Please sign in to participate in this lecture discussion.

Resetting Your Password?

Start Learning Now

Our free lessons will get you started (Adobe Flash® required).
Get immediate access to our entire library.

Membership Overview

  • Available 24/7. Unlimited Access to Our Entire Library.
  • Search and jump to exactly what you want to learn.
  • *Ask questions and get answers from the community and our teachers!
  • Practice questions with step-by-step solutions.
  • Download lecture slides for taking notes.
  • Track your course viewing progress.
  • Accessible anytime, anywhere with our Android and iOS apps.

An incredible phenomenon “Crown Shyness”

“Crown Shyness”is a natural phenomenon in some species of trees, where the upper branches of the forest avoid touching each other. The visual effect is impressive, as it creates clearly defined boundaries, similar to cracks or rivers in the sky, when viewed from below.

Some believe that this is done to reduce the spread of harmful insects. Others believe that trees are trying to protect each other’s branches from cracking and breaking in the wind, and it has also been suggested that “crown shyness” happens so that trees can optimize light exposure to maximize the photosynthesis process done by the leaves.


Get full access to’s entire library of courses.