TIL: The Trees That Point To The Equator

ruth-girl (75)in #steemstem • 7 years ago (edited)

Ok, when it comes to navigation there are many misunderstood urban legend scout tricks that guarantee you you're getting lost in the forest and eaten up by the coyotes (wolves are slowly being banished by them according to @sustainablyyours' post, have a read if you'd like). Such survival tips include myths like "lichen and mosses growing on the north side of tree trunks" (yeah, that is a lie, I've told you again in the past).

Even though such "natural signs" are not always correct, there is one tree species that seems to prove the myths wrong and that is...

Image from: wikipedia.org - Author, my LifeShow - License, CC BY 2.0

The Cook Pine Tree

Originating from New Caledonia (in the southwestern Pacific Ocean), Araucaria columnaris (AKA Cook pine, New Caledonia pine, Cook araucaria, coral reef araucaria and columnar araucaria) is a conifer and a member of the Araucariaceae family. It is a conical tree that can reach up to 60 metres in height (in its original habitat). Its grey bark is resinous, rough and made out of thin strips. Its branches are short and almost always horizontally attached to the trunk, while horizontal branchlets with green, pointy leaves that overlap each other grow on them. [1]

The Weirdness

Those trees did not stay in New Caledonia, but spread throughout the world. So, one day professor Matt Ritter (Cal Poly University, California) decided to write a book on the trees of California. While working on his project, he came across the Cook pines of his area and had a strange revelation. The pines would lean to the North. [2]

Ritter was curious to see if this was the case solely in California. He contacted colleagues in Australia and asked to check if Cook pines there were no so "straight" as well. The answer was positive and as a result, Ritter and his colleagues conducted a study.

They observed "256 trees on five continents in 18 different regions (distinct areas more than 500 km from each other)" [4]. The results (with a 9% deviation) showed that trees in the northern hemisphere would lean south, whereas trees in the southern hemisphere would lean north. Even more surprising was the realization that the farther the trees were from the equator, the more they leaned. [4]

Why?

The reasons for this behavior remain still unexplained. Trees, normally, grow vertically responding to their call of the opposing light and gravitational forces. But in some cases, where the environment is not friendly, we can see trees develop non-vertically (when there is competition for light or the light source is not directly upwards, or when intense mechanical forces are applied on them, like strong winds and snow). [4]

Image from: commons.wikimedia.org - Author, MacKhayman - License, CC BY-SA 3.0

Speculations mention that this behavior could be a phototropic response or may be related to gravitational or magnetic forces or even a combination of these three. Phototropism is what causes the primary shoots to maintain an upright growth. Reaction wood comes secondarily to correct any asymmetries. Despite the differences between gymnosperms and angiosperms, trees in general have the ability to fix their "posture" when external forces are causing them to "deviate". [4]

Another idea is that the leaning is an unavoidable result of biophysical constraints of tall trees, which cannot support a straight, tall and heavy body. There is also a final notion that this behavior is not another adaptive mechanism, but the trees just grow that way. [4]

No matter what the answer is, one thing is for sure, scientist need to look deeper into the matter. Maybe these trees are hiding clues on obscure mechanisms plants use to respond to environmental cues. [4]

What do you think?

I guess these trees just know something we're missing. Maybe there is some hidden treasure in the equator and the trees are trying to show us where to dig. Or maybe there is a tribe lying underground somewhere near the equator. Or maybe, maybe a great deity rests in the middle of the earth and the trees are just paying their respects to it by leaning their heads.