Pedodiversity Plant托福听力原文翻译及问题答案

2023-05-19 09:26:59 来源：中国教育在线

Pedodiversity Plant托福听力原文翻译及问题答案

一、Pedodiversity Plant托福听力原文：

NARRATOR:Listen to part of a lecture in a plant ecology class.FEMALE PROFESSOR:So far we have covered biodiversity in the hard wood forest here in the upper peninsula of Michigan from a number of angles.We've looked at everything from how biodiversity relates to species stability,to competition for forests resources and more.

But now I want to discuss what's called pedodiversity.Pedodiversity is basically soil diversity.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.

So we look at soil chemistry.For example,how much nitrogen or magnesium there's in the soil in one spot.And we compare it with the chemistry of the soil a short distance away.Until recently,there hasn't been a whole lot of attention paid to pedodiversity.But that's changing rapidly.More and more studies are being done in these fields.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.A high degree of soil variability in a small area is common,particularly within forests.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.It generally has more diversity.Um,OK.There are three main causes of pedodiversity within old-growth forest here in our region of Michigan.One is tree species.Different species have different influences on soil formation and soil properties.For example,pine trees drop pine needles.And those needles add a lot of acid to the soil.The organic litter of another tree species might add less acid but more of something else.A lot of different types of trees in an area might mean more pedodiversity.Another cause?Gaps created when trees fall.You see,where there are gaps—open areas—in the forest,the soil there changes.Um,for instance,without a tree to absorb radiation from the Sun,to offer shade,the full intensity of that radiation reaches the ground.The soil where the tree used to be heats up.And without a tree to soak up moisture from the ground,the soil remains wetter than in the surrounding forest.With a higher temperature and more moist conditions,the process of organic matter decomposition speeds up.In other words,organic matter gets broken down and added into the soil more quickly in these gaps than in the surrounding forest.OK.And the third cause:trees being uprooted.When a tree is uprooted,it might fall into some other trees on its way down,thus falling only partway over.Or it might crash all the way down to the forest floor.Either way,if its roots are pulled up from out of the ground as the tree topples over,then there's usually a big hole—a pit—left in the ground where the roots used to be.

And there's still a lot of soil attached to the roots,clinging to the roots.As that soil is eventually shed from the roots by rain and wind and the movement of squirrels climbing around,things like that.Um...as the soil is shed,it drops down and forms a little hill of dirt—a mound.Pits and mounds have significantly different soil properties than other areas in the forest.You get a redistribution and mixing of soil as deep roots are ripped up from the ground.Rock fragments can be pulled up too,if they've gotten entangled with the roots over the years.So rock fragments from the subsoil can end up concentrated on the surface.There are forests management implications I want to point out.Forests management impacts soil quality.And when we better understand pedodiversity,we will be better able to predict the impact of forest management on soil.But in general,for positive impact,forest management practices should mimic natural forest processes.And the goal should be to promote pedodiversity,and through this,biodiversity in general.I have a handout,an article on pedodiversity in a section of forests near here.I want you to read it,because it makes a point that I've only touched on.From what I have been saying about the causes of pedodiversity,you might assume that the relationship between forest dynamics,what happens to the trees,and pedodiversity is a one-way street.As the article explains,forest dynamics affects pedodiversity.But pedodiversity also affects forest dynamics.It's worth bearing in mind.

二、Pedodiversity Plant托福听力中文翻译：

旁白：在植物生态学课上听一部分讲座。女教授：到目前为止，我们已经从多个角度涵盖了密歇根州上半岛的硬木森林的生物多样性。我们研究了从生物多样性与物种稳定性的关系到森林资源的竞争等等。

但现在我想讨论什么叫儿童多样性。土壤多样性基本上是土壤多样性。当我们分析一个区域内的土壤多样性时，我们测量的是土壤性质的变异程度，以及特定区域内有多少不同类型的土壤。

所以我们来看看土壤化学。例如，一个地点的土壤中有多少氮或镁。我们将其与不远处土壤的化学性质进行比较。直到最近，对儿童多样性的关注还不多。但这种情况正在迅速变化。在这些领域正在进行越来越多的研究。生物多样性和土壤多样性之间有联系，土壤和动植物之间有明显的关系，这就是为什么在森林管理中应该考虑土壤多样性。小面积的土壤变异性很高，特别是在森林中。如果将森林土壤与非森林土壤进行比较，则森林土壤的变异性可能更大。它通常具有更多的多样性。嗯，好的。在我们密歇根州的老森林中，有三个主要原因导致了土壤多样性。一是树种。不同物种对土壤形成和土壤性质的影响不同。例如，松树掉落松针。这些针头给土壤添加了大量的酸。其他树种的有机垃圾可能会添加更少的酸，但会添加更多的其他物质。一个地区有许多不同类型的树木可能意味着更多的土壤多样性。另一个原因？树木倒下时会产生空隙。你看，在森林中有空隙的地方，土壤会发生变化。嗯，比如说，如果没有一棵树来吸收来自太阳的辐射，提供阴凉，辐射的全部强度就会到达地面。这棵树以前生长的地方的土壤变热了。如果没有一棵树从地面吸收水分，土壤比周围的森林更湿润。随着温度和湿度的升高，有机物的分解过程加快。换句话说，有机物质在这些空隙中分解和添加到土壤中的速度比在周围森林中更快。好的。第三个原因：树木被连根拔起。当一棵树被连根拔起时，它可能会在倒下的过程中掉到其他树上，因此只会掉到一半。或者它可能一路坠落到森林地面。不管是哪种情况，如果树倒下时，它的根被拔出地面，那么通常会有一个大洞-一个坑，在地面上留下根。

还有很多土壤附着在根部，附着在根部。由于雨水和风以及松鼠四处攀爬的运动，土壤最终会从根部脱落。嗯…当土壤脱落时，它会落下来形成一个小土丘-一个土丘。坑和土丘的土壤特性与森林中的其他区域明显不同。当深根从地上被撕开时，土壤会重新分布和混合。岩石碎片也可以被拉起，如果这些年来它们与树根纠缠在一起。因此，来自底土的岩石碎片最终会集中在地表。我想指出森林管理的影响。森林管理影响土壤质量。当我们更好地理解土壤多样性时，我们将能够更好地预测森林管理对土壤的影响。但总的来说，为了产生积极影响，森林管理做法应模仿自然森林过程。目标应该是促进土壤多样性，并通过这一点，促进总体生物多样性。我有一份讲义，一篇关于附近一片森林中的土壤多样性的文章。我想让你们读这篇文章，因为它提出了一个我刚刚提到的观点。从我所说的土壤多样性的原因来看，你可能会认为森林动态、树木的变化和土壤多样性之间的关系是单向的。正如本文所解释的，森林动态影响土壤多样性。但土壤多样性也影响森林动态。这是值得铭记的。

三、Pedodiversity Plant托福听力问题：

Q1:1.What does the professor mainly discuss?

A.Causes of soil diversity in old-growth forests

B.The results of a recent research study in a Michigan forest

C.The impact of pedodiversity on forest growth

D.How forest management affects soil diversity

Q2:2.According to the professor,in what way is the soil in forested areas generally different from soil in other areas?

A.In forested areas,the soil tends to be warmer and moister.

B.In forested areas,the chemistry of the soil changes more rapidly.

C.In forested areas,there is usually more variability in soil types.

D.In forested areas,there is generally more acid in the soil.

Q3:3.What does the professor suggest are the three main causes of pedodiversity in the old-growth hardwood forests she discusses?[Click on 3 answers.]

A.The uprooting of trees

B.The existence of gaps

C.Current forest-management practices

D.Diversity of tree species

E.Changes in climatic conditions

Q4:4.Why does the professor mention radiation from the Sun?

A.To point out why pits and mounds have soil with unusual properties

B.To indicate the reason some tree species thrive in Michigan while others do not

C.To give an example of a factor that cannot be reproduced in forest management

D.To help explain the effects of forest gaps on soil

Q5:5.Why does the professor consider pedodiversity an important field of research?

A.It has challenged fundamental ideas about plant ecology.