The Food Chains
食物链 I-17 / 017

The whole ecology of a given location on the earth can become unbalanced with the disappearance of just a single creature. This is because of a system called the food chain. The food chain is a concept that was developed by a scientist named Charles Elton. In 1927, he laid out the process by which plants get their energy from the sunlight, plant-eating animals get energy from eating plants, and meat-eating animals get their energy from other animals. Seen in black and white, this looks very much like a chain, with its links all together.

Let's look at the food chain more closely. The food chain has four basic parts.

● The first part is the sun. The sun provides the energy for everything on the earth.

● The second part is known as producers. Producers are all green plants. They make their own food, and every organism is in part dependent on plants for the oxygen and/or food they need.

● Consumers are the third part of the food chain. Consumers are, very simply, every organism that eats something else, whether it is a carnivore (eats meat), an herbivore (eats plants), an omnivore (eats plants and animals), a parasite (relies on another living thing to provide food), or a scavenger (usually feeds on dead organisms).

● The fourth part of the food chain is decomposers. These organisms, such as fungi and bacteria, break down dead matter into important gases that are released back into the ground, air, or water. These“recycled” nutrients are then used by the producers in their growth process.

Look at the simplified food chain on the right. The sunlight helps the grass to grow, the rabbit eats the grass, and the fox eats the rabbit. Because the fox does not have a predator, it is the “top” of this food chain.

If something happens to the grass—perhaps a drought occurs—and the rabbits have less food, many may die. Without as many rabbits to eat, some of the foxes in the area may also die or leave the location. While this is a very simple food chain (because rabbits do eat things other than grass), you can see that the disappearance of one element in the chain can have a lasting effect.

Words and Phrases

ecology [ɪˈkɒlədʒɪ] 名 生态学；生态系统

location [ləʊˈkeɪʃn] 名 位置，场所

food chain 食物链

concept [ˈkɒnsept] 名 概念，观念，想法

lay out 展示；设计

energy [ˈenədʒɪ] 名 能量；能源

plant-eating 形 以植物为食的

meat-eating 形 以肉为食的

in black and white 很清楚；以书面形式

producer [prəˈdju:sə(r)] 名 生产者，制造者

organism [ˈɔ:ɡənɪzəm] 名 有机物；有机体；生物体

oxygen [ˈɒksɪdʒən] 名 氧气

consumer [kənˈsju:mə(r)] 名 消费者；取食者

carnivore [ˈkɑ:nɪvɔ:(r)] 名 食肉动物

herbivore [ˈɜ:rbɪvɔ:(r)] 名 食草动物

omnivore [ˈɒmnɪvɔ:(r)] 名 杂食动物

parasite [ˈpærəsaɪt] 名 寄生物

scavenger [ˈskævɪndʒə(r)] 名 食腐动物

decomposer [di:kənˈpəʊzə] 名 分解者

fungi [ˈfʌŋɡi:] 名 真菌（fungus的复数形式）

bacteria [bækˈtɪərɪə] 名 细菌（bacterium的复数形式）

nutrient [ˈnju:trɪənt] 名 营养物质；形 营养的

predator [ˈpredətə(r)] 名 食肉动物；掠夺者，猎食者

lasting [ˈlɑ:stɪŋ] 形 持久的，恒久的

Practice

Directions: Use the reading above to help define the following terms.

1. Consumers____________________________________________________________________________________

2. Producers____________________________________________________________________________________

3. Food chain____________________________________________________________________________________

译文

食物链

地球上一个特定地方的整个生态系统会随着一种生物的消失而失衡。这源于一个称为食物链的系统。食物链的概念是由一位名叫查尔斯·埃尔顿的科学家提出来的。1927年，他列出了一个过程，在这个过程中，植物靠吸收阳光获取能量，食草动物通过吃植物获得能量，而食肉动物则靠吃其他的动物获取能量。很明显，这一过程非常像一个链条，把各类生物联系在了一起。

让我们更仔细地来看看食物链，它由四个基本部分构成：

· 第一部分是阳光。阳光给地球上所有的生物提供能量。

· 第二部分是生产者。生产者都是绿色植物，它们是自养生物。所有的有机生物或多或少都依赖植物为它们提供所需的氧气和/或养料。

· 第三部分是消费者。简单来说，消费者指的是靠吃其他生物为生的有机生物。消费者可以是食肉动物（吃肉）、食草动物（吃植物）、杂食动物（吃植物和动物）、寄生生物（靠其他活着的生物提供食物）或食腐动物（通常以死亡的有机生物为食）。

· 第四部分是分解者。分解者是有机生物，比如真菌及细菌，它们会把死亡生物分解成重要的气体，这些气体回归到地面、空气或水中，然后这些“回收的”营养物质被生产者用于生长进程。

看右侧的食物链简化图。阳光帮助草生长，兔子吃草，狐狸吃兔子。因为没有猎食者捕食狐狸，所以它是这个食物链的“最顶端”。

假如草发生了变化，可能是遭遇干旱，那么兔子的食物就会减少，这可能导致许多兔子死亡。兔子不够吃，那么这个地区的部分狐狸也会死亡，或是选择离开。虽然这只是个非常简化的食物链（因为兔子除了吃草外，还会吃其他东西），但通过这张图，你就能看出食物链中某组成部分的消失，将带来持续性的影响。

练习

说明：通过阅读以上文章来定义下列名词。

1．消费者____________________________________________

2．生产者____________________________________________

3．食物链____________________________________________

答案