托福 新托福 40 - Latitude and Biodiversity
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1.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage?
Incorrect choices change the meaning in important ways or leave out essential information.
  • A.Some biogeographers believe that the tropics have larger surface areas than they actually do because of the distortions produced by projections of Earth’s curved surface
  • B.High levels of diversity in the tropics are sometimes attributed to the fact that the tropics have more surface area of land than the higher latitudes do, though distortions in commonly used projections may seem to suggest otherwise.
  • C.Because biogeographers disagree on whether or not the tropics are correctly represented in projections of Earth s surface, it is difficult to determine the relationship their surface area has to their diversity
  • D.Most biogeographers agree that the tropics contain a larger surface area of land than higher latitudes do,but they disagree on whether or not the tropics’ level of diversity is a reflection of that larger surface area.
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    阅读原文 中文译文

    When we look at the way in which biodiversity (biological diversity) is distributed over the land surface of the planet, we find that it is far from even. The tropics contain many more species overall than an equivalent area at the higher latitudes. This seems to be true for many different groups of animals and plants.

    Why is it that higher latitudes have lower diversities than the tropics? Perhaps it is simply a matter of land area. The tropics contain a larger surface area of land than higher latitudes—a fact that is not always evident when we examine commonly used projections of Earth’s curved surface, since this tends to exaggerate the areas of land in the higher latitudes—and some biogeographers regard the differences in diversity as a reflection of this effect. But an analysis of the data by biologist Klaus Rohde does not support this explanation. Although area may contribute to biodiversity, it is certainly not the whole story; otherwise, large landmasses would always be richer in species.

    Productivity seems to be involved instead, though perhaps its influence is indirect. Where conditions are most suitable for plant growth—that is, where temperatures are relatively high and uniform and where there is an ample supply of water—one usually finds large masses of vegetation. This leads to a complex structure in the layers of plant material. In a tropical rain forest, for example, a very large quantity of plant material builds up above the surface of the ground .There is also a large mass of material, developed below ground as root tissues, but this is less apparent. Careful analysis of the above ground material reveals that it is arranged in a series of layers, the precise number of layers varying with age and the nature of the forest. The arrangement of the biological mass ("biomass") of the vegetation into layered forms is termed its “structure” (as opposed to its “composition,” which refers to the species of organisms forming the community). Structure is essentially the architecture of vegetation, and as in the case of tropical forests, it can be extremely complicated. In a mature floodplain tropical forest in the Amazon River basin, the canopy (the uppermost layers of a forest, formed by the crowns of trees) takes on a stratified structure. There are three clear peaks in leaf cover at heights of approximately 3, 6, and 30 meters above the ground; and the very highest layer, at 50 meters, corresponds to the very tall trees that stand free of the main canopy and form an open layer of their own. So, such a forest contains essentially four layers of canopy. Forests in temperate lands often have just two canopy layers, so they have much less complex architecture.

    Structure has a strong influence on the animal life inhabiting a site. It forms the spatial environment within which an animal feeds, moves around shelters, lives, and breeds. It even affects the climate on a very local level (the "microclimate") by influencing light intensity, humidity, and both the range and extremes of temperature. An area of grassland vegetation with very simple structure, for example, has a very different microclimate at the ground level from that experienced in the upper canopy. Wind speeds are lower, temperatures are lower during the day (but warmer at night), and the relative humidity is much greater near the ground. The complexity of the microclimate is closely related to the complexity of structure in vegetation, and generally speaking, the more complex the structure of vegetation, the more species of animal are able to make a living there. The high plant biomass of the tropics leads to a greater spatial complexity in the environment, and this leads to a higher potential for diversity in the living things that can occupy a region. The climates of the higher latitudes are generally less favorable for the accumulation of large quantities of biomass; hence, the structure of vegetation is simpler and the animal diversity is consequently lower.

    当我们在研究生物多样性在地球表面的分布方式时,我们发现这种分布是很不均匀的。总的来说,热带地区比高纬度地区同等面积要包含更多的物种。这对许多不同的动物和植物群体来说似乎如此。 为什么高纬度地区要比热带物种数量少?这也许仅仅是与土地面积有关。热带地区比高纬度地区土地面积更大——当我们在审视通常所用的地球曲面投影时,这一事实并不总是显而易见的,因为这往往夸大了高纬度的土地面积——一些生物地理学家认为物种多样性的差异反映了这一点。但生物学家克劳斯罗德的数据分析并不支持这样的解释。虽然面积可能影响生物多样性,这当然不是全部的影响因素;否则,面积大的陆块总会有更丰富的物种。 生产力似乎也有作用,但也许它的作用是间接的。那些条件最适合植物生长的地方,即温度相对比较高,温差小,有充足水源的地方,通常会有大量的植被。这就导致了一个复杂的植物体层级结构。例如,在一个热带雨林中,有大量的植物体生长在地面之上,也有大量的不显眼的根系组织位于地下。仔细分析地面以上的部分,发现它分成很了多层,层的具体数目随着森林的年龄和性质而变化。植被的生物量的分层形式被称为“结构”(区别于“组成”,指的是形成群落的各种物种)。结构基本上是植被的架构。对于热带森林来说,结构是非常复杂的。在一个成熟的亚马逊冲积平原的热带森林中,树冠(森林最上面的层,由树木的冠组成)就是一个分层结构。枯枝落叶层有三个明显的峰值,分别在距离地面3米、6米和30米的高度;在最高的那一层,约在距离地面50米高的地方,非常高大的树木并不属于主冠,而是形成自己的一层。所以,这样的森林本质上包含了四层树冠。温带的森林通常只有2个冠层,所以它们的结构没那么复杂。 结构对栖息在一个地方的动物的生活有很大的影响。它构成了动物觅食、在周围活动、生活和繁殖的空间环境。它甚至会通过影响光照强度、湿度以及最高温度和最低温度来影响当地气候(“小气候”)。例如,结构简单的草地,它在地面的微气候就和上层的树冠层不同。接近地面的地方,风速较低,白天气温也低(但夜间比较高),相对湿度更大。小气候的复杂性与植被结构的复杂程度密切相关,一般而言,植被的结构越复杂,在此生活的动物种类就越多。热带地区庞大的生物量导致了环境的更大的空间复杂度,也就使得住在这个区域的生物的多样性可能更高。高纬度地区的气候条件一般不利于大量生物的集聚,因此,植被结构更简单些,动物的多样性也相应较低。

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    • wx_6697
      觉得B C 意思一样,不知道选哪个
    • wx_5576
    • wx_5576
    • wx_6697
      TPO30 passage 2 Q5我选的 D,不明白为啥不对?
    • wx_6697
      鑫哥,TPO6passage3Q5 答案是给错了吗?好多人都选A
    • wx_6697
    • wx_6697
    • 芊儿
      为什么这道题不选c??a中的variety不是应该对应文中的differentiating 吗??求解!
    • wx_1000
    • 王金阁
    • 芊儿
      这道题的D选项不是和文中的better able to reproduce in open settings相对应么??
    • 风荨火
    • 以沫
      请问这个D 在哪里提现?为什么D错?
    • 芊儿
      第六题 的C选择为什么不对,感觉A是明显驳斥啊...
    • wx_6697
    • wx_6697
      这题选的A,根据是Joly’s calculations clearly supported those geologists who insisted on an age for Earth far in excess of a few million years.想问鑫哥为啥不选A
    • wx_6697
      这题我选的是C依据是into a new habitat outside of its natural range, it may adapt to the new environment and leave its enemies behind.C为啥错了呢?鑫哥
    • wx_8861
      F选项的weather-related destruction在哪里体现了呢?原文最后一段的开头Among the costs里的costs是不是打错了?应该是coast?
    • wx_6697
      求问这道题B为啥不选,原文依据:viable seeds of pioneer species can be found in large numbers on some forest floors.
    • 与托福的斗争史
      与托福的斗争史 去解答 去解答
    • 小雨淅沥哗啦的下
      小雨淅沥哗啦的下 去解答 去解答
    • 小雨淅沥哗啦的下
      小雨淅沥哗啦的下 去解答 去解答
    • 李浩然
    • wx_100
    • wx xxxxx
      请问鑫哥,这段开头有写As one pesticide replaces another为什么不是对应a new pesticide is developed?
    • wx_7695
      鑫哥,从哪里看出来这个masks 不是use呀,原文说了wear呀
    • haiyuqiao
      @鑫哥,这题the damage will continue 不应该对应前面的 the target species evolves resistance to it,然后As one pesticide replaces another,不应该是结束了time cycle 吗
    • wx_2065
    • wx_7695
      鑫哥,B选项 cannot extended to earlier geological periods. 原文说的意思是后来的进化无法估计吧
    • wx_2163
    • wx_7780
    • 100
      看到第一句话,以为是中心句就选了A... 为什么不能选A呢
    • 100
    • gu33
      请问下 这里选D的原因是 因为 evolutionary approach 对应着 原文的 Rates of evolution 嘛? 这里我选了C。。不是很懂 插入句和 D的关系 求解答
    • 我是啦啦啦
      我是啦啦啦 去解答 去解答
    • haiyuqiao
    • wx_7060
      为什么选a 呢。我觉得a是细节。F哪错了?
    • wx_1105
    • wx_8122
    • wx_1655
    • chaulaw
    • chaulaw
    • wx_6697
      鑫哥,这道题答案是不是错了,好多人选D 我也选的D求解答
    • wx_6697
    • wx_6697
    • wx_6697
    • wx_6697
    • wx_4185
      it is difficult to say how far they were intended to be portraits rather than generalized images 这句话怎么理解呢
    • 此楠楠
    • 此楠楠
      求鑫哥讲解下A选项。。。 Even though in error, Joly’s calculations clearly supported those geologists who insisted on an age for Earth far in excess of a few million years.