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Dazzling Display 色彩缤纷的秋叶

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繁體中文譯本

As sunlight retreats, trees begin to reveal a riot of color  日照渐减，叶子也开始穿上缤纷色彩的外衣

Glorious yellow, burnished orange, radiant red: The appearance of a rainbow of color in an area’s foliage marks the shortening days and reduced daylight of fall. By happy coincidence, one triggers the other. Each year, as the sunlight retreats, the leaves on deciduous trees show their underlying character. Literally.

耀眼黄、光辉橘、灿烂红：某地区的叶子显现出斑斓的色彩，代表秋天的脚步来临了，所以白天愈短，阳光也减弱了。所幸的是，秋天会引发各种自然现象的连锁反应，而每年随着日照开始减弱，落叶性树木的叶子也会开始显现内在潜藏的特色：这可不是比喻，而指的是上述字面上的实际意义喔。

Leaves don’t actually “turn” a different color in autumn; rather they shed their green cloak. The apparent color-changing process happens as chlorophyll, the chemical responsible for green growth, disappears with reduced daylight. Chlorophyll is the necessary component for photosynthesis, the process by which plants use sunlight to turn water and carbon dioxide into glucose.

叶子并不是到了秋天就会「转变成」另一种不同的颜色，而是因为褪下了绿色的外衣，使得内部其他颜色显现出来所致。叶子变色的显而易见的过程，是因为日照减少，导致能引发叶内绿色增长的化学物质叶绿素也渐渐消失，而叶绿素是光合作用的必要成份，植物透过光合作用，利用阳光来把水和二氧化碳转化成葡萄糖。

The reduced hours of daylight, rather than the prevailing temperature, determine when the leaves start to reveal their fall colors. As the nights get longer, the cells at the juncture of the leaf and stem divide rapidly and start to block the nutrients and moisture from the roots reaching the leaves. Once the food supply is cut off, the leaves’ underlying tones of yellow and orange are revealed. In this process, each leaf changes color individually, which accounts for how a tree may have uneven patches of color. What the viewer is observing is actually the absence of green.

至于决定叶子在秋天转换不同色彩的关键，则是日照时间缩短所导致，而不是因为当地盛行的气温。随着夜晚愈来愈长，叶子和茎部连接处的细胞会迅速分离，而阻断根部运送养分和水分到叶部。一旦营养供应遭到切断，叶子里潜藏的黄色和橘色于是显现出来。在这个过程中，由于每片叶子都会各自变色，因此导致整棵树会有色彩不均的情形产生，而观看者所看到的现象，其实是由于绿色消失所引发的结果。

The different colors are determined by the different chemicals inherent in each species. Brown leaves, for example, are the result of tannins in the leaves, and are typical of oaks. The orange of the big-leaf maple represents carotenoids, the same chemical that colors carrots. Xanthophyll, an oxidized derivative of carotene, is responsible for the yellow pigment common to box elder, hickories, ginkgo, black maple, aspen and larch.

至于叶子究竟会变成哪种不同的色彩，则是依照不同树种内含的化学物质所决定。例如，叶子会变成棕色是因为叶内有单宁的关系，这也是橡树常见的现象。大叶槭的叶子会变成橘色，则是因为类胡萝卜素所导致，胡萝卜也是因为含有类胡萝卜素所以会呈现橘色。类胡萝卜素氧化后的衍生物是叶黄素，后者就是白蜡槭、山核桃、银杏、黑槭树、山杨和落叶松属植物的叶子会变成黄色的主因。

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riot [ˋraɪət] n.（色彩等的）丰富 a profusion

glorious [ˋglorɪəs] adj. 壮观的; 壮丽的; 光辉的

burnished [ˋbɝnɪʃt] adj. 铮亮的；光洁的

radiant [ˋredjənt] adj. 光芒四射的；明亮照耀的

foliage [ˋfolɪɪdʒ] n.【书】叶，叶子，簇叶 the leaves of a plant or tree

mark [mɑrk] v. 表示……的特征

deciduous [dɪˋsɪdʒʊəs] adj. 脱落性的；落叶性的 referring to a type of tree that loses its leaves in autumn and grows new ones in the spring

underlying [͵ʌndɚˋlaɪɪŋ] adj. 在下面的；放在下面的; 隐含的; 潜在的

cloak [klok] n. 遮盖物

chlorophyll [ ˈklɔrəfɪl ] n. 叶绿素

photosynthesis [͵fotəˋsɪnθəsɪs] n. 光合作用

juncture [ˋdʒʌŋktʃɚ] n. 接合处，连接点

account for 解释…的原因; 是…的原因

patch [pætʃ] n.（颜色等与周围不同的）斑驳，斑点

tannin [ˋtænɪn] n. 单宁酸

carotenoid [ kə'rɑtnˌɔɪd ] n. 类胡萝卜素

color [ˋkʌlɚ] v. 涂颜色于，着色

carrot [ˋkærət] n. 胡萝卜

Xanthophyll [ˋzænθə͵fɪl] n. 叶黄素

oxidize [ˋɑksə͵daɪz] v. 使氧化 to combine one substance with oxygen to form another substance

carotene [ˋkærə͵tin] n.【生化】胡萝卜素

box elder 白蜡槭（北美洲枫树）

hickory [ˋhɪkərɪ] n. 山胡桃木

aspen [ˋæspən] n. 颤杨; 山杨

larch [lɑrtʃ] n. 落叶松属植物

课文朗读

课文讲解

Only some of the bright reds and deep purples, typical of red maples, sweet gum and flowering dogwoods, are actually manufactured at this time of year by anthocyanin, which also colors plums and cranberries. Scientists have not solved the riddle of what purpose this process serves in old leaves, though it appears to offer some protection from both ultraviolet rays and the frost and enables trees to keep their leaves longer.

唯一不同的是，红花槭、香枫和北美山茱萸花等树叶显现的亮红和深紫色泽，则是因为在秋季时制造的花青素所引发，而后者也是蜜李和小红莓的色彩因子。科学家迄今还没有找出老叶子进行这种过程的原因何在，但答案可能和保护叶子不受紫外线和霜害有关，可以使树保有叶子更久的时间。

Thanks to its combination of climate and a wide variety of deciduous trees, the state of Virginia is one of the best places in the world to observe fall color. The “leaf color flow” along the East Coast of the United States actually follows a wave pattern, according to Kim Coder, professor of silvics at the University of Georgia. The wave starts in mid-September in the mountains of New England, first dominated by yellow, followed by a wave of orange, and finally red, all simultaneously moving downward and southward. When the three colors overlap, the effect is the most dramatic.

由于维吉尼亚州既有特殊天候，又拥有各式各样的落叶树木，使得该州成为全球观察秋叶变色的最佳所在之一。「乔治亚大学」育林学原理教授金．寇德指出，美国东岸「树叶变色的潮流」事实上是宛如波浪般地一波波席卷东岸各地，最早在九月中席卷新英格兰山区，先以黄色为主，然后接着呈现橘色，最后转为红色，而同时这些彩色浪潮会再往下、往南渲染开来，当三种颜色重迭在一起时，则营造出最具戏剧性的效果。

The best conditions for the brightest colors are when the growing season has ample moisture, thereby creating leaf volume, followed by a late summer that’s moderately dry and an autumn with bright, sunny days and cool nights at around 40 degrees. Cloudy weather – which explains Europe’s lack of fall splendor – and warm nights have the opposite effect and tend to bring drab colors. Both high winds and early frosts put an early end to the display of fall color.

想要营造出最亮丽的色彩，最佳条件就是树木的成长季节必须获得充足水分，才能拥有足够的叶量，而且夏季末时，气候还必须适度干燥，至于秋天则必须白天万里无云、阳光充足，而夜晚则应凉爽，温度在华氏四十度左右。相反地，若是天候多云──因此多云的欧洲很难见到秋日彩叶的美景──而且夜晚也太过温暖的话，就会引起相反的效果，导致叶片色泽了无生气。此外，刮大风和霜降提早来临，也可能让秋天彩叶的景致提早划下句点。

－by Prue Salasky

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sweet gum 香枫；香枫之树叶

flowering [ˋflaʊɚrɪŋ] adj. 有花的；开花的

dogwood [ˋdɔg͵wʊd] n. 山茱萸

anthocyanin [͵ænθəˋsaɪənɪn] n.【植】【生化】花青素

riddle [ˋrɪd!] n. 谜，谜语

frost [frɑst] n. 霜

silvics [ 'sɪlvɪks ] n. 造林学, 森林生态学 the science treating of the life of trees in the forest; the scientific study of a tree’s life and its environment

splendor [ˋsplɛndɚ] n. 壮丽；壮观；辉煌

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Vocabulary Focus

coincidence [koˋɪnsɪdəns] n. 巧合；巧事；同时发生 an occasion when two or more similar things happen at the same time, especially in a way that is unlikely and surprising

prevailing [prɪˋvelɪŋ] adj. 盛行的; 占优势的；主要的 existing in a particular place or at a particular time

derivative [dəˋrɪvətɪv] n. 衍生物 a form of something, made or developed from another form

simultaneously [saɪməlˋtenɪəslɪ] adv. 同时地 at exactly the same time

ample [ˋæmp!] adj. 大量的，丰富的，充裕的 more than enough

moderately [ˋmɑdərɪtlɪ] adv. 适度地，有节制地 in a slight or limited manner

drab [dræb] adj. 单调的；无趣的；无生气的 boring, especially in appearance; lacking color and excitement

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