Talking Trees

The spring equinox was on the 20th of March, marking the start of astronomical spring, when the days become longer than the nights and the temperature starts to rise. With this comes one of the most striking transformations to the landscape around Loch Sunart. It is the return of foliage to the ancient Atlantic oakwoods on the hillsides that run down to the sea. At first, tiny buds emerge on the branches—small and barely noticeable. But with each longer day, they grow more prominent. By mid-April, the buds burst open, revealing delicate, pale green leaves and by the end of April, the once bare and dormant branches have been replaced by a living canopy of verdant beauty. Seen from above, each tree stands out distinctly, as if they’ve agreed to respect each other’s space. But how is this possible? Could the trees be communicating? I’m always left wondering.

Broccoli - Sàilean nan Cuileag, Sunart

​Well, this canopy of distinct trees, which looks like clusters of broccoli florets, is because of a phenomenon called ‘crown shyness’ where the trees are not so much talking to each other, but more sensing each other’s presence.
 
Scientists think this happens because the trees can detect a specific type of light called far-red light. This light tells them when they are getting too close to their neighbours. When they sense this, they stop growing in that direction, which helps them make the best use of sunlight and ensures they don't compete for light.
 
Another possible reason for crown shyness is physical contact between branches during windy conditions. As the wind moves the branches, they rub against each other, causing small injuries or broken tips. Over time, this repeated friction may prevent further growth in those areas, creating the distinctive gaps between tree crowns.
 
Either way, this intriguing phenomenon underscores how trees, despite their stationary nature, exhibit remarkable sensitivity to themselves and their environment. However, it is thought that trees go beyond this and do in fact communicate with each other in a number of ways.
 
In his bestseller, The Secret Life of Trees, German forester Peter Wohlleben reveals how a gigantic underground fungal network, that he calls the “Internet of the Forest”, enables trees to exchange information. Known scientifically as the mycorrhizal network, it allows trees to exchange nutrients, water, and even chemical signals.
 
At its core are mycorrhizal fungi, which form symbiotic relationships with tree roots. The fungi provide trees with essential nutrients like phosphorus and nitrogen, while trees give the fungi sugars produced through photosynthesis. These fungal threads, called hyphae, spread through the soil, linking different plants and creating a vast, interconnected web.
 
He explains how trees use this network to communicate and support each other. For example, large, older trees, called "Mother Trees," send nutrients to younger or weaker trees. They also use it to release warning signals when under attack by pests or diseases, alerting their neighbours to activate their defences with the result that the health of the forest as a whole is maintained.
 
Another form of communication he describes is the mutual assistance they give each other through their root systems. A tree on the brink of death can be kept alive by a healthy neighbour. The latter shares the nutrients it has transformed through photosynthesis with the ailing tree until it is strong enough to feed itself. Similarly, young trees growing in the shade of larger ones often do not get enough light to photosynthesise their nutrients. So, in these cases, the larger, more established trees feed them via the vast, branching fungal network beneath the ground on which they sit.
 
Trees also communicate through the air using something called phytoncides. They are natural chemicals produced by plants, especially trees, to defend against harmful microorganisms and are released into the air around the trees. They are also beneficial to us and when we walk through the woodland, we unknowingly breathe them in, boosting our immune system and overall health. So, the next time you are wandering through trees, remember – they’re constantly talking to each other, supporting one another, and even benefiting us in the process.

Spring Woodland - Loch Sunart, Resipole, Sunart