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STANDARDS

CCSS: 6.SP.B.5.A

TEKS: 6.12C

Tilting Trees

eFesenko/Alamy Stock Photo

Most trees grow straight up. But not Cook pines! These 200-foot-tall trees can be found around the world. As botanist Jason Johns was studying them, he noticed something odd: The Cook pines in California always lean to the south.

Johns and his team studied the Cook pines on five continents and discovered that the trees always lean toward the equator. Additionally, the exact angle at which they lean depends on how far north or south of the equator they’re located.

Plants grow toward sunlight, but they can also sense forces like gravity and wind. According to Johns, we’re still learning how all of these factors affect plant growth. One explanation could be that the Cook pines are simply growing toward the sun. That’s because the sun doesn’t rise as high in the sky as you travel away from the equator.

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