Tree Life, Sickness, and Death—Part 4

As I wrote earlier, trees coordinate their production of seeds. They literally plan a year ahead, so they all reproduce at the same time, in order for them to mix genes. Because of this, same species of trees are far more genetically variable than animals.

Each tree in a forest grows unequally—due to the luck of location. Every individual receives different amounts of water, light, and nutrients. Unable to move to a more advantageous location, a tree does its best where its seed happened to fall. Because of the inequality of location as well as robustness of trees, they cooperate with one another, and strive to equalize their differences. They literally protect each other.

A tree's roots are like its brain. Its experiences and memories are stored in its roots. Roots transmit chemical and electrical signals to the above-ground tree body—very much brain-like. As roots wend their way through the soil, they alter their course—depending on what they encounter; whether it be obstacles like rocks and other plants’ roots, or rich, moist soil. Is this behavior not a type of intelligence?

For a few hundred miles inland from the ocean, moisture is supplied by the ocean's water vapor. Farther inland, however, another mechanism takes over—one provided by trees. The first deserts tend to occur at this distance from the shore, unless trees pull moisture from the ground, transpire it into the air, and create clouds and rain. This is exactly the mechanism of the rain forest. That's why, when large tracts of tropical trees are cut, the area will dry out—leading to savannas and even deserts.

Our skin provides us many crucial functions: it (1) holds in fluids, (2) keeps our organs inside, (3) blocks pathogens, (4) provides tactile sensations, (5) allows us to grow, and (6) sheds. Bark is a tree's skin—it provides the same functions. As a tree ages, its bark grows increasingly wrinkled, as does our skin. Older trees experience a thinning of their crown—just as our hair thins. Their growth slows and they become more spread out; the tree’s bark cracks and allows disease and damaging fungus to invade. It's on its way to death.

A sick tree may put out suckers at its base, while a healthy tree grows primarily at the top. Low leaves on suckers cannot get enough light, and so produce less sugar and nutrients. Saplings from recent seedlings will try to outcompete the older tree’s suckers.

Many other threats imperil trees. Besides the processes of aging bark splitting and allowing various invasions, many alternative kinds of bark damage may occur—from fire, lightning, and due to various animals. The bark assaults open the way for insects, harmful fungi, bacteria, and viruses to invade—just as what happens when we get a cut in our skin. Storms fell many trees. Last and worst: human logging and pollution are major existential threats. It is a testament to the hardiness and resilience of trees, that more death doesn't occur.