communicate by exchanging sugar. Trees that receive a
surplus of sun and water produce more sugar than they
require, which they share with other trees that have poorer
growing conditions. This chemical communication allows
one tree to direct energy to a nearby tree that is stressed, in
turn benefiting the ecosystem of the entire forest. He also
learned trees communicate by releasing chemical signals
into the air when they sense the presence of invasive insects
or fungal invaders. This alerts other trees to prepare their
defenses.
When Wohlleben visited private forests in Germany and
Switzerland, the thick, old trees made a deep impression on
him. Given what he learned there, he wanted to institute
changes in the management of the Eifel forest. Eventually,
the forest’s municipal owners agreed to try his methods and
terminated their contract with the state forestry agency. He
brought in horses to replace heavy logging machinery and
eliminated insecticides, allowing the woods to grow wilder.
Within two years the Eifel forest went from loss to profit by
discarding expensive machinery and chemicals.
In his book, Wohlleben states that trees have the capacity
to learn. If a tree uses too much of its stored water, it will
ration its future water use. He also thinks that trees have
a sense of time. They know when to grow leaves in the
spring and when to drop leaves in the fall. They can sense
temperature and day length. They won’t sprout leaves until
the days are long enough. Scientists are not sure how trees
measure daylight, but they think it is a function of the
dormant buds. However, to sense time, trees need memory.
Without memory, they would not be able to count warm
spells or compare length. Swedish researchers studied a
small spruce trunk and were amazed to discover its roots
were 9,550 years old. Wohlleben posited this is where tree
equivalent of a brain would be located.
So what does this have to do with our live oaks? Without
coastal forests, inland regions would dry out. In ancient times
the massive canopies of ancient live oak forests took in water
vapor that blew in from the ocean. They then transferred
that water deeper into inland regions, forest by forest. South
Carolina’s live oak forests were destroyed when they were
harvested for shipbuilding or clear-cut for cotton fields.
Our coastal live oak forests are gone but individual giants,
like Angel Oak, give us an idea of how incredibly beautiful
these forests must have been. Forests where parent oak trees
sheltered their children, feeding them through their roots.
Just imagine what Angel Oak would look like if its children
and grandchildren surrounded it. The expression and act
of knocking on wood for luck comes from people knocking
on trees to thank the spirit of the tree for granting them a
favor. NK
Photo by Ann Gridley
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