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托福TPO-29 Lecture 1(上)

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Listen to part of a lecture in a plant ecology class.

听一段植物生态学课程。

So far we have covered biodiversity in the hard wood forest here in the upper peninsula of Michigan from a number of angles.

目前为止,我们已经从多个角度讲了密歇根上部半岛阔叶林中的生物多样性。

We've looked at everything from how biodiversity relates to species stability, to competition for forests resources and more.

我们已经讲完全部内容了,从生物多样性是怎样联系到物种稳定性,到竞争森林资源等。

But now I want to discuss what's called pedodiversity.

今天我想讲讲土壤多样性。

Pedodiversity is basically soil diversity.

土壤多样性即土壤的多样性。

植物生态学.jpg

When we analyze pedodiversity within an area, we are measuring how much variability there is in soil properties and how many different types of soil there are in a particular area .

我们分析某个地区的土壤多样性时,我们会测量土壤性质有多少可变性,及在某个地区内有多少种不同的土壤类型。

So we look at soil chemistry, for example, how much nitrogen or magnesium there's in the soil in one spot.

我们来看看土壤的化学性质,比如说,在某个地方的土壤里有多少氮和镁。

And we compare it with the chemistry of the soil a short distance away.

然后我们将其与附近土壤的化学性质作比较。

Until recently, there hasn't been a whole lot of attention paid to pedodiversity.

直到最近,人们才开始关注土壤多样性。

But that's changing rapidly.

但情况迅速改变。

More and more studies are being done in these fields.

越来越多人在此领域做研究。

There's a link between biodiversity and pedodiversity, an obvious relationship between soils and flora and fauna, which is why pedodiversity really should be considered in forest management .

生物多样性和土壤多样性之间是有联系的,土壤和动植物之间的关系也非常明显,这就是为什么在森林管理中,土壤多样性也需要考虑在内。

A high degree of soil variability in a small area is common, particularly within forests.

小范围地区内的土壤变化程度很高是很常见的,特别是在森林中。

If you compare soils from a forest with soils that don't come from a forest, the amount of variability will most likely be greater in the forest's soil.

如果你比较森林土壤和非森林土壤,前者的变化程度很可能更高。

It generally has more diversity.

一般森林土壤更多样。

Um...OK. There are three main causes of pedodiversity within old-growth forest here in our region of Michigan.

在我们所处的密歇根区域的老龄森林中,造成土壤多样性的原因主要有三。

One is tree species.

一是树种。

Different species have different influences on soil formation and soil properties.

不同的树种对土壤成分和土壤性质有不同的影响。

For example, pine trees drop pine needles.

比如说,松树会掉落松针。

And those needles add a lot of acid to the soil.

这些松针给土壤增加了不少酸性。

The organic litter of another tree species might add less acid but more of something else.

另一种树产生的有机废物可能不会给土壤增加这么多酸性,但会增加别的东西。

A lot of different types of trees in an area might mean more pedodiversity.

若在某个区域有很多种不同的树,很有可能意味着这儿的土壤多样性程度很高。

Another cause? Gaps ... created when trees fall.

另一个原因?空地,当树木倒下后就会产生空地。

You see, where there are gaps, open areas in the forest, the soil there changes.

在森林中有空地(开放区域)时,那儿的土壤就会发生改变。

Um... for instance, without a tree to absorb radiation from the Sun, to offer shade, the full intensity of that radiation reaches the ground.

举个例子吧,(如果)没有树来吸收太阳辐射,没有树遮阴,太阳辐射以最大强度到达地面。

The soil where the tree used to be heats up.

树木曾经所在地的土壤就会升温。

And without a tree to soak up moisture from the ground, the soil remains wetter than in the surrounding forest.

而且没有了树来吸收地里的水分,这儿的土壤就会比周围森林(的土壤)更湿润。

重点单词   查看全部解释    
diversity [dai'və:siti]

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n. 差异,多样性,分集

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absorb [əb'sɔ:b]

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vt. 吸纳,吸引 ... 的注意,吞并

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formation [fɔ:'meiʃən]

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n. 构造,编队,形成,队形,[地]地层

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particular [pə'tikjulə]

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adj. 特殊的,特别的,特定的,挑剔的
n.

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obvious ['ɔbviəs]

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adj. 明显的,显然的

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intensity [in'tensiti]

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n. 强烈,强度

 
pine [pain]

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n. 松树,松木
vi. 消瘦,憔悴,渴望

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ecology [i:'kɔlədʒi]

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n. 生态学

 
variability [.vɛəriə'biliti]

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n. 易变,变化性,变异性

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stability [stə'biliti]

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n. 稳定性,居于修道院

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