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第一段
1 .Listen to part of a lecture in a plant ecology class.
听一段植物生态学课程上的演讲
第二段
1 .So far we have covered biodiversity in the hard wood forest here in the upper peninsula of Michigan from a number of angles.
目前为止我们从几个角度讲了在密歇根半岛北部硬木森林中的生物多样性。
2 .We've looked at everything from how biodiversity relates to species stability, to competition for forests resources and more.
我们看了从生物多样性到物种稳定性，再到竞争森林资源等等。
第三段
1 .But now I want to discuss what's called pedodiversity.
但是现在我想讨论一下pedodiversity。
2 .Pedodiversity is basically soil diversity.
Pedodiversity就是土壤多样性。
3 .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.
当我们分析一个地方的土壤多样性，我们要测量土壤性质有多么多样，以及一个地方有几种不同的土壤。
第四段
1 .So we look at soil chemistry.
我们研究土壤的化学成分。
2 .For example, how much nitrogen or magnesium there's in the soil in one spot.
比如，一个地方的土壤中有多少氮元素和镁元素。
3 .And we compare it with the chemistry of the soil a short distance away.
然后我们把它和短距离内土壤成分进行对比。
第五段
1 .Until recently, there hasn't been a whole lot of attention paid to pedodiversity.
直到最近，还没有很多对土壤多样性的关注。
2 .But that's changing rapidly.
但是改变正在迅速发生
3 .More and more studies are being done in these fields.
这一领域出现了越来越多的研究
4 .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有联系——土壤与植物群和动物种类之间明显的关系，因此土壤多样性真的应该被考虑到森林管理之中。
第六段
1 .A high degree of soil variability in a small area is common, particularly within forests.
小范围内高度的土壤多样性是常见的，尤其在森林中。
2 .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.
。如果你把森林中的土壤和非森林中土壤进行比较， 森里土壤的变化很可能更多。
3 .It generally has more diversity.
森林土壤通常更多样。
第七段
1 .Um... OK. There are three main causes of pedodiversity within old-growth forest here in our region of Michigan.
好的，在密歇根我们周围的古老森林中有三个造成土壤多样性的主要原因。
第八段
1 .One is tree species.
一是树木种类。
2 .Different species have different influences on soil formation and soil properties.
不同树种对土壤的形成和土壤性质有不同的影响。
3 .For example, pine trees drop pine needles.
比如，松树掉下松针。
4 .And those needles add a lot of acid to the soil.
这些松针增加了土壤的酸性。
5 .The organic litter of another tree species might add less acid but more of something else.
。其他品种的树掉下来的有机物可能酸性弱些但含有更多的其他成分。
6 .A lot of different types of trees in an area might mean more pedodiversity.
一个地区有许多不同的树种可能意味着更多的土壤多样性。
第九段
1 .Another cause? Gaps... created when trees fall.
其他原因呢？树倒后产生的缝隙。
2 .You see, where there are gaps, open areas in the forest, the soil there changes.
你看在森林中的缝隙或开阔的空间里，土壤会变化。
3 .Um... for instance, without a tree to absorb radiation from the Sun, to offer shade, the full intensity of that radiation reaches the ground.
比如，没有树吸收太阳辐射并形成树荫时，辐射的全部强度都到了地面上。
4 .The soil where the tree used to be heats up.
原来有树的土壤温度升高。
5 .And without a tree to soak up moisture from the ground, the soil remains wetter than in the surrounding forest.
而且没有树木吸收地上的水分，土壤比周围的更湿润。
6 .With a higher temperature and more moist conditions, the process of organic matter decomposition speeds up.
当温度变高，湿度变大时，有机物分解的过程加快。
7 .In other words, organic matter gets broken down and added into the soil more quickly in these gaps than in the surrounding forest.
换句话说，与周边森林相比，缝隙中的有机物被分解并融入土壤的速度更快。
第十段
1 .OK. And the third cause: trees being uprooted.
好的。第三个原因是树根暴露。
2 .When a tree is uprooted, it might fall into some other trees on its way down, thus falling only partway over.
当树被连根拔起，它可能倒在其他树上，因此只倒了一半。
3 .Or it might crash all the way down to the forest floor.
或者它可能会落到森林中的地面上。
4 .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.
无论那种情况，树倾斜时如果根部从土壤中露出，那么通常会产生一个大洞，在原有树根的地方留下一个坑。
5 .And there's still a lot of soil attached to the roots, clinging to the roots.
并且还有很多土壤留在树根上，附在上面。
6 .As that soil is eventually shed from the roots by rain and wind and the movement of squirrels climbing around, things like that.
于是在风雨或松鼠攀爬的作用下，土壤最终会掉下来。
7 .Um... as the soil is shed, it drops down and forms a little hill of dirt, a mound.
当土掉下来后，会形成一个小土山，一个土丘。
第十一段
1 .Pits and mounds have significantly different soil properties than other areas in the forest.
与森林中其他地方比，坑和丘有明显不同的土壤性质。
2 .You get a redistribution and mixing of soil as deep roots are ripped up from the ground.
当深处的树根从土中被崛起，土壤发生重新分布和混合。
3 .Rock fragments can be pulled up too, if they've gotten entangled with the roots over the years.
年来缠绕在树根上的岩石碎片也可能被挖掘出来。
4 .So rock fragments from the subsoil can end up concentrated on the surface.
于是底土中的碎岩石可能最终会聚集于地表。
第十二段
1 .There are forests management implications I want to point out.
我想指出这对森林管理的意义。
2 .Forests management impacts soil quality.
森林管理影响土壤的质量。
3 .And when we better understand pedodiversity, we will be better able to predict the impact of forest management on soil.
而当我们更好的了解土壤多样性时，我们就能更好的预测森林管理对土壤的影响。
4 .But in general, for positive impact, forest management practices should mimic natural forest processes.
但是总体来说，为了积极的影响，森林管理应该模仿森林中自然的过程。
5 .And the goal should be to promote pedodiversity, and through this, biodiversity in general.
。而目标应该是提高土壤多样性，而且通过它来提高整体的生物多样性。
第十三段
1 .I have a handout, an article on pedodiversity in a section of forests near here.
我有一个讲义，上面有关于附近森林中土壤多样性的一篇文章。
2 .I want you to read it, because it makes a point that I've only touched on.
我希望你们阅读这篇文章，因为它介绍了我简单讲解过的内容。
3 .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.
通过我所讲的造成土壤多样性的原因，你们可能会认为森林动态，就是发生在树上的事情，与土壤多样性的关系是单方向的影响。
4 .As the article explains, forest dynamics affects pedodiversity.
如文章所言，森林动态影响土壤多样性。
5 .But pedodiversity also affects forest dynamics.
但是土壤多样性同样影响森林动态。
6 .It's worth bearing in mind.
这是我们值得记住的。