Here is a river that is particularly unknown to the general public despite its exceptional characteristics, and it is perhaps its remoteness that accounts for this discretion. The Yenisei is the fifth longest river in the world and the queen of Arctic rivers, where no other river surpasses it in length and flow.

The other giant rivers in the series, such as the Ganges, the Amazon, and the Nile, connect environments that are separated by distance, but above all by climate and terrain. The Yenisei, on the other hand, does not experience extreme climatic variations but is 5,500 kilometers long if we take as its source the most distant Mongolian streams that flow in the steppes of Central Asia, in the most isolated region of the world. Ulaanbaatar, where tributaries of this giant river flow, is located at 48°N, the same latitude as the city of Brest where I am writing these lines, but the raindrops that fall north of the city will travel a long way to the frozen polar seas at 70°N, well above the Arctic Circle!

This journey is likely to take a long time, because on the way to the sea lies the jewel of Siberia, a treasure of the Tree, a frozen fruit: Lake Baikal, the oldest and deepest lake in the world. If a drop of water lingers there, it could embark on a journey 1,000 leagues under the sea, or rather 1,642 meters below the surface. Does the lake, which contains nearly 23% of the world's fresh water, make the Yenisei the most important river-tree on our planet, if not the heaviest and most voluminous? In any case, Lake Baikal is an oasis of life in harsh Siberia, with thousands of animal and plant species, many of which endemic to the region, including seals, bears, and wolves thriving around this lake, which remains frozen for four months of the year. The rest of the Yenisei is no less impressive: further north, halfway along its course, it remains frozen for more than half the year. This is a far cry from the Mississippi, a major transport artery.

One tree embodies this Siberian spirit, marked by extremely harsh winters, isolation, and the rhythm imposed by winter: the Dahurian larch, Larix gmelinii. This conifer with deciduous needles—which fall in the fall, when the tree goes into hibernation—grows throughout the Yenisei basin, on both marshy and well-drained soils, and can tolerate unimaginably cold winters with temperatures as low as -70°C. It is quite simply the champion in this field. I believe that it is this absolutely remarkable ability to survive where no other tree could that makes it representative of the river and its harsh geography and unforgiving winters.

The Yenisei larch, Larix yeniseica