Amazing Places

No Matter Where They Grow, Cook Pines Lean Toward the Equator

The Cook pine has a secret. You'll find the tall, slender trees on five different continents, as far south as New Zealand and Australia, and as far north as California. If you look closely, no matter where you see them, they're all leaning toward the equator. All of them. Leaning.

The row of winding Cook pines in Peradeniya botanical garden.

Lean Back

While studying the Cook pine, researcher Matt Ritter noticed that all the trees he observed had a distinct tilt pointing south. Wondering if that was a local phenomenon or something specific to the species, he called a colleague in Australia to compare notes. Incredibly, he learned that all the Aussie trees had a lean to the north.

That launched a study of 256 Cook pines in 18 locations across five continents. All of the trees, no matter where they were, leaned toward the equator. Ritter described the pattern as "shockingly distinct." Perhaps even more interesting was the discovery that the further the tree was from the equator, the more it slanted. The deepest lean came in at 40 degrees.

Curved pine trees at the Royal Botanical Garden

Lean On, Tree

While other plants like the yucca have been known to tilt uniformly, the Cook pine is the first known tree to exhibit such a strong pattern. Typically, trees that tilt self-correct to create more symmetry, so they continue to grow upward toward the sun. That makes the Cook's lean even more unusual.

Ritter and his team have hypothesized two reasons for the unusual, but ubiquitous tilt: either it's a genetic predisposition that has lasted several centuries while the tree was cultivated in different locations beyond its original Pacific home, or it's their way to absorb more sunlight at higher altitudes.

How Many Trees Are There?

Key Facts In This Video

  1. 80% of terrestrial species live in trees, and 1.6 billion people rely on forests for their livelihood. 01:23

  2. A 2015 study estimated that there are 3 trillion trees on Earth, which is around 420 trees for every human. 02:19

  3. Fewer trees could lead to less rain. 03:18

Written by Jamie Ludwig July 12, 2017

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