Thursday, March 23, 2017
WOOD WIDE WEBS
Blue Ridge Forest, Blue Ridge Parkway, NC
Forest Floor, Blue Ridge Parkway, NC
Enchanted forests are a thing of fairy tales where trees like the legendary Ents walk and talk and live in community—or are they? I’ve always enjoyed watching videos of graceful long legged and long necked giraffes on the African savannah browsing for food among the tree top canopies of umbrella thorn acacias. But I missed the subtle movement of these giraffes as they suddenly stopped eating and moved about 100 yards away to another acacia. Peter Wohlleben writes in his New York Times bestseller, The Hidden Life of Trees, that scientists recently discovered that the acacia trees immediately had begun to pump toxic substances into their leaves to ward off the herbivores. They also began to give off a warning gas of ethylene to signal neighboring acacias of the danger.
When an insect attacks beeches, spruce, and oaks they register pain as soon as the creatures begin to eat their leaves. The leaf tissue immediately begins to send out very slow electrical signals so that within hours defensive materials reach the leaves. The trees even release pheromones to summon beneficial predators. Surprisingly, both chemical and electrical signals are sent through fungal networks around tree roots. Individual tree roots extend more than twice the spread of the crown and become intermingled among other tree roots forming a “wood wide web”. There is an Oregon underground fungus colony known as mycelium that is estimated to be over 2,400 years old and extends for 2,000 acres. These signals are then passed along to other neighbors in the forest. Scientists have found that networked trees even share nutrients with each other if one of the trees is struggling and they will even keep a cut stump on life support for years, especially if the stump belonged to a harvested mother tree that had nourished the younger trees which are now thriving in the opened space.
Wohlleben writes that “A tree is not a forest. On its own, a tree cannot establish a consistent local climate. It is at the mercy of wind and weather. But together, many trees create an ecosystem that moderates extremes of heat and cold, stores a great deal of water, and generates a great deal of humidity. And in this protected environment, trees can live to be very old.” He noted that a pair of trees that grow up alongside one another allowing each partner to share life-giving light and not infringing with dense branches in each other’s space have a sort of symbiotic relationship. And they can become so tightly interconnected at the roots that sometimes they even die together.
Dr. Suzanne Simard coined the term “wood wide web” after researching and writing her doctoral paper. She was studying the mystery of the decline of Douglas firs in Vancouver plantations where paper birches had been weeded out. After injecting stable and radioactive isotopes in a forest with both fir and beeches, she found that they were actively exchanging photosynthetic carbon in a mutually beneficial network! Each took different turns as “mother” depending on the season in a synergistic relationship similar to a caring human social network.
Isn’t it amazing that we humans can still learn so much for our own survival by observing the awesome behavior of the created nature around us?
The best time to plant a tree is twenty years ago. The next best time is today. I've finally realized that also applies to a lot of other things like going to the gym. And the best definition of a legacy is planting a tree whose shade you will never sit under.