Section outline

  • General

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  • 继承继承继承继承

    What you will learn
    ::你会学到什么

    • What is ecological succession
      ::什么是生态继承
    • Types of ecological succession
      ::生态继承类型
    • How do climax communities form
      ::如何形成高潮社区

    A small, hardy plant growing on cracked lava rock, illustrating plant succession.

    Can a plant really grow in hardened lava?
    ::植物真的能在硬岩中生长吗?

    It can if it is very hardy and tenacious. And that is how succession starts. It begins with a plant that must be able to grow on new land with minimal soil or nutrients .
    ::如果它非常坚硬和坚固,它就能够。这就是继承的开端。它始于一种植物,它必须能够在新的土地上生长,土壤或养分微乎其微。

    Ecological Succession
    ::生态继承

    Communities are not usually static. The numbers and types of that live in them generally change over time. This is called ecological succession . Important cases of succession are primary and secondary succession . Both these types of succession involve a series of stages that lead to the formation of stable communities.
    ::社区通常不是静止的,生活在社区中的人数和类型通常随时间而变化,这称为生态继承,重要的继承情况是初级和二级继承,这两种继承都涉及一系列阶段,导致形成稳定的社区。

     

     

    Primary Succession
    ::初级继承

    Primary succession occurs in an area that has never before been colonized. Generally, the area is nothing but bare rock. This type of environment may come about when
    ::原始继承发生在一个以前从未被殖民过的地区,通常该地区只是赤裸的岩石。

    • lava flows from a volcano and hardens into rock.
      ::熔岩从火山流出 硬化成岩石
    • a glacier retreats and leaves behind bare rock.
      ::冰川退缩 留下赤裸的岩石
    • a landslide uncovers an area of bare rock.
      ::山崩揭开一片裸露的岩石

    The first species to colonize a disturbed area such as this are called pioneer species (see the Figure ). They change the environment and pave the way for other species to come into the area. Pioneer species are likely to include , lichens, and mosses that can live on bare rock. Along with wind and , they help weather the rock and form soil. Once soil begins to form, plants can move in. At first, the plants include grasses and other species that can grow in thin, poor soil. As more plants grow and die, organic matter is added to the soil. This improves the soil and helps it hold water. The improved soil allows shrubs and trees to move into the area.
    ::最早将这种动乱地区殖民化的物种称为先驱物种(见图 ) 。 它们改变了环境,并为其他物种进入该地区铺平了道路。 先锋物种可能包括能够生活在赤裸岩石上的土壤、 地衣和苔。 它们与风一起帮助气候, 形成岩石和土壤。 一旦土壤形成, 植物就可以移动。 首先, 植物包括草和其他可以生长在薄薄土壤中的物种。 随着更多的植物生长和死亡, 有机物质会添加到土壤中。 这可以改善土壤, 帮助土壤保持水。 改良的土壤允许灌木和树木进入该地区 。

    Close-up of moss and lichen growing on bare rock, illustrating pioneer species in primary succession.
    Pioneer species such as mosses and lichens can live on bare rock.

    Secondary Succession
    ::中继继承

    Secondary succession occurs in a formerly inhabited area that was disturbed. The disturbance could be a fire, flood, or human action such as farming. This type of succession is faster because the soil is already in place. In this case, the pioneer species are plants such as grasses, birch trees, and fireweed. Organic matter from the pioneer species improves the soil. This lets other plants move into the area.
    ::二次继承发生在一个曾有人居住的、被扰动的地区,扰动可能是火灾、洪水或人类行为,如耕种,这种类型的继承速度更快,因为土壤已经就位;在这种情况下,先驱物种是草、树枝和火草等植物;先驱物种的有机物质改善土壤。这让其他植物进入该地区。

    A forest recovering from a fire, showing new plant life among charred trees.
    Secondary Succession. A year after a forest fire, new plant life has sprouted among the charred trees.

    Climax Communities
    ::高潮社区

    Many early ecologists thought that a community always goes through the same series of stages during succession. They also assumed that succession may include the formation of intermediate communities but it always ends with a final stable stage. They called this stage the climax community . Today, most ecologists no longer hold these views. They believe that continued change is normal in most . They think that most communities are disturbed too often to become climax communities.
    ::许多早期的生态学家认为,一个社区在继承过程中总是经历同样的一系列阶段,他们还假设继承可能包括中间社区的形成,但最后总是以最终的稳定阶段结束。他们称这一阶段为高潮社区。如今,大多数生态学家不再持有这些观点。他们认为,在大多数情况下,持续的变化是正常的。他们认为,大多数社区经常受到干扰,无法成为高潮社区。

    The stages of primary succession from bare rock to the formation of the climax community
    ::从裸露的岩石到形成顶峰社区的初级继承阶段

    The stages of secondary succession after a forest fire
    ::森林火灾后第二继承阶段

     

     

     

    Summary
    ::摘要

    • Ecological succession is the process in which a community changes through time.
      ::生态继承是一个社区随着时间的推移而变化的过程。
    • Primary succession occurs in an area that has never before been colonized.
      ::初级继承发生在一个从未被殖民的地区。
    • Secondary succession occurs in a formerly inhabited area that was disturbed.
      ::二级继承发生在被扰动的前有人居住的地区。

    Review
    ::回顾

    1. What is ecological succession?
      ::什么是生态继承?
    2. Describe the main difference between primary and secondary succession.
      ::说明一级和二级继承之间的主要区别。
    3. Give two examples of habitats that will go through primary succession.
      ::举两个将经历初级继承的生境的例子。
    4. What is a climax community?
      ::什么是高潮社区?
    5. Summarize how ideas about ecological succession and climax communities have changed.
      ::总结关于生态继承和高潮社区的想法是如何改变的。