Ecologists call this row of biological dominoes a trophic cascade.

生态学家把这一系列生多米诺骨牌效应称级联。

The organisms in a food chain are classified into their trophic level depending on their feeding behavior.

食链中的生根据它们的摄食行被划分不同的等级。

From the producers, the second trophic level is the herbivores, the organisms that eat the plants.

从生产者来看，第二个次是食草动，即以植食的生。

Decomposers can also be considered to occupy their own trophic level.

分解者也可以被据自己的级。

The impact of a predator down through the food web all the way to plants is called a trophic cascade.

捕食者沿食链往下一路直达植的影响被称“级联”。

These categories are not strictly defined, as many organisms feed on several trophic levels.

这些类别没有严格定义，因许多生以几种水平食。

Now let's look at the trophic levels in this community.

现在让我们来看看这个群落的水平。

The number of steps an organism is from the start of the food chain is a measure of its trophic level.

一个生体从食链开始的步骤数是衡量其水平的标准。

The first trophic level is the primary producers, the grass.

第一是初级生产者，草。

Scientists call this type of carefully balanced relationship between different species a trophic cascade.

科学家将这种不同种间精心维持的平衡关系称“级联”。

This carefully balanced trophic cascade has fallen apart in Northern California.

这种精心维持的生态级联效应在北加州已经瓦解。

We've restored the trophic interactions that we want to see in a rain forest.

我们已经恢复了我们希望在雨林中看到的相互作用。

They fit right in, in the trophic cascade.

它们完美地融入了级联中。

Another is that there's generally more food easily available at lower trophic levels.

另一个原因是较低级通常更容易获得更多的食。

Exercise increases brain trophic factors which are necessary for cognition.

锻炼能提升大脑因子，这对知功能至关重要。

The third trophic level is secondary consumers which is the example of fox.

第三个等级是次级消费者，以狐狸例。

The trophic cascade fell out of balance.

食链级联效应失衡了。

So this would be the fourth trophic level or we'd call this a third level consumer.

因此，这将是第四级，或者我们称之第三级消费者。

And so we should define what a trophic level is first.

因此，我们首先应该定义什么是级。

We've included decomposers in a trophic level five, in this example, it's the fungi.

我们把分解者包括在级五级，在这个例子中是真菌。