章节大纲

  • 常规

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  • 生态系统中的物质流动

    Assorted citrus fruits, including oranges, lemons, and limes, emphasizing vitamin C's importance.

     

    What happens when you don't get enough of a nutrient?
    ::当你得不到足够的养分时会怎样?

    Millions of sailors in the 15th through 18th centuries died mysteriously. They developed a disease called scurvy. The scurvy, it turns out, was due to the lack of vitamin C in their diets. It wasn't until 1932 that the link between scurvy and vitamin C was made. Without the right  nutrients  in the right amounts, you can't live. Other animals and plants also need the right nutrients to live.
    ::15世纪到18世纪,数百万水手神秘地死去了。他们发展出了一种叫做阴道的疾病。结果发现,这种阴道的腐烂是由于他们的饮食缺乏维生素C。直到1932年,才将腐烂和维生素C联系起来。没有正确数量的营养素,你就无法生存。其他动物和植物也需要正确的营养素才能生存。

    How Matter Moves Through Ecosystems
    ::物质如何在生态系统中移动

    Living things need nonliving matter as well as  energy . What do you think matter is used for? It's used to build bodies. It's also needed to carry out the processes of life. Any nonliving matter that living things need is called a  nutrient . Carbon and nitrogen are examples of nutrients. Unlike energy, matter is recycled in  ecosystems . In the figure below, you can see how ( Figure   ).
    ::生活物质需要非生物物质和能量。 你认为物质是用来做什么的? 它用来建造身体。 也需要用来进行生命过程。 任何非生物物质需要的东西都被称为养分。 碳和氮是养分的例子。 与能源不同, 物质在生态系统中被回收。 在下图中, 您可以看到如何( 图 ) 。

    • Decomposers  release nutrients when they break down dead organisms.
      ::分解器在分解死亡生物时释放养分
    • The nutrients are taken up by plants through their roots.
      ::植物通过根部吸收养分
    • The nutrients pass to primary consumers when they eat the plants.
      ::养分在主要消费者吃植物时传递给他们。
    • The nutrients pass to higher level consumers when they eat lower level consumers.
      ::养分在消费较低水平的消费者时传递给较高层次的消费者。
    • When living things die, the cycle repeats.
      ::当生命死去时 循环会重复

    The cycle of matter in ecosystems, showing interactions among decomposers, producers, and consumers.

     

    This diagram shows two cycles. One is the cycle of energy, the other is the cycle of matter. Compare the two cycles. Do you see how the Sun keeps adding energy? That’s because energy is lost at each step of the cycle. Matter doesn’t have to be added. Can you explain why?
    ::这个图表显示了两个周期。 一个是能源循环, 另一个是物质循环。 比较两个周期。 你是否看到太阳是如何增加能源的? 这是因为能源在周期的每一个阶段都丧失了。 物质不需要添加。 你能解释为什么吗?

    Summary
    ::摘要

    • Nutrients are crucial to the growth of organisms.
      ::养分对生物的生长至关重要。
    • Decomposers break down dead organisms into nutrients and gases so that they can be used by other organisms.
      ::分解器将死亡生物分解成养分和气体,以便供其他生物使用。
    • Nutrients can enter or exit an ecosystem at any point and can cycle around the planet.
      ::养分可以在任何时间进入或离开生态系统,并环绕地球循环。

    Review
    ::回顾

    1. How does the flow of matter differ from the flow of energy through an ecosystem?
      ::物质流动与通过生态系统的能源流动有何不同?
    1. How do nutrients move through an ecosystem?
      ::养分如何在生态系统中流动?
    1. What would happen to life on Earth if there were no decomposers? Why?
      ::如果没有分解者,地球上的生命会怎样?为什么?

     

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. What form does carbon take in the atmosphere?
      ::碳在大气中采取什么形式?
    1. What do producers do with carbon?
      ::生产者对碳做什么?
    1. What happens to the carbon in stored in leaves?
      ::储存在叶子中的碳会怎么样?
    1. Once the carbon is on the ground, where can it be stored?
      ::一旦碳在地面上,它可以储存在哪里?
    1. Where is the carbon in a temperate, deciduous forest?
      ::温和、衰落的森林中的碳在哪里?
    1. Where is the carbon in a rainforest?
      ::雨林中的碳在哪里?
    1. Where is the carbon in the frigid Arctic? How much is in biomass?
      ::冰冷的北极的碳在哪里?生物量中有多少?
    1. How does methane form in a peat bog?
      ::沼气如何形成在泥炭沼泽?