Returning to Trees
By: Belatrix Bean
Tags: Ecology, Evolution, Trees, Plant Science, Science

Returning to Trees

A wander through the science and symbolism of majestic oaks, as we search for a way home to forests.

Along the country lane, a solitary row of oak trees arches towards the road as if to offer a safe passage to all who pass. The winter branches are bare and the rain-soaked wood is black against the grey sky. These oaks are exposed to the full force of storms, climate and petrol fumes. They also suffer the runoff from pesticides used on nearby farms.

As I pass the lane I feel a twinge of regret.

In the Devon landscape these isolated oaks appear not as Tolkien’s Ents, but as bronchial silhouettes. Perhaps like you, I have my own perspective on trees, familiar with those in my local environment. I associate them with breath, oxygen and life.

I now also recognise them as masterpieces of evolution.

Oak evolution had been taking place for at least 50 million years before our first apelike ancestors began walking upright on two legs. They radiated and expanded across Europe, North America and East Asia, leaving large numbers of co-occurring species in their wake, all with the potential to hybridise and exchange genes that would prove useful as they continued to colonise new territory.

As the last glacial period thawed, birch and pine, hazel, elm, oak and alder spread across all of Britain, forming an expansive wild wood. From the Neolithic age deforestation began in earnest when half of all forests were cleared for agriculture. Each succeeding era saw vast depletions of trees for timber and pasture land which continues today.

Not so long ago we hunted, cooked, feasted, and created new life under the leafy boughs and canopies of trees.

If a helicopter could fly over Britain just a thousand years ago the land would have looked like a mosaic of dense canopy and open ground. You would see ‘thin blue spirals of smoke rising here and there’ from the cottages; the oaks thriving near the outskirts where they could gain sufficient light.

Dwelling in the forests, we forged a sympathetic connection to oaks as we lived as part of a mutual ecosystem. As we started to migrate into the swelling farms and villages we brought with us the folkloric oak beliefs that for so long enabled us to live and cooperate as a species in their world.

To fell an old oak tree was almost unthinkable: medieval woodcutters feared the dreadful ‘shrieks and groans’ that came from the tree as it was about to fall. They were warned off by superstitions that misfortune would befall those who cut down ancient oak groves.

Destroying something so old and deep-rooted has never been taken lightly.

As the forest shared ever more of its resources with us, we grew confident in despoiling its ecosystem until we abandoned it for good. Now we can no longer hear the oak’s screams we have fewer qualms about cutting it down.

As we hurtle into a new planetary age of mass extinction, the oak trees reveal what it means to thrive as a species. In doing so they hold up a mirror to the human race, perhaps reflecting an uncomfortable truth.

We formed an emotional attachment to oaks, more than with any other tree. For thousands of years oaks stood as symbols of stoicism, strength and the wisdom of old age. This much is evident in the many spoken aphorisms that draw on their robustness and resilience. You could even say we lavish them with too much human compassion.

As far as trees go there isn’t anything especially outstanding about oaks. Their immune systems are strong, having evolved to ‘neutralise’ many of their natural enemies: viruses, bacteria, insects and fungi among other pathogens. Being resistant to disease and rot also contributes to the high value of oak wood as a building material.

The towns and villages emerged from postglacial forests and were constructed with oak timber. In the houses, dining tables, bookcases and floorboards were all made from oak: the wood being preferred for its durability, versatility and appearance.

As the timber ages it’s said to become stronger, but this is barely an aphorism. Rather, it becomes more beautiful as it acquires an antique charm.

Contrary to belief, oaks are not the longest surviving of all trees or the most robust. A bristlecone pine claims the record at around 4,867 years. Old Tjikko, a spruce in Sweden, is an estimated 9,550 years old!

The oldest oak in Britain is the Bowthorpe Oak at around 1000 years — an infant in comparison. Ebony wood is stronger than oak, ranking among various hardwoods in the African and Indian continents. And like us, oaks are also vulnerable to acute population decline by new and foreign viruses.

Yet oak trees carry a potent symbolic status that informs our understanding and beliefs about them. For some plant scientists our romantic ideas about oaks, and trees in general, could have unintended ecological consequences.

As the world wakes up to the climate emergency, rising numbers of people are taking a stance against the ongoing deforestation rapidly wiping out millions of species.

Evolutionary scientist, Dr. Thibault Leroy, and his colleagues, recently published an article on oak symbolism in the light of genomics. While pleased to observe a growing popular interest in trees and the protection of forests, Leroy has voiced his concern about a growing movement to resist felling any trees.

Leroy’s argument is that forests need to be sensibly managed so we can start replacing plastic products (made with fossil fuels) with sustainable wood-based solutions. He questions if an emergence of anthropomorphic nature writing might be fuelling romanticised ideas of trees that could compromise our ability to effectively solve the climate crisis.

One bestselling work has made quite a stir in the scientific community. In The Hidden Life of Trees, Peter Wohlleben presents the case that trees are ‘feeling and communicating’ creatures that live together like human families. In the forests, tree parents nurture their offspring and provide nutrients to ‘sick and struggling’ trees, comprising a social system.

Wohlleben’s anthropomorphic narrative is largely inspired by scientific findings that trees are connected to sprawling mycorrhizal networks that drive acts of reciprocity and mutual support. These discoveries were made by Suzanne Simard, Professor of Forest Ecology, who in her ground-breaking work also identified ‘mother trees as vital hubs’ performing a variety of functions that place them in the role of forest caregivers to saplings.

This new perspective of plant interdependence looks beyond natural selection as an unintentional chemical process. Instead, it probes the evolutionary mechanisms which engender cooperation, communication and kinship in nature.

Does Simard’s science and Wohlleben’s narrative imply trees in forests are more like human societies than previously thought? Well, there is an important distinction to be made. For humans, social cohesion is a complex emotional experience: something that is carried out intentionally as well as instinctually, and is largely due to our language skills. We know plants communicate through chemical signalling, but do they behave intentionally? Not as far as we know.

Within the plant science community Simard’s research is well-respected. Neither is there any empirical problem in likening human characteristics to trees. They compete and cooperate for survival just as we do — although they do so very differently.

It’s possible we have always ascribed human characteristics to trees, wanting to know them as feeling, communicating, and sentient beings in order to pay them respect — perhaps not to feel so alone — but in doing so we miss an opportunity to tap into something far richer and transformative in the light of modern science.

Oaks are an evolutionary success in terms of diversity and abundance. Dr Andrew Hipp, Senior Scientist in Plant Systematics, describes them as 435 species all working on solving the same problems, over and over in different ways.’ Of all the woody plant genera of North America, oaks have the highest number of species and most biomass. By their sheer diversity and ability to adapt, exchange genes, and migrate rapidly, they have come to dominate in a wide range of forest types. And, remarkably, they often share the same community: when you find one oak species in a forest, you commonly find at least one other as well.

But to call this a ‘success’ is perhaps to put too much of the human into the trees. They flourish through natural selection, migration, mating with their own kind and others, speciating, going extinct — all of which are natural events.

One can try to understand these processes in relation to the human experience, but even using anthropomorphic language we will struggle to relate to migrating without legs, radiating across continents, cross-pollinating in the wind and speciating over millennia. Like mathematics, understanding trees requires us to comprehend patterns and forces in nature that elude our senses and daily life experiences.

For biologists, using language to accurately describe an oak species is just as elusive. Oaks consist of so many converging characteristics it’s difficult to tell some species apart just by observation. In this sense there’s no such thing as a definitive oak species, but a kaleidoscope of oaks.

Trees aren’t like us at all. They’re not one but 60,000 species.

As humans we take pride in our large brains and talents for science and poetry. Having mastered tools and technology we think of ourselves as supremely successful and destined to last. But consider this: we once inhabited the Earth with other hominid species that shared many of our evolutionary challenges.

And now we are just one.

Alone, we face the problem of imminent extinction from a catastrophic event like the advent of a super virus. The complex and subtle diversity of tree evolution stands in stark contrast to our own.

In a very short time, human civilisation forged an alternative reality in conflict with the natural world. Deep in our conurbations we are a beleaguered species, addicted to gas, coal and oil. It seems the more efficient we become the more we compromise our natural environment.

Our vision is narrowed by an obsession with clock time. As a species in a hurry, we travel in the most linear way to arrive sooner rather than later.

When one thousand ancient woodlands are to be cleared to make way for the UK’s new High-Speed railway, bypassing the old oaks isn’t workable. A route which bends and detours like a snaking woodland stream adds several unbearable minutes onto the journey.

Our need to get places faster has presented us with a dilemma: the more efficiently we use the Earth’s resources the cheaper they become and the more we rely on them. Consumption levels continue to rise, as does climate chaos, creating a rebound effect.

Hominids have been failing to arrive at win-win situations with our own and other species.

As the last survivor of our kind we remain inescapably bound to forests, just as the shore is bound to the ocean. Trees were once everything to us: our keepers providing food and fuel and the timber we used to build ships, housing and so much more. Now that we know our reliance on fossil fuels is leading to catastrophe, we are searching for a way to return to trees.

If the life of oaks can teach us anything, it’s how we overthink the problem of survival. Shall we privatise this or that service so the strong can prosper? Or should everyone pay into a system that distributes the benefits evenly, ensuring the weak can also thrive? At every turn we are torn between the choice to either cooperate or compete.

Oak trees do not share our burden of having to make choices. They perform their evolutionary tasks with indifference to their suffering neighbours. As they also pay no attention to the myriad benefits they bestow on the animals and other plants they host.

By way of our mindset, we are locked into a contest with nature for finite resources. But with oaks there are no contradictions: different species live side by side in an understated unity.

The oak simply thrives, and, all things being equal, exists in the complex society of which it forms a magnificent part.

Curious for more? Sources and references for this article can be found here.