July 12, 2023
By Michael Collins, Teravana
If we leave trees alone, they will take care of themselves. Trees make seeds, which then grow into other trees. When deciduous maples and oaks drop their seeds to the ground, some land in a place where they are capable of growing. All coniferous trees have cones that house seeds. When they fall to the ground, they can be moved to new destinations by animals, heavy rains and snow melt, or by birds.
Once grown, the trunk is the engine that protects the tree and passes food to the rest of the tree. The growing process that eventually results in leaf buds at the end of branches starts in the cambium cell layer of the trunk. The center-most layer is called heartwood, the central, pillar, providing support for the crown. It is here where we can trace rings and find out how old a tree is.
Leaves make food for the tree, the main place for photosynthesis. The shape and thickness and color of leaves are adapted to the environment, helping plant species maximize their chances for survival. For example, leaves or trees in the Amazon often have large surface areas, but plants in the desert or especially cold places often have a small surface area, reducing moisture loss. According to the National Park Service, “small leaves mean less evaporative surface per leaf.”
Looking at these adaptation skills, all signs point to trees having minds of their own, making decisions, and thwarting danger. It is not hard to believe trees communicate, protecting one another, a unified force standing up in the forest.
Trees living with one another have far longer lives than those in isolation. According to Peter Wohlleben and his book The Hidden Life of Trees, “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.” One way to explain this concept of compatibility is to look up at the crowns of a grove of trees and notice how their outer branches do not infringe on one another’s space.
Another quiet phenomenon is how trees protect one another from threats. The Hidden Life of Trees, tells the story of giraffes in the African Savannah feeding on acacias. According to Wohlleben, “The acacia trees that were being eaten gave off a warning gas (specifically ethylene) that signaled to neighboring trees of the same species that a crisis was at hand. Right away all forewarned trees also pumped toxins into their leaves to prepare themselves.” As a result, the giraffes moved on and found other places to feed.
The wonders of how trees think together go on, especially when we talk about interconnected root systems and how thinking funghi in the soil can send messages to the surrounding forest.
Trees have been around for hundreds of millions of years and have probably always had many of these skills. But it is also fair that some talents of these trees are adaptive and have evolved.
What we have discovered is that the more we explore, the more we encounter scientifically proven instances of trees collaborating or exhibiting abilities we typically wouldn’t associate with a tree trunk, its branches, and leaves.
