In a nutshell, trees, like all plants, grow upward reaching for the light of the sun because they're hungry. They all collect sun energy, CO2 and moisture to combine and convert into glucose to provide themselves with the food energy they need to store to stay alive. It's called photosynthesis.I'm an engineer---not a biologist. But I was looking at a forest of tall pine trees and got to wondering why, exactly, do trees grow upwards?
Is it because they are the attracted to the sun?
Or repulsed by gravity?
How do they even know which way "up" is?
Would a tree growing on a spaceship (absent gravity) under artificial light grow towards the light?
And what, internally, makes them grow towards the sun, if that is the driving factor?
The first link posted here explains how that works.
The second link is about the zero gravity experiments that have been done with growing plants on the space station using artificial lights. If a space station was a lot bigger than the existing space station the same thing could be done with trees.
What Provides Electrons For the Light Reactions?
The sun is the main source of energy for almost every living thing on Earth. It gives a plant the light energy it needs to photosynthesize, which converts that light energy into a storable form (glucose) and keeps plants alive. A by-product of photosynthesis is the oxygen all animals need to survive.
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