RIVER TREES
What if we started looking at our planet's rivers as trees?
Just think about it: a river and its catchment area, a vast network of tributaries, are just like a tree, a beautiful and complex ramification, a hierarchical arborescence filled with a vital flow that has its ups and downs throughout the year according to the seasons.
Taking this a step further, the river, like the tree, can fall ill and bear fruit on its branches: cities, while its lakes and ponds are like outgrowths on the surface of the wood. The river, like the tree, blends environments, makes them communicate: subterranean, wooded and above-ground environments for the tree, that are echoed in the salty and brackish coastal waters, the plains, valleys and mountains that the rivers link.
Welcome to this series of botanically inspired maps of some of our planet's great rivers, all of them oriented in such a way as to evoke the silhouette of a vegetal organism. Through these maps, each of the rivers takes on a new appearance, organic and shrubby, like trees of various species and shapes that have flourished in an environment sometimes windy, sometimes wet... Expressed in this way, these river-trees reach for the mountains and ice at the top of their peaks, while their estuaries, their invisible roots, plunge deep into the world's seas and oceans.
Data: HYDROSHEDS
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THE LOIRE
Let's begin our botanical and hydrological adventure in the forest of these great river-trees with THE great French river par excellence, a treasure trove of French history and geography: the Loire!
It is the country's last great and relatively wild river, stretching for almost 1,000 kilometres across the country, with its source located in the Ardèche, just a few dozen kilometres from the Rhône.
And yet the branches and trunk of this long tree cross a great deal of places on their way to the vast Atlantic Ocean! Here are some of them, in order: Languedoc, Lyonnais, Nivernais, Orléanais, Touraine, Anjou and finally Upper Brittany, with its sedimentary soils, salt marshes and great estuary. So far from the rugged and ancient mountains of the Massif Central, Brittany is nonetheless united by the living, moving blue thread that runs so admirably through our country. Let's take a look at this tree.
To begin with, its history is interesting and somewhat mysterious: scientists who have carefully examined its branches, and perhaps even inspected its rings, have put forward hypotheses evoking a distant past when the Loire, far from following the course we know today, branched off towards the course of the Seine to flow into the English Channel. If this hypothesis is confirmed, it would have been known as the Loire séquanienne! A fine example of the past life of a river which, even today, remains alive, dynamic, dancing, one might even say, so much so that the sequence of lateral movements of its course, forming loops, lines, bulges, interlacing and hollows, evokes a perfectly mastered choreography.
Just as a tree changes with the seasons, growing, flowering, expanding, shedding its leaves, shrinking and twisting under the stresses of life, the course of the Loire grows and deforms with each winter, only to become dormant in summer, when it shrinks and a new course sometimes appears.
So where does the Loire River begin? Its course begins somewhere in the middle of our country, in the south of the Massif Central, in the Ardèche, where the first branches of the summit come to life in the form of small mountain streams that soon become fast-flowing rivers cutting through the steep landscape. The rivers come together and this mighty river swells and takes shape until it can ‘carry a boat’ around Saint-Étienne. Once past Roanne, the Loire moderates, its course becomes less steep and it gradually enters the second part of its course, the middle Loire, as if it were mellowing with age.
It is in this part of the tree, at mid-height, in this branchage, that magnificent châteaux and splendid historic towns such as Blois, Orléans and Tours have flourished, so many histories, kingdoms, trade and works of art that have spread their inspiring pollen far into the forest...
As you continue to work your way downwards, you start to reach the bottom of the tree where the trunk thickens and the plant structure becomes more complex: this is where you find the ‘boires’, the dead branches of the river, like the dead branches of a tree, except that those of the Loire swell with sap in winter when the water level rises and the water invades these former silted-up branches of the river. This is the lower Loire, where we find Angers and Nantes, the last major city on the course of the river proper and which, together with Saint-Nazaire, best embodies the industrial history of the river, a history turned towards the ocean, a history, among other things, of slavery which unfortunately caused a lot of sap to flow from other trees in different latitudes. There were also exchanges of exotic goods, fabrics and industrial products that required the river, its course and its banks to be developed for the needs of navigation. These exchanges have largely disappeared or moved further down to the roots, but the marks left by this past life on the bark of the tree are still very visible.
For each botanical portrait developed in the series, I will suggest a (very real) tree species in the image of our river, to form a pretty botanical name. So, if the Loire were a tree, it would probably be an old oak. A pedunculate oak. The Loire and oaks are quiet creatures, evolving slowly and thriving in a fairly humid climate. The oak is a tree of noble essence, both an ambassador of ancient, wooded Europe, the Europe before humans, and the tree of shipbuilding, barrels of Loire wine, cathedrals and châteaux scattered along the branches of the river...
And so ends the portrait of the first River-Tree that I share with you: the Loire Oak, Quercus Robur Ligeris.
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THE AMAZON RIVER
This is the second botanical portrait of a river in our ‘River Trees’ series.
After the Loire, the Amazon river. One is the largest river in France, the other simply the largest in the world. Two Goliaths in different categories. In the case of the Amazon, it's impossible not to begin its portrait without mentioning its dimensions, which make this river unequalled, unique, colossal, gigantic.
Words that quickly become superlatives for the Amazon are soon running out when it comes to describing this river. So where to start? Its flow alone represents 1/5 of the world's river flow. Seen otherwise, it is greater than that of the next 5 most powerful rivers combined. To put it in figures, its flow is 209,000 cubic metres per second in the estuary, which is itself 60 km wide. Coming back to the Loire, its maximum flow barely touches 1,000 cubic metres per second at its mouth. So the Amazon is 210 Loires. In the second half of its course, this South American river is so wide (10 km on average) that if you stand on its banks, you can only see the other side on a clear day. The nickname given to the river by the locals, ‘river-sea’, takes on its full meaning. The last figure is too fascinating to ignore, although a little enigmatic: the Strahler index for the river is twelve. It's unheard of.
I hope that after this short presentation, you can take the measure of the immensity of this river as I have.
THE RHÔNE
For this portrait of ‘Rivières Arborescentes’, the Amazon River appears to be a natural choice, as the river is inseparable from the Amazon, the largest forest in the world, which covers its watershed, also the largest in the world, with over 6 million square kilometres (12 times the size of France). This great Amazon tree is home to 30% of the world's tropical tree species, 3 million animal species and a tree whose branches and leaves are watered by the famous ‘atmospheric rivers’, air currents carrying the water evaporated by the trees, which falls back as rain on the same forest, swelling the rivers or watering the trees. This great Amazon tree, fertilised from the air by sand from the Sahara on the other side of the Atlantic, is an organism suffering from declining health. Every year, we humans strip it of millions of hectares of its green foliage which, unlike the trees we know, will not grow back the following spring. We are destroying the most precious and important forest in the world to feed our cattle.
This river with its complex ecology is home to forms of life that defy the imagination, and its summit lies some 6,000 metres above sea level, between several tributary basins, in the cold Andes mountains. It then swells with the waters of Ecuador, Colombia, Peru, Bolivia, Venezuela and, of course, Brazil. Among the 1,000 rivers that make up the Amazon tree are powerful ones like the Rio Negro, ‘black river’ because of the colour of the organic matter, humus and iron it carries. Other rivers are white, such as the Rio Branco and the Rio Caquetà, a hue due to the alluvium and sediment that the river tirelessly tears from the mountains.
This concludes the portrait of the second river-tree I'm sharing with you: the Amazon mangrove, Avicennia Amazonia.
It is following this mingling of waters, which flow, run, sometimes dozens of kilometres together without mixing, that the Amazon takes shape and forms the trunk of this great tree. Further down, the trunk takes root in a vast delta, a world of coastal towns and villages on stilts, threatened by rising sea levels as everywhere else: the salt water rises ever further into their brackish world and the huts collapse without warning.
It is in this part of the river that I find the most poetic phenomenon: the Amazon plume. The freshwater surges into the sea in such quantities that it forms a large mass of water (a trace or plume in satellite images) that is carried north-westwards by the force of the ocean currents. This is how the deepest roots of the Amazon tree extend to... the West Indies! The seawater of the West Indies is influenced by the river and the effluent it discharges into the ocean: sediment or pollution.
Before I bore you any further, let's conclude: if the Amazon were a river, it would certainly be a mangrove. An emblematic tree of tropical coasts, it is a major carbon sink and home to many forms of life, and is used to having its feet in the water, just like the river, which regularly floods its surroundings, creating an amphibious world all around it.
The mangrove, with its curious shape and extravagant roots, covers the banks of the river delta - the base of the trunk - and forms mangrove forests, where the immense river concentrates all its strength for the great encounter with the even more immense marine world.
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The Rhône! It's the second biggest river in France, and although it's not as long as the Loire, it's still the biggest in terms of flow and power. The Rhône is a powerful river: just look at it! It's a straight column, just like the people of classical times used to make. The Rhône is a river-tree, like all the others in this series, but it's also a river-civilisation: it was a passageway, a trade route, from the Mediterranean to the North Sea. The vicinity of the river is where the Greek and then Roman presence in present-day France took root. Take a look at this column in the landscape, this tree with a straight, solid, clean and confident look that plunges its roots and flows southwards. If you look at its top, you can also make out its mountainous character, its original nature as a fierce and ferocious glacial torrent, almost untamable, born of a glacier hidden deep in the Alps. Another glacier, the largest in Europe, the Aletsch glacier, also gives it its water and its power. But at what price? The glaciers have been giving too much water to the rivers for decades. The tree is well watered.
These torrents, which flow earlier each year, in spring, and plunge into a hibernating sleep each winter, tumble through rugged mineral landscapes before joining the great Alpine lakes, melancholy remnants of the ice cap that once capped the roof of Europe 20,000 years ago. Lake Geneva, Lake Annecy, Lac du Bourget: places that are popular and widely used by humans today, but ancient and geologically rich... This is where the heart of the river lies.
Gone are the torrents,when the Rhône reaches the plains, but the river loses nothing in terms of power: it is so powerful that we humans harness it along its entire course, from dam to dam: 19 times along its course alone. As it is too powerful to be left free, in 100 years we have artificialised 80% of its course. The Rhône Valley produces a quarter of France's electricity! If the Loire's finest hour was the Renaissance, the Rhône's was the Industrial Revolution, when mills, factories, petrochemical plants and nuclear power stations sprang up like mushrooms along its course.
If the river is a tree, a living organism, we are at best an epiphytic plant (a plant growing on another plant, not in the soil), at worst a parasite. We take from the river. What do we give it?
We like to call this industrious river and its mark on the landscape ‘the Rhone furrow’. Notice this profoundly earthy term, like the furrow formed in the field by the farmer's ploughing, the fruit of patient work and a promise of fruit in the future. The Rhône is the future promise of effort. In short, it's a tree.
This closes the portrait of the third river-tree that I share with you: the Populus Nigra Rhodanus.
At the height of its power, past the thousand-year-old city of Arles, the Rhône splits in two and flows peacefully through the vast delta it has created. It's time to go to bed, and the journey comes to an end: the Camargue, an avian haven where pink flamingos and buzzards live alongside rice fields, salt marshes and oil refinery chimneys. The Rhône, even more than its neighbour the Loire, connects like a thread places that everything opposes: grey, barren and icy mountains, the chalky vineyards of Champagne open to the Germanic world, the misty marshes of the Dombes and finally a Mediterranean delta, warm and humid, full of canals, ponds and gullies where insects and birds thrive. It is in this last place that the river dies magnificently in the Mediterranean Sea, only to take another form later...
In which tree might the Rhône find an equivalent? I suggest the Black Poplar. A robust tree, accustomed to a wide range of temperatures, it thrives in both warm and chilly climates, and thrives by the river in damp soil. It is no coincidence that it is found in large numbers where we live: as a strong, fast-growing tree, it was valued for its wood, which was used for all kinds of purposes. A tree that has co-evolved with us, with its straight form and tall stature.
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THE NILE
The Nile. There's so much to say about this river, like all the others in the series. Like the Rhône, it flows into the Mediterranean and, like the Amazon, it holds a world record for size, as the Nile is simply the longest river in the world. Like other African and Asian rivers, it has fascinated and tormented Western explorers who have spent generations tracking down its source, only to contract the beautiful disease known as ‘Egyptomania’...
But the Nile is quite unique, on closer inspection...
Let's start with the atypical shape of this river-tree: a relatively long watershed, it contains one of the largest lakes on our planet at its summit, Lake Victoria, surrounded by robust, well-stocked branches with a very thick trunk known as the White Nile. Once the tree reaches mid-height, the trunk thins and loses most of its branches and leaves as it approaches the ground, where the delta forms a curious root system.
A strange tree!
Why? The rain, it's always the rain. And the heat. Whether we're talking about rivers or plants, these two factors are the law.
At the top of the tree, where the first rivers begin, the land is blessed by the monsoon and fed by it. The largest tributaries of the Nile, the White Nile for example, form the biggest branches of the tree. As we go north, that means lower down the tree, the water is scarce, and the Blue and Red Nile, as well as other tributaries, are nothing more than hollow, spindly branches that join the trunk and make a meagre contribution - not enough to compensate for the formidable evaporation of tropical latitudes - to the flow of the river, which concentrates the little water that remains in the tree. Some of these dry branches, which cross the desert and cut into the rocks in violent spurts (‘flash floods’, for example), even disappear during the dry season, only to reappear at the first rains: these are the wadi, ephemeral streams.
Fascinatingly, but far from inexplicably (which I think is the beauty of geography), the boundary between the dry zone, where rainfall is close to zero, and the wet zone, where the monsoon makes the river-tree green and the landscapes lush, corresponds more or less to the boundary between the Semitic languages (dialects of Arabic) and the Nilo-Saharan languages, with a little corner of the Bantu family to the south. Once again, the river brings together places with contrasting geographies, languages and cultures.
This shrinking and retracting of the river-tree is almost reminiscent of the survival strategies in the face of drought that are characteristic of many plant organisms living in an arid environment. During the dry season, the flow drops drastically, only to increase again in the wet season, by a factor of 50 for the Blue Nile! And then humans started to prune the tree...
The 1960s were a period of great demographic growth in Egypt, and the growing need for electricity justified the construction of a colossal dam in the south of the country, upstream from Aswan, resulting in the creation of a gigantic lake in the middle of the desert and, above all, the end of flooding on the Nile downstream of the dam. The alternating high and low water represents the heartbeat of an entire river, a long, deep beat spread over several months, between periods of intense rain and periods of merciless drought.
For the Nile, this heartbeat was also that of an entire people from Antiquity who lived thanks to these floods, believed to be attributed to the gods because they were so vital for agriculture, owing to the fertile silt that the water deposited on the flood plains. There are few peoples in history whose past, present and future are so closely linked to a river that forms, in the literal sense of the word, a ‘lifeline’. A map of Egypt's population density would be worth a thousand words. It goes without saying that for the ancient Egyptians, the river was at the centre of daily and sacred life: the east bank was that of humans, while the west bank, that of the setting sun, was the domain of the spirits and gods. It was also were kings were buried in the famous Valley of the Kings. In fact, look at the map again: don't you see a mummy in the shape of the tree? Islam long ago swept away these pagan beliefs with its pantheon inspired by nature and, today, the dam allows better control of irrigation and generates huge quantities of electricity for a population in need. But the Nile has changed forever.
The Nile now flows through 11 countries and 20% of Africans live in its catchment area, a total of 257 million people (106 of them in Egypt alone, and that in a narrow strip of land around the river), making the watercourse the subject of serious tensions between countries over the issue of dams and water intakes. Imagine a tree with golden fruit growing right in the middle of the agricultural plots of 11 different farmers. Who could claim the right to pick the fruits of discord? Who will keep the most water for themselves?
To conclude this long African journey, beginning in the African Great Lakes region and the Ethiopian highlands, the Nile ends its earthly life in a vast delta where, from the sky, we can imagine the tree peacefully taking root in the sea. So the portrait of the Nile River is almost complete: now we need to find the tree it incarnates. For this imaginary botanical prerogative, I propose the date tree. An emblematic tree of the North African desert, it is not only perfectly indigenous to the arid part of the Nile basin, where it has been appreciated for its fruit for thousands of years, but a dreamer's mind will also see its form in our River Tree: a crown of leaves at the top of the tree, followed by a trunk bereft of any branches. In short, a tree split into two distinct parts, like the wet and dry halves of the Nile, with a clear continuity between the two.
This concludes the portrait of the fourth River Tree that I share with you: the Nile Date Tree, Phoenix Dactylifera Nilus.
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THE GANGES-BRAHMAPUTRA
The Ganges-Brahmaputra... Another strange tree! First of all, look up there, far up there in the clouds: its crown is the highest in the world, along with the snow-capped peaks of Nepal, which happily exceed 8,000 metres. Next, admire its double-trunk structure, as if, cut off in its growth, the river had grown back again by splitting into two, a hydra river, like the aquatic animal of the same name that scientists believe to be immortal and capable of regenerating itself by forming new branches. We could also see a mountain shrub, tormented in its growth by the cold and icy winds of the Himalayas, so particular is its shape, close to the ground and squat...
Finally, there are its fabulous roots, which form the largest delta and mangrove forest on our planet, the Sundarbans: a forest on roots! Could these be the mycorrhizae that scientists refer to, the organic, symbiotic extensions created between the tree's roots and the soil?
There are undoubtedly few rivers on Earth that connect, with their long blue thread, universes with such opposing geographies: the highest mountains on the planet, and the Tibetan high plateau, two desert, uninhabited, dry, and cold environments that are linked by the river to a mangrove forest, a semi-arid steppe, and a vast hot and humid plain, populated like nowhere else on Earth.
In any case, this river-tree that covers 2.6 million square kilometers is powerful: every summer, the prodigious masses of snow that lie dormant on the summit, which weigh heavily on the poor branches, melt and, once they leave the mountain, join the rainwater of the eternal monsoon that waters the entire Indian subcontinent with much-awaited water. To say that this tree is well-watered is almost an understatement: the city of Mawsynram, in Meghalaya (literally "The abode of the clouds") in Northeast India, receives an annual rainfall of 11.80 meters! Add to that the millions of tons of sediment borrowed from the mountains by the flowing water, and which are dumped along the course of the rivers, and ask yourself how, then, this tree could not be fabulous?
River Tree, River Hydra: just like this eternal creature with incredible resilience, the Ganges-Brahmaputra basin is a subject of endless interest for those who love the Indian world and geography. In the vast Ganges plain, deep within the bright green foliage of the tree revived by the warm summer rain, was born one day the "eternal religion," the sanatana-dharma, Hinduism. Then, Buddhism was born on another branch, followed by many other beliefs and faiths too numerous to find a branch for each, quickly leading to the necessary coexistence, the blending of religions and beliefs, not to mention those that arrived from other trees: Islam, Christianity, and even Zoroastrianism, which has almost disappeared elsewhere.
The same goes for languages and cultures: the Indian, Bengali, Nepali, Tibetan, and Bhutanese parts of this tree account for hundreds of languages in total, with a patchwork of cultures forming a bright and colorful foliage.
Coming back to languages: if this tree harbors such linguistic diversity on its branches, it is not a coincidence of evolution. It is the most populated on the planet with around 630 million inhabitants living in its large canopy. Let's think in particular of the mountainous areas with their very rich ethnolinguistic diversity. 630 million? 8% of humanity. Yes, the Ganges-Brahmaputra is a tree that grows on very fertile land, a fertility coming from mineral deposits borrowed from the mountains and brought by the rivers, much like enriched sap from the leaves that travels to the rest of the tree, making it grow year after year. This great tree is also blessed with an ideal climate for crop growth: alternating dry and wet seasons, heavy rainfall, and high temperatures that allow for multiple harvests each year, enough to feed many mouths. It is this plain that gave birth to some of the first agrarian societies of humanity and explains today's demographics: 630 million humans on a vast tree now violently battered by heatwaves, intense water stress, and other climate change-related diseases that threaten to uproot some of the oldest trees on Earth.
Many rivers on Earth are the subject of worship and hold a sacred dimension among the civilizations that sometimes owe their existence to them. The Ganges and the Brahmaputra are no exception: they are even emblematic cases. The rivers that form the branches of this River-Tree are also revered and placed at the rank of divinity by the Hindus, who see them as a mother (Ganga Mata) or the son of Brahma (Brahmaputra). They also make pilgrimages to the source of the Ganges, where they scatter the ashes of their deceased loved ones, who join the great tree for eternity. Every day, millions of Hindus perform their morning ablutions in the river water, send plates of offerings floating, or offer milk to the watercourse as a sign of reverence for the supreme nature embodied by these sacred rivers in their pantheon.
Let's not let the one on the Ganges Brahmaputra river succumb to sickness, for it evokes a very real tree: the banyan, Ficus benghalensis. What better species to represent our River Tree? Native to the Indian subcontinent, its branches bear the long, dense history of a thousand peoples, and it is shrouded in a million tales and legends. Even its shape evokes the tree illustrated on the map: a multiple trunk and chaotic roots, piercing the ground in multiple places. Like Hinduism and its pantheon of countless varieties, the banyan has no real centre and is made up of hundreds, even thousands of trunks.
This brings us to the end of the portrait of the fifth River Tree that I share with you: the Banyan Ganges Brahmaputra, Ficus Benghalensis Brahma-Ganga.
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THE SEINE
And here's the sixth river-tree I'm sharing with you: the Seine! It's a river that's been in the news a lot this year, in 2024: a major clean-up programme for the Olympic Games, including the opening ceremony and sporting events, the reconstruction of Notre-Dame, and many other projects that have put the spotlight on this great tree, in better ecological health today than it was in past decades. It was a sick tree, but now it's well again. The Seine, like the tree, experiences a rather sudden rise in sap at times, the ‘mascaret’, a powerful and spectacular tidal wave originating at its mouth. Unfortunately, this poetic phenomenon has disappeared as the river bed has been dredged to make way for container ships. This is a far cry from Gaulish times, when the goddess Sequana, associated with the Seine, was worshipped, just like water and rivers.
France's third largest river, it is, like the Rhône, a transboundary river, as a tiny part of one of its main tributaries, the Oise, originates in Hainaut in Belgium! Like the Rhône, the Seine is misnamed from a strictly hydrological point of view: the Aube and then the Yonne each have a greater flow than the Seine when it meets them. And like the Rhône, the reason for this ‘mistake’ is undoubtedly the immense importance of the Seine in river transport and the passage from one catchment area to another, which touch each other at the tips of their branches. In fact, the Seine tree touches three rivers at the same time at two points, in what is known as a hydrographic tripoint. At one of these points, the Seine, Rhône and Meuse basins meet, while at the other, the Seine, Rhône and Loire basins touch. Seen from the sky, could this be a sign of the ‘crown shyness’ observed in trees when they come into contact?
In the collective mind, the Seine embodies the French river par excellence, with cities such as Paris, Rouen, Chartres, Reims and, in general, the Île-de-France region nestling in its branches, the cradle of the Kingdom of France, of royal, then parliamentary, then presidential power... It was even on the branches of the Seine (between Tours, Paris and Rouen) that the langue d'oïl, then French, evolved and spread to the rest of the country. It was also at the bottom of the tree, from Paris to Normandy, that many of Impressionism's masterpieces were created, painting and celebrating the river, its reflections, its light and its atmosphere on canvases. Before that, it was the river that enabled the Vikings to get deep into the lands and villages of frightened peasants, to plunder and kill, but also to leave a remarkable influence with repercussions on Norman genetics and culture. The Vikings even came up with a name for the Seine, signa, which is still used today in Icelandic.
Unlike other tree rivers presented before it, the Seine is not a very large one: its catchment area, the foliage, covers 80,000 square kilometres, while its altitude rarely exceeds 300 metres, with the exception of the Morvan in the south. Nor is it a tempestuous river, with a climate of moderate or even fairly low rainfall on some of its branches, particularly in the Beauce region. Its last hundred-year flood was in 1910, but these have since become rare. There are many dams and locks to regulate the flow of the river, which is home to two of France's most important river ports: Paris and Rouen, the latter being Europe's leading cereal port and connected to the Beauce, a section of the tree that feeds many others with its fruit. A lot of people live in this tree: 30% of the French population, or more than 20 million people.
It is in this part of the tree, the Basse-Seine and Seine-Maritime, that the trunk twists into curious shapes, as if fashioned by a skilled arboriculture enthusiast, to form meanders that are actually the result of the gentle slope. There are also numerous islands, forming long knots in the wood, stretched to absurd dimensions like the island of Saint-Denis, where the ‘Îlodionysiens’ can boast of living in a commune that follows the contours of an island perfectly, 3.5 kilometres long and 100 to 300 metres wide!
The riverbed in this part of the tree is so wide that once past Rouen, there are few bridges to span the mighty waters, but plenty of container ships and ocean-going vessels. The most famous of these bridges is undoubtedly the Pont de Normandie, because of its immense dimensions, and the Pont de Tancarville, which is older but revolutionary, as it replaced the traditional shuttles. Its modern structure (1.4 kilometres long, completed in 1959) left its mark on the people of Normandy, who then named their clothes racks after the bridge...
So which tree best represents the Seine? A bit of research led me to suggest ash: a very common tree in the region, it was once used to make oars for boats, a key element in commercial river craft, but also in warfare, the Viking ships that once plied the Seine in the thousands, transporting ideas, goods and people.
This completes the portrait of the sixth River Tree that I share with you: the Seine Ash, Fraxinus Sequana.
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THE MEUSE
It is possibly the second oldest river on our planet, and its source is in France...! This ancient tree river, which flows towards Belgium and the Netherlands, is between 320 and 340 million years old. So it's no surprise to see its strange shape: anyone who has ever seen reconstructions of the first trees (that ‘appeared’ on Earth a few million years before the Meuse itself) knows just how different they could look, almost alien...
A bit like the River Meuse, which stretches from the French and Belgian Ardennes, two very rural, wooded and sparsely populated areas with a rugged topography, to the north of Wallonia and the Netherlands, two areas that are in stark contrast to the rest of the tree: flat and densely populated. The Meuse is then joined by new tributaries that add to its foliage, transforming the watershed into a densely populated, artificially developed area that has been profoundly transformed by human activity.
The structure of the tree itself has not been spared by the creative hand of the ecosystem engineers that we are: several of the lowest branches of the Meuse are in fact canals, a complex root system, a sublime branch with multiple nodes, locks and dykes, the result of a skilful balance between facilitating river trade in what is the maritime heart of Europe and fighting against what lies at the end of the river: the ocean. It is in the delta of the Meuse, shared with the Rhine, that a number of historic hydraulic structures can be found, built by the Netherlands in their fight against the sea and storms, those terrible sea surges caused by the weather's incursions inland.
If the Meuse were a tree, it would undoubtedly be the yew: a tree of great longevity, reflecting the age of the River Tree, it lends itself very well to pruning, again reflecting the delta largely modified by humans, and finally it is generally small in size: the Meuse is decidedly not a giant tree, especially compared to the other rivers in this series. Symbol of death, it also resonates with Verdun, upstream from the river where hundreds of thousands of soldiers fell a century ago.
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THE CONGO RIVER
Let's change latitude once again to discover the second African river in the series, a tree-river that mirrors the Amazon, one growing right opposite the other, separated by the vast Atlantic Ocean, which has kept these two trees apart. They could have known each other, touched each other, in a distant geological era when South America and Africa were one inside the other. Despite this separation, the two rivers have much in common: the Congo is second only to the Amazon in terms of its flow, a vital flow of sap that flows through the tree and brings life, a life that is remarkably constant throughout the year: the flow of sap and water remains unchanged over the months thanks to this tree, which is large enough to capture the rainy season in several places as it moves through the equatorial zone of the African continent.
A second similarity: the Amazon and the Congo are both guardians of a prodigious equatorial rainforest in their great green canopies. Here too, the Congolese equatorial forest is second only to the Amazon. As for the trunk of the Congo tree, the main course of the river, it is quite curious and is said to reach depths of 220 metres in some places, harbouring an abyssal fresh water fauna. You can compare this with the mysterious underground rivers of the Amazon, dozens of kilometres wide.
These rivers and equatorial forests are still full of secrets, as are their ethnically diverse populations, still living in isolation.
If the Congo were a tree, for me it would be a Sapele, whose precious red wood reflects the rich diversity of the river that grows throughout its basin. It's also a tree of colossal proportions, generally 60 metres high, once again on a par with the enormous tree-river that is the Congo River.
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THE GARONNE AND
DORGOGNE RIVER
Let's return to France to discover another splendid river tree that adorns our country, a tree with two trunks, the Garonne and the Dordogne, both of which join in the wide Gironde estuary, a powerful trunk making the transition to the Atlantic world. It's a big tree that casts its shadow over what is known in France as the South-West, a vast territory made up of many different regions: Périgord, Quercy, Armagnac, the Auch region, the Toulouse region, the Tulle region... All names that conjure up images of traditional gastronomy with famous dishes and spirits, medieval villages on cliffsides and wood crafts.
All in all, the Garonne-Dordogne tree's foliage is lush and green, benefiting from a warm, sunny environment (thanks to the South-West climate), but sparsely populated. Apart from the two metropolises of Toulouse and Bordeaux, this is a very rural tree with a strong agro-pastoral tradition, for example in the Pyrenees (where the branches of the tree take on a fractal nature) or towards the peaks, on the way to the Massif Central. The rest of the tree is cultivated in places, but still relatively wild, with a large wooded area.
If the Garonne Dordogne were a tree, it would perhaps be a black walnut tree: a tree found widely in the catchment area of both rivers, long cultivated for the oil from its fruit and its wood, which is highly valued by the region's craftsmen. The walnut tree has become an important part of local culture, with the Périgord walnut, a protected designation of origin product, once traded by boat along the rivers in the catchment area. It is a tree that thrives on the rich, deep alluvial soils found near rivers.