The Hidden Life of Trees: What They Feel, How They Communicate — Discoveries from a Secret World

by Peter Wohlleben

The electrical impulses that pass through the roots of trees, for example, move at the slow rate of one third of an inch per second.

When you know that trees experience pain and have memories and that tree parents live together with their children, then you can no longer just chop them down and disrupt their lives with large machines.

forests are superorganisms with interconnections much like ant colonies.

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.

Trees, it turns out, have a completely different way of communicating: they use scent.

The giraffes there were feeding on umbrella thorn acacias, and the trees didn’t like this one bit. It took the acacias mere minutes to start pumping toxic substances into their leaves to rid themselves of the large herbivores. The giraffes got the message and moved on to other trees in the vicinity.

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 the forewarned trees also pumped toxins into their leaves to prepare themselves.

The saliva of each species is different, and trees can match the saliva to the insect. Indeed, the match can be so precise that trees can release pheromones that summon specific beneficial predators.

Scientists have determined that slow growth when the tree is young is a prerequisite if a tree is to live to a ripe old age.

In Central Europe, there are no longer any true old-growth forests. The largest extensive stand of trees is between two hundred and three hundred years old.

Carbon 14 is a radioactive carbon that continuously forms in the atmosphere and then gradually decays. This means that the ratio of carbon 14 to other carbon in the atmosphere is always the same. Once carbon 14 is incorporated into inactive biomasses, for instance wood, the process of decay continues unabated, but no new radioactive carbon is accumulated. The lower the amount of radioactive carbon it contains, the older the tissue must be.

Conifers give off terpenes, substances originally intended as a defense against illness and pests.

to find out whether this is indeed groundwater or just surface water left over from a heavy shower, reach for your thermometer. Less than 48 degrees Fahrenheit? Then it is indeed a spring.

spruce don’t like having wet feet

It takes a beaver one night to bring down a 3-to-4-inch-thick tree. Larger trees are felled over the course of multiple work shifts. What the beaver is after are twigs and small branches, which it uses for food. It stockpiles enormous quantities in its lodge to last the winter, and as the years pass, the lodge grows by many yards. The branches also camouflage the entrances to the tunnels that lead into the lodge. As an added security feature, the beaver builds these entrances underwater so that predators can’t get in. The rest of the living space is above water and therefore dry.

Although beavers damage the forest around them, they exert a positive influence overall by regulating water supplies. And while they’re at it, they provide habitat for species adapted to large areas of standing water.

These rust-red birds with gray heads normally sing a song whose rhythm ornithologists like to transcribe as “chip chip chip chooee chooee cheeoo.” But you’ll hear that song only on a fine day. If it looks like rain, the song changes to a loud “run run run run run.”