The Impact of Fire on Biodiversity托福紅Delta聽力原文翻譯及問題答案

The Impact of Fire on Biodiversity托福紅Delta聽力原文翻譯及問題答案， 今天中國教育在線就來為大家分析這個問題。

一、The Impact of Fire on Biodiversity 托福聽力原文：

We all know that change is a fact of life. For North American forests, change often comes in the form of fire. After thousands of years of living with fire, many plant and animal species have come to depend on its periodic presence. Without fire, ecosystems can stagnate and lose their diversity of life.

In the past, before we understood the role that fire plays in the natural life cycle of our forests, our goal was to prevent or contain all forest fires. For almost ninety years, our land management agencies tried to eliminate fires. In many cases, we protected the trees, but at the expense of the forest community. Now we know that fire is a natural agent that rejuvenates a forest. And we know that fire suppression can actually threaten the lives of healthy trees. So, today our policy is to allow natural fires to burn under close observation and to set “prescribed” fires under carefully controlled conditions.

Research shows that forests go through natural fire cycles. Periodic fires are necessary for several reasons. Fire removes nutrients from standing dead trees and returns them to the earth, where they become available to the root systems of new trees. Fire also opens the forest to sunlight. Openings in the tree cover benefit a variety of wildlife by stimulating the growth of lush green plants, which are eaten by several species of animals.

Fire is nature’s way of controlling insect infestations. By contrast, fire suppression preserves dead wood that harbors insect pests, like the larvae of the mountain pine beetle. These beetle larvae feed on the inner bark of some trees, which blocks the flow of nutrients and eventually kills the trees. When dead trees burn during periodic outbreaks of fire, the heat kills off great numbers of beetles and larvae, providing a natural method of pest control.

The exclusion of fire from the ecosystem is creating unhealthy, overcrowded forests that contain more fuel for larger, more severe fires. For example, when a huge fire threatened a grove of giant sequoias in California, observers noted that the flames were fed by dead wood and combustible debris that had accumulated on the forest floor over years of fire suppression.

A large-scale, intense forest fire causes more significant impacts to water, soil, and air resources than a managed prescribed fire. Prescribed fire, or controlled fire, has several purposes. Chiefly, it reduces the hazard of more serious wildfires by periodically burning accumulated weeds, brush, and other plants. If done carefully, prescribed burning also releases nutrients back into the soil and controls insect pests.

In Florida, prescribed burns are carried out every three to five years in one of the national forests. These controlled burns keep the forest open and reduce the growth of problem species.

We recognize that fire is a natural and revitalizing process that enhances the diversity of the forest. However, we also know that fire has consequences. There may be smoky, hazy skies and patches of blackened forest for a long time after a fire. There’s also the risk of a fire becoming too large and threatening inhabited areas. But we have to accept these realities if our forests are to retain their ecological balance.

二、The Impact of Fire on Biodiversity 托福聽力中文翻譯：

我們都知道改變是生活的一個事實。對于北美森林來說，變化往往以火的形式出現(xiàn)。在與火共存數(shù)千年之后，許多動植物物種已經(jīng)開始依賴火的周期性存在。沒有火，生態(tài)系統(tǒng)就會停滯，失去生命的多樣性。

過去，在我們了解火災(zāi)在森林自然生命周期中所起的作用之前，我們的目標是預(yù)防或控制所有森林火災(zāi)。近90年來，我們的土地管理機構(gòu)一直在努力撲滅火災(zāi)。在許多情況下，我們保護了樹木，但以犧牲森林社區(qū)為代價?，F(xiàn)在我們知道火是一種天然的媒介，可以使森林恢復(fù)活力。我們知道，滅火實際上會威脅健康樹木的生命。因此，今天我們的政策是允許自然火災(zāi)在密切觀察下燃燒，并在精心控制的條件下設(shè)置“規(guī)定”的火災(zāi)。

研究表明，森林經(jīng)歷了自然火災(zāi)循環(huán)。有幾個原因需要定期火災(zāi)?；饛目菟赖臉淠局腥コB(yǎng)分，并將其返回地球，在那里新樹木的根系可以利用這些養(yǎng)分?；疬€使森林向陽光開放。樹木覆蓋層的開口通過刺激郁郁蔥蔥的綠色植物的生長，使多種野生動物受益，這些植物被多種動物吃掉。

火是大自然控制蟲害的方式。相比之下，滅火可以保護藏匿害蟲的枯木，比如山松甲蟲的幼蟲。這些甲蟲幼蟲以一些樹木的內(nèi)部樹皮為食，這會阻礙養(yǎng)分的流動，最終殺死樹木。當(dāng)枯樹在周期性的火災(zāi)中燃燒時，高溫殺死了大量的甲蟲和幼蟲，提供了一種自然的害蟲控制方法。

將火排除在生態(tài)系統(tǒng)之外正在造成不健康、過度擁擠的森林，為更大、更嚴重的火災(zāi)提供更多燃料。例如，當(dāng)一場大火威脅到加利福尼亞州一片巨大的紅杉林時，觀察家們注意到，大火是由多年滅火后堆積在森林地面上的枯木和可燃碎片引發(fā)的。

大規(guī)模、強烈的森林火災(zāi)對水、土壤和空氣資源的影響比管理規(guī)定的火災(zāi)更大。規(guī)定火災(zāi)或控制火災(zāi)有多種用途。主要是，它通過定期焚燒積累的雜草、灌木叢和其他植物來減少更嚴重野火的危害。如果小心地進行，規(guī)定的焚燒也會將養(yǎng)分釋放回土壤中，并控制害蟲。

在佛羅里達州，每三到五年在一片國家森林中進行一次規(guī)定的焚燒。這些受控的燃燒保持了森林的開放性，減少了問題物種的生長。

我們認識到，火災(zāi)是一個自然和恢復(fù)活力的過程，它增強了森林的多樣性。然而，我們也知道火災(zāi)有其后果?；馂?zāi)發(fā)生后很長一段時間內(nèi)，可能會有煙霧彌漫的天空和大片發(fā)黑的森林。還有火災(zāi)變得太大并威脅居住區(qū)的風(fēng)險。但是，如果我們的森林要保持生態(tài)平衡，我們就必須接受這些現(xiàn)實。

三、The Impact of Fire on Biodiversity 托福聽力問題：

Q1:

What is the main idea of the talk?

A.Forest management agencies have eliminated forest fire.

B.Fire contributes to the beauty and mystery of the forest.

C.Fire revitalizes the forest and promotes a diversity of life.

D.Forest fire limits the amount of habitat taken by humans.

Q2:

What does the instructor mean by this statement:

A.Fire prevention has actually damaged the forest ecosystem.

B.Every tree in the forest passes through its own life cycle.

C.Protecting one species will benefit every other species.

D.Foresters will never fully understand the laws of nature.

Q3:

According to the instructor,why is periodic fire necessary to forest ecosystems?

Click on two answers.

A.Fire releases nutrients into the soil.

B.Fire creates employment for firefighters.

C.Fire controls insect pests that harm trees.

D.Fire reduces water and air pollution.

Q4:

According to the instructor,how does the elimination of fire endanger the forest?

A.Insect populations die without the heat provided by fire.

B.Dead wood and litter accumulate as fuel for large fires.

C.Too many people move into the forest,destroying wildlife habitat.

D.Animal populations grow too fast for the forest to support them.

Q5:

What is prescribed fire?

A.Fire that is caused by lightning

B.Fire that humans carefully manage

C.Fire that inspires artists and writers

D.Fire in areas where people live

Q6:

Why does the instructor say this:

A.To explain why good firefighters are needed

B.To tell about his own observation of a large fire

C.To find out if students have ever seen a fire

D.To give examples of the negative effects of fire

四、The Impact of Fire on Biodiversity 托福聽力答案：

A1:正確答案：C

A2:正確答案：A

A3:正確答案：AC

A4:正確答案：B

A5:正確答案：B

A6:正確答案：D

>> 雅思 托福 免費測試、量身規(guī)劃、讓英語學(xué)習(xí)不再困難<<