Some people deliberately carve on trees.  Carve their name.  Carve their girlfriend’s name.  Carve the name of their college on the bark of a tree (which tells us that even college ‘educated’ people carve on trees).  "Why would they do such a thing?  How can people become so insensitive to this living thing they’re carving on?”

Man has so separated himself from nature, from the things of nature, that he has no qualms about carving on living trees, shooting down one of the few remaining condors, or cutting down entire forests for that matter.  But at what cost to himself, to his fellow?

People go to the drugstore and buy something for a cold, or to help them with pain.  Yet they haven’t a clue where the cold meds or pain relievers come from.  For example, aspirin comes from the bark of a willow tree.  Those who use aspirin should certainly have some desire to see these trees survive - if for no other reason than pure self-interest!  

Bark as Armor

The ancient knights went into battle girded with armor, metal armor.  The first purpose of a knight’s armor was protection against the violent aspects of his lifestyle.  The same might be said for a tree’s bark.  It surely acts as a protection against invasion from outside dangers.  Insects and weather and man are a tree’s three worst enemies.  Yet the bark on a tree helps it survive against all of them.

A tree’s bark is made up of layers of cells, some living, some dead.  Its outer layer, the one we see, is dead cells that become filled with a corklike substance - and air.  The inner layer, called phloem (flo’em) contains living cells that transport food (sucrose: sugar) - made through the photosynthesis process generated by the leaves - to other parts of the tree.

What’s interesting to us is that when these inner cells die (they only live a short time), they move outward and become part of the outer bark.  That outer bark, much like the knight’s armor, serves as a waterproof overcoat.  Not against the weather, per se, but to prevent loss of water from the inside of the tree - through evaporation.  

That outside layer also becomes a barrier to keep out insects and the diseases they may carry.  And, of course, the outer bark insulates the tree from drastic temperature changes.  If you visit the giant redwoods in Northern California, you’ll see many trees that have endured not one or two, but dozens of lightning strikes over the centuries of their lives.  Dark burns abound, yet they go on living.  Thanks to the fire protection encoded into their bark.

Notice in the few pictures we provide in this post how the bark thickness varies from tree specie to tree specie.  The bark on a few of the giant sequoias in the Sierra Nevada Mountains is 24 inches thick.  While on some other trees it’s as thin as a few sheets of stacked paper.

What Causes the Bark Pattern?

As a tree grows by adding a new sapwood layer, the outer bark gets too tight, which causes it to split and crack.  This growth action is what produces the bark pattern for each specie.  These patterns are distinct enough that most trees can be identified by them.

Why We Need Tree Bark

Self-interest?  There's an entire economy produced from tree bark.  Dyes, cork (you don’t have to cut down a tree to obtain the cork), cinnamon, quinine, aspirin, tannin (used to tan leather), and even laxatives.   Bark is sold as a soil mulch, and it’s used as a fuel source in many parts of the world.   Of interest, high-grade cork is not produced until a tree is at least 50-years old.  So when a cork-producing tree is cut down, simply replanting another greatly effects the economy of that area.

An oil in the bark of an evergreen tree native to Sri Lanka produces the spicy cinnamon flavor many people love.  Powdered cinnamon is simply ground bark from these trees.

Teach Your Children to Appreciate Tree Bark

Take some modeling clay with you the next time you visit tree-bearing wilderness.  Over a small area, press the clay against a tree's trunk.  Press it in just enough to capture the impression of the pattern of that particular specie.  Your child will never forget this experience.  If you don’t know the specie, together you can find it - either online or at the library.

If you want to create something more permanent, pour Plaster of Paris into the pattern.  The child can then carve into the Plaster of Paris the name of the tree, the date, etc.

If this doesn’t appeal to you, bring along a few pieces of white paper and make rubbings of the bark patterns.  Rub over the paper with the side of a crayon.  A pattern of the bark will appear.  If this still doesn’t get you interested, just take some pics of bark patterns.  The idea is to get your children involved with tree and wilderness conservation early.  The father of author D.H. Lawrence taught him the names of every living thing in the area surrounding the home he grew up in.  Throughout his life, Lawrence had a reverence for the wild places and all the living things inhabiting them.

Above is the General Grant Tree located in the Sequoia National Park in Northern California.  It's the second largest living thing on earth.  The barn owl is peering out of a cottonwood tree commonly found in Portugal.  It's hard to find the serenity we see in this woman's face.  Could it have something to do with sunshine and trees and quiet?  And finally, there are those who hug trees out of sheer gratitude for their existence.