有另個(gè)人做對(duì)比實(shí)驗(yàn)了。這實(shí)驗(yàn)針對(duì)一種植物，選擇這種植物是因?yàn)榧仍诖禾焐L也在秋天生長，所以方便研究這兩種關(guān)于競(jìng)爭理論及跨代理論的影響。然后發(fā)現(xiàn)春天的木有變化(很多細(xì)節(jié),也就是說不會(huì)受跨代影響?) 發(fā)現(xiàn)秋天的有變化……… (受跨代影響?)

　　(構(gòu)筑木有搞懂邏輯鏈怎么個(gè)回事)

　　By Fannyyy

　　考古：

　　樹木的密度以及生態(tài)學(xué)理論(長)

　　V1：by lxfbear

　　講生態(tài)學(xué)GAP XX THEORY的,講樹分布的密度和它周圍樹木,和它們遺傳關(guān)系啥的.

　　V2：by airphone

　　先介紹了the neighborhood-competition theory，就是說植物是通過同代植物的相互作用影響競(jìng)爭，即植物的生長和繁殖是由周圍的競(jìng)爭者決定的。若競(jìng)爭者離這些物種在一定的距離之外，那么久不會(huì)產(chǎn)生影響了。然后介紹the gap-colonization theory，通過隔代植物的相互作用影響競(jìng)爭，即該理論認(rèn)為，上一代的植物抑制本代植物的生長和繁殖。

　　接下來用兩組實(shí)驗(yàn)來驗(yàn)證這兩種理論。

　　實(shí)驗(yàn)一：

　　第一組：spring時(shí)期播種a patchy distribution of bluegrass + a randomdistribution of 四分之一bluegrass數(shù)量的groundsel

　　第二組：spring時(shí)期播種a random distribution of bluegrass+ a random distributionof 四分之一bluegrass數(shù)量的groundsel

　　實(shí)驗(yàn)一結(jié)果：fall時(shí)期發(fā)現(xiàn)第一組的groundsel數(shù)量超出第二組4倍多.實(shí)驗(yàn)一結(jié)果可以證明同代植物空間布局對(duì)植物生長影響非常大，However, 這些結(jié)果不能證明理論1，因?yàn)檫@兩種G產(chǎn)出的種子都是一樣的，也就是說不影響繁殖。實(shí)驗(yàn)一還發(fā)現(xiàn)，在PATCHY實(shí)驗(yàn)組中，bluegrass low density的地方，G長得多。確實(shí)，證明了空間布局影響了生長。

　　實(shí)驗(yàn)二

　　在實(shí)驗(yàn)一中的兩塊試驗(yàn)種植地中，分別取一半remove掉bluegrass的上一代的植物，在另一半中，保持上一代植物完好無損;其他條件與實(shí)驗(yàn)一相同(注意，是四塊不同土地進(jìn)行對(duì)比了。)

　　實(shí)驗(yàn)結(jié)果：在上一代完好的情況下，G在patchy的土地中長得更好。在移除上一代的情況下，G在patchy 和random的土地中長的一樣。說明上一代的植物確實(shí)影響了當(dāng)代的植物。該實(shí)驗(yàn)證明，競(jìng)爭是隔代的，而不是在當(dāng)代的。即驗(yàn)證了理論二—隔代競(jìng)爭理論。

　　考古

　　第一段：關(guān)于植物seedling的分布，有兩種理論(neighbour theory and gap theory)：

　　理論1. 影響植物分布的原因是同種類植物的種植的density。Density緊密的seedling 比較少，density比較稀疏的則seedling比較多

　　理論2. 影響植物分布的原因是他種植物的存在(尤其達(dá)到adult成熟期的他種植物)，到達(dá)adult期的非同種植物會(huì)影響下一種在此塊土地上生長的植物。(影響因素：1. 非同種adult植物遺留下來的殘?jiān)?2. 忘了)

　　第二段：【整個(gè)段落是一個(gè)research，關(guān)于上述兩種理論。此處木木的第一題全段高亮，考察該段作用】

　　有A和B兩種植物(B植物在文中似乎是叫bluegrass，A植物全稱記不太清晰了)：

　　A和B都是：spring+fall兩季的

　　Spring：B植物：一部分稀疏地seedling，一部分密集地seedling;

　　結(jié)果：稀疏seedling的長得多，密集seedling的長得少【木木infer：證明了理論一】

　　A植物：全部稀疏地seedling(按照wild的density，是B植seedling的1/4密度)

　　Fall：將A植物種植在原本B植物種植處：

　　結(jié)果：原本B植物seedling稀疏處(即原本的B植物長得好)，A植物seedling相對(duì)不好;

　　原本B植物seedling密集處(即原本的B植物生得不好)，A植物的seedling相對(duì)好

　　【木木infer：證明理論二】

　　PS：(另一狗主補(bǔ)充第二段)好像說bluegrass密度高的地方G就低，因?yàn)閎luegrass殘留的根莖會(huì)阻止G植物的根發(fā)育，但不會(huì)影響bluegrass的根發(fā)育。

　　Q1：植物seedling受到以下因素影響，except 選植物發(fā)芽的情況

　　Q2.：第二段的試驗(yàn)的primate目的是選為gap假說提供data

　　Q3：以下哪個(gè)可以weaken neighborhood theory的。

　　Q4：有道題說以下什么weaken the gap theory我選的是G植物的密度不受bluegrass密度的影響。

　　Q5：第二段的主旨，我選的是講解bluegrass 對(duì)G植物的影響。待選項(xiàng)有 G對(duì)bluegrass的影響;削弱某個(gè)理論等等

　　Q6：什么不會(huì)影響植物的繁殖密度，我選的是植物種子的發(fā)芽情況 (可能不準(zhǔn))

　　Q7：(V42)有一道主旨，我選的是evaluate two theories and the evidence差不多這個(gè)

　　參考文獻(xiàn)(非原文)

　　In the groundsel-bluegrass system, competition portrays a race in which small differences in emergence produce large differences in performance, and seeds respond vigorously to clues that indicate the presence of competitors.

　　Apparently, the threat of competition shapes the activity of these seeds. That raises broader questions: To what extent does competition influence the population dynamics of competitors, and to what extent does community context influence competitive interactions? Although biologists commonly assume that competition affects the dynamics of plant communities, we are just beginning to explore the interplay between individual performance, which responds to competition, and population and community-level factors. Such research provides an important arena for testing our understanding of the forces that structure plant communities.

　　At this interface between individuals and communities of plants, spatial patterning receives a disproportionate share of attention. Two distinct theories have been developed that predict that spatial patterning can exert a strong influence on competitive interactions. Since plant populations exhibit very patchy arrangements, as opposed to random distributions, the question arises as to whether patterning drives the dynamics of plant populations in nature.

　　Stephen Pacala of Princeton University and John Silander of the University of Connecticut champion the neighborhood-competition theory. That theory assumes that plant growth and reproduction depend on the density of nearby competitors and that competitors beyond a designated distance exert no impact on a particular plant. Combining that assumption with an elaborate mathematical theory suggests that patchiness in a distribution of competitors can profoundly alter competition at the population level. Intuitively, this theory can be understood by recognizing that patchiness leads to considerable variation in the amount of competition experienced by any individual plant. Some plants will experience lots of competition and experience little reproduction; other plants will be virtually free from competition and contribute a disproportionately large share to the next generation. In this way, the neighborhood-competition theory suggests that the spatial pattern of plants influences competition through interactions between contemporaneous plants.

　　An alternative theory for patchiness, gap colonization, considers the competitive impact of one generation on another. Traditionally, this theory has been applied to the dynamics of forests, where the germination and growth of seedlings depends on gaps lt after trees fall. Nevertheless, it might be equally relevant to the dynamics of grassland plants. In nearly all cases, established vegetation can overpower seedlings. In fact, seedling emergence and survival can be totally inhibited by the presence of adult plants, or even by the litter lt from previous generations. This type of inhibition can arise from several factors: chemicals, shading or structural interference produced by the established plants. In some cases, these factors may restrict seedling survival to areas that lack established vegetation. Moreover, the gaps in a patchy spatial pattern promote the persistence of competitively inferior plants. Gap-colonization theory, then, suggests that an area’s spatial pattern will influence competitive interactions because previous generations affect the survival of present seedlings.

　　Competition between common groundsel and annual bluegrass also depends on spatial patterns. Both of these species produce two generations each year-one in the spring and another in the fall. This rather unusual life cycle proves tremendously convenient for testing the neighborhood-competition and gap-colonization theories. In each fall generation, newly emerging seedlings compete with each other, which provides an opportunity for neighborhood competition, and they also interact with remnants from the spring generation, which could lead to gap colonization.

　　上述就是小編分享的GMAT考試閱讀機(jī)經(jīng)，復(fù)習(xí)GMAT閱讀的時(shí)候考生要積極利用好復(fù)習(xí)資料。希望考生們多掌握一些GMAT閱讀技巧，祝大家閱讀考試復(fù)習(xí)順利。

澳際六步曲服務(wù)體系由六大步驟和36項(xiàng)子模塊組成，核心內(nèi)容包括留學(xué)理性規(guī)劃和背景提升、考試個(gè)性化輔導(dǎo)、文書創(chuàng)作和學(xué)校申請(qǐng)、套磁和面試、簽證輔導(dǎo)及后期服務(wù)、海內(nèi)外求職。澳際六步曲體系貫穿澳際所有服務(wù)項(xiàng)目：美國名校本科申請(qǐng)，名校碩士申請(qǐng)，博士獎(jiǎng)學(xué)金申請(qǐng)，TOP 20 MBA精英申請(qǐng)，英國/加拿大TOP 10申請(qǐng)等。澳際六步曲服務(wù)體系適合人群：適合現(xiàn)在高一、高二、大一、大二和大三的學(xué)生，希望自己未雨綢繆，從根本上提升申請(qǐng)競(jìng)爭力，從而于畢業(yè)之際成功步入世界名校。詳細(xì)了解澳際六步曲：goplaceswithdan.com