“I am vertical/But I would rather be horizontal,” wrote Sylvia Plath, meditating on the consequences of a treelike existence. A team of researchers from the Vienna University of Technology recently announced another perspective on arboreal repose. Using sophisticated laser scanners they created images of trees during the night, when their metabolic processes slow down, and found that their branches had perceptibly drooped. They had “gone to sleep”, in the team’s words.

It is hardly a revelation: if your fluid pressure is reduced, you sag. What’s more interesting is the researchers’ language and their resorting to the ancient metaphor of “sleep”. Finding analogies between the physical forms and processes of trees and our own vertical life seems to be compulsive, a habit that goes back through Plath to the Romantic poets and beyond. We anthropomorphise them in a directly corporeal way. We talk of limbs and crowns and trunks. When a tree is felled we see a body, severed from its earthly roots and killed. Our empathy is understandable, and helps the world seem a more joined-up place, but it does a huge and damaging injustice to the tree world.

Vegetal existence is defined by immobility. Plants are rooted to the spot, which means they cannot escape predators or pursue sexual partners. To compensate they have evolved a modular structure and a range of senses and communication channels which far exceeds our own, and which includes sensitivity to magnetism, static electricity, low frequency sound waves and ultraviolet light. New understanding of plants’ abilities (and intelligence: they can learn, remember and change their behaviour as a result) means that they are beginning to be afforded the status of autonomous beings.

Plants were regarded as no more than the furniture of the planet — useful, decorative, even indispensable; but essentially passive. Their growing existential stature means that we will have to rethink notions of “the natural order”.

Even their reproductive strategies suggest inventiveness and opportunism, not rigid genetic scripts. A modular structure means plants have no irreplaceable organs and are usually able to regenerate even when nine-tenths of their living tissue has been destroyed. In the months after the Great Storm of October 1987, while doomsayers were announcing the ruination of the landscapes of southern England, I found a legion of trees unfazed by horizontality. Oaks and hornbeams were sending up new shoots all along their prostrate “bodies”; black poplars and beeches had aspiring new trunks climbing out of their upturned root-plates.

A few years ago I went to see what is probably the oldest tree in Europe, the Great Yew at Fortingall in Perthshire. Its previous immense size (20 people could have joined hands around it in the 18th century) and likely age (between 4,000 and 5,000 years) mean that it suffered in the past from souvenir hunters. The response of the authorities has been to put the hapless veteran in an iron cage, and to saw its branches back. This gives it the look of a specimen in a freak show, but has also emasculated it.

Last year, the Fortingall yew, a male tree, called on some ancient genes and transitioned, producing two female berries in the autumn.

We tend, trapped perhaps in the values of our own time and species, to regard trees as individuals. But they are inextricably social beings. Under the ground all trees are supported by symbiotic fungal partners. The tree supplies the fungus with sugars, the fungus extracts minerals from the soil and filters them into the trees’ roots. The complexity of this networking is only now being uncovered. It looks as if the fungal network connects all the trees in a wood regardless of species.

Using radioactive carbon markers, scientists have found that the fungi (or some distributed group intelligence) transfer food from evergreens to deciduous species in the winter and vice versa in the summer. The fungal network also acts as a conduit for sharing information about water availability and attacks by predatory insects, to the extent that it has been nicknamed “the wood-wide-web”.

A similar chemical chattering (it is hard not to use human analogies) happens above ground. When the leaves of trees such as oaks and willows are attacked by insects, they are prompted to produce more bitter-tasting tannins. More remarkably, they also produce airborne pheromones which encourage the leaves on other parts of the tree to up their tannin before they too are attacked. Over the great stretches of evolutionary time, other species have learnt to hack these vaporous signals, so that in a seeming contradiction of selfish-gene theory, many individuals of several species benefit from the original tree’s defence mechanism.

I cannot see how we can hope to find a place for ourselves in the Earth’s web of life without using the allusive power of our language to explore trees’ dialects of form and pattern and chemical messaging. But we must not smother their gift to us of different models of being alive. As Samuel Coleridge, great lover of plants, wrote that “everything has a life of its own, and that we are all One Life.”