英语听力—环球英语 1139 Planting Ancient Trees（打印版）

　　And I'm Liz Waid. Spotlight uses a special English method of broadcasting. It is easier for people to understand no matter where in the world they live.

　　Now imagine that this tree is not JUST tall. It is also WIDE - more than four meters wide. Can you imagine a tree this large? It is large enough to drive a car through. It is large enough to build a house in. And trees like this do not just exist in your imagination. This is the Sequoia tree. And Sequoia trees are found in northern California, in the United States.

　　Northern California has some of the oldest and largest trees in the world – including the Sequoia trees. These trees can live to be more than two thousand years old. And like many other large and ancient trees, these trees are at risk. They are at risk of dying out completely and becoming extinct.

　　Many groups around the world are working to save ancient trees like the Sequoias. Today's Spotlight is on one of these groups: the Archangel Ancient Tree Archive. This organization wants to reproduce these ancient trees. They believe these trees can help save the environment.

　　Many things threaten ancient trees. In many places, people want to cut down ancient trees. Some people want to use the land for other things - like expanding cities, or farms. Other people want to use the wood for building or burning. Changes to the environment also threaten ancient trees. Like all trees, disease, pollution, and changes in the weather can weaken or kill the trees.

　　David Milarch is one of the creators of the Archangel Ancient Tree Archive. He talked to the Associated Press about the world's old growth forests. These forests contain the world's oldest trees. Milarch said,

　　The Archangel Ancient Tree Archive has a goal. They want to re-produce and re-plant thousands of the largest, oldest and most environmentally helpful ancient trees. The scientists at the Archive start this process by collecting small pieces of ancient living trees. They use these tree pieces to collect and record the trees' genetic information. They also plant these very small pieces of ancient tree in a liquid mixture. The mixture contains vitamins, minerals and other chemicals needed for the tree pieces to grow. Soon, these pieces of ancient tree will grow new roots - they will become very small trees. This process of re-producing trees is called cloning. Genetically, these new trees are exactly the same as the original, ancient tree.

　　The Archive has completed this process with sixty different kinds of trees. For all these trees, they have collected genetic information and created new clones. Their results are a living collection or library of ancient tree information. Their goal is to collect genetic information and make clones of two hundred different kinds of ancient trees. The scientists hope that this collection will be useful for study now and in the future.

　　But this is only the first part of the Archive's work! When the very small trees grow large enough, the scientist move them to new containers. These containers are filled with dirt. In the dirt, the very small clones will grow into larger young trees. Soon, they will be ready to plant in the ground. Then, the Archive will encourage people to buy and plant the trees. They hope that colleges, businesses and cities will buy the young trees and plant them in their areas.

　　The Archangel Ancient Tree Archive believes that planting these new trees can help to heal the environment. This is because they choose trees that are especially helpful to the environment. Some of the trees they clone capture toxins, or bad substances, from the soil. They can make polluted soil healthy again. The trees are big and strong enough to hold the toxins from the environment.

　　Other trees, like the Sequoias and Giant Redwoods from California, are able to store large amounts of carbon. Carbon dioxide is a gas that is a major cause of climate change. These trees are able to capture large amounts of carbon from the air. They also give off great amounts of oxygen - a gas necessary for all life on earth. Dr. William Libby is a scientist who advises the Archive. He also talked to the Associated Press about this work. He explains,

　　"California's redwoods and sequoias are the world's largest trees. They are the best for holding carbon because of their size, quick growth and strength. The longer a tree lives, the longer it can keep carbon from entering the atmosphere."

　　However, there are some concerns about the Archive's work. Some people wonder if it will really save ancient forests. The Archive hopes to plant individual trees. But these trees will not likely be in large groups - like forests. Instead, they will be planted separately. Although this does create new individual trees, it does not re-produce the important forest environment. Also, some people may not plant the trees in their native areas. Scientists worry that these trees will not survive or be as helpful in other places.

　　One final concern is about the way the Archive is growing the trees. Cloning trees is not a new process. However, cloning ancient tree is. This is because cloning young trees is much easier. Ancient trees are difficult to re-produce. The Archive's new method of cloning ancient trees is amazing. But like all cloned trees, the new, young trees are genetically identical to the parent trees. They are exactly the same in every way. This means that if a new disease is able to attack and kill an ancient tree, it will be able to attack all its clones. When trees naturally re-produce, each new tree is a little different. And this can protect new generations of trees from disease.

　　These concerns are important. But William Libby argues that the Archive is doing important work too. They are collecting and saving the genetic information of these ancient and useful trees - information necessary for future research. They are also encouraging people to plant trees and care for ancient forests now - acts that can fight climate change before it is too late!

　　To learn more about the Archangel Ancient Tree Archive, visit our website at http://www.radioenglish.net There., you can also share your opinion about the Archive. Is it helping to save ancient forests?

　　The writer of this program was Erin Layman. The producer was Joshua Leo. The voices were from the United States. All quotes were adapted for this program and voiced by Spotlight. This program is called "Planting Ancient Trees." You can hear this program again and read it on the Internet at http://www.radioenglish.net This .program is called "Planting Ancient Trees."

英语听力—环球英语 1139 Planting Ancient Trees（在线收听）