字幕列表 影片播放 列印英文字幕 Meet Hyperion! This impressive looking plant currently holds the title of “world's tallest tree.” Its name, “Hyperion,” means “the high one”... and that's no joke! Hyperion's top branches tower over all of the trees around it. Its very tippy-top is one hundred fifteen meters above the ground. That's taller than an American football field is long...about twice as tall as the Statue of Liberty in New York City...and about fifteen meters taller than the clock tower in London that houses Big Ben. And it's taken a long time for Hyperion to get so big. Scientists think that it's between 700 and 800 years old! Hyperion belongs to a group of trees called redwoods. Redwoods are pretty picky about where they live—they only grow in a few places around the world. Hyperion's home is somewhere in Northern California, in the Redwood National and State Parks. And I say “somewhere” because, except for a few people, no one knows exactly where Hyperion is! Hyperion was discovered by two people hiking through the park. After some scientists measured the tree and crowned it as the world's tallest, everyone who knew where Hyperion was decided to keep its location a secret. They knew that a lot of people would want to see the world's tallest tree, I mean, who wouldn't? … but they also knew that too many people walking around the tree might damage its roots or trunk. So they decided that the only way to make sure the tree stayed safe was to let it stay hidden. Fortunately, there are lots of other redwoods to see all around it ...as well as lots of other really big trees that are related to the redwood. Another kind of humungous tree is the giant sequoia. Both the giant sequoia and the redwood live for a long time...grow to be very tall...and in some cases...get to be very wide. So there must be something special about these trees! Why are they able to grow so large and so tall? And the answer is...kind of another secret, because no one knows for sure! Scientists have some pretty good guesses, though. The first is that these trees are really good at staying healthy. All kinds of trees can get diseases that make them sick...just like you and I can catch a cold, or the flu or something else. Redwoods make a chemical that helps protect them from diseases. This chemical also tastes really bad to animals like insects. So bugs that might normally like to snack on wood or leaves are likely to stay away from redwood trees! The outer covering of the tree, called the bark, is also very thick in redwoods...in some cases up to thirty centimeters thick. That's about the length of a ruler that you might have in school or at home! And the bark is really stringy and tough -- so tough, in fact, that it doesn't burn very easily. So forest fires that damage other kinds of trees probably won't hurt these kinds of trees as much. Another reason that scientists think that redwoods grow so tall is because of where they live. Redwoods need water. Lots of water. So they grow where it's cool and very wet. When it's not raining or snowing where redwoods live, it's usually misty or foggy. If you've ever been outside on a foggy day, you know that the air can feel kind of wet. That's because fog is made of lots of tiny drops of water. Now, redwoods have special leaves called needles. And redwood needles can do something really cool. They can actually take water right out of the fog, so the tree doesn't have to get all of its water from its roots. This way, the tree has two ways to get water … through its needles and its roots ...instead of just one. And there's more to growing tall than just getting lots of water. Trees also need food, and they get some of the food they need to grow from the soil. Just like healthy foods like fruits and vegetables give us what we need to grow, the soil in Northern California is kind of like those healthy foods — full of the things that trees need to grow! But here's something strange about the world's tallest tree: Even though Hyperion has lots of water, thick bark, and can get good things from the soil—it isn't growing any taller! Scientists think that the tree stopped growing, because some woodpeckers damaged the top of it. So, who knows? Maybe someday there'll be another tree that takes over the title as “World's Tallest”...and maybe you'll be the one to find it! We love getting questions here at the Fort! So if you have one...ask a grownup to help you leave a comment down below, or to send us an email to kids@SciShow.com! Thanks and we'll see you next time!
A2 初級 美國腔 世界上最高的树(The World's Tallest Tree! | Science for Kids) 20 2 joey joey 發佈於 2021 年 05 月 10 日 更多分享 分享 收藏 回報 影片單字