“The Treeline: The Last Forest and the Future of Life on Earth”
By Ben Rawlence. Press Saint-Martin, 2022. 307 pages. $29.99.
The boreal forest, that ring of trees that circles the globe at high latitudes, is the largest living system after the ocean; it is also the “lung” of the planet and therefore the key to the health of our planet. Ben Rawlence, who lives in Wales and whose latest book was about a refugee camp in Africa, shared his human rights concerns at the disastrous effects of climate change. From 2018 to 2021, he traveled the forests of the north – in Norway, Russia, Alaska, Canada and Greenland – to meet locals and scientists and to learn for himself what is happening with the trees. further north and the life associated with them.
How interesting can treeline be? Incredibly interesting, it turns out that the subject is in the hands of such a talented researcher and writer. A book about trees can, we find, turn the page. Part travel adventure, part deep dive into emerging science, part reflection on our history on Earth, part philosophical questioning of Earth’s fate – “The Treeline” is a vivid and beautifully written weave of fascinating topics.
Organizationally, the book travels the world, with each chapter focusing not just on a different forest, but on the tree species most important to that forest. A map at the beginning, looking towards the North Pole, shows the forests, their northern extent, and the main communities the author visited.
Rawlence begins in its neighboring Scotland, considered the limit of the Arctic treeline in Europe, although most of its trees were felled centuries ago. Forest succession after the last ice age led Scots pine to cover about 80% of the territory in the past. Today, ‘rewilding’ efforts aim to restore some of this great woodland, but global warming projections suggest the UK’s climate will soon be too inhospitable for pine trees.
In the next chapter, featuring Norway and the downy or European white birch, Rawlence visits the Sami reindeer herders of the far north. Here and elsewhere, the author makes it abundantly clear that forest health is directly linked to human rights and the abilities of indigenous peoples to maintain their cultural connections and livelihoods. The warmer, wetter weather has caused the Norwegian birch to “race” across the tundra, reducing the habitat required by reindeer and their herders.
In the chapter on Russia, featuring larch, Rawlence visits several forest areas in winter and meets with scientists and indigenous people. He travels hundreds of miles in a tank-like vehicle with huge tires to find the world’s northernmost trees – spindly larches that grow in extreme cold on thick permafrost. Elsewhere, the thawing of the permafrost causes the water tables to rise and the “drowning” of the larches. He learns that scientists predict that at least 50% of Siberia’s forest will turn into treeless steppe by the end of this century.
By the time Rawlence investigated Alaska’s treeline and dominant spruce species, the world was in the midst of COVID-19 lockdowns. Unable to visit in person, he did an impressive job studying maps, photos and reports and talking to researchers and residents. As he points out, “Alaska is the most studied region of the Arctic; the United States has the resources and the scientific clout that other nations lack… a frontier in our understanding of what is happening in geographical and scientific terms. He details his conversations in Alaska with Ken Tape, who studied how beavers have recently transformed the landscape; writer Seth Kantner, who grew up along the Kobuk River treeline; and Roman Dial, who has studied the evolution of vegetative dynamics, particularly that of spruce, in the Arctic for more than 40 years. It also details the influences of fungal networks on forest health, how warmer air affects photosynthesis, and the relationship between Alaska spruce evapotranspiration and precipitation in the US Midwest.
In Canada, Rawlence spent time in Ontario with Diana Beresford-Kroger, “one of the most eminent scholars of the boreal forest” – and, we learn, the model for a character in the novel “The Overstory” by Richard Powers – then in and around Churchill on Hudson’s Bay. Here, we learn how critical the northern forest is to regulating water, air, soil, climate, and ocean productivity. We also learn where the subtitle of the book comes from, referring to “the last forest”. Beresford-Kroger believes that the Amazon and other rainforests are “probably finished,” threatened because they are not just from intentional deforestation, but from drying out and burning. The boreal forest, spanning a wide range of temperatures, has perhaps the best chance of adaptation. In Canada, its flagship species is balsam poplar, or cottonwood poplar.
Rawlence’s last stop – in organization, not in real time – is Greenland. As the island’s ice cap melts, the land becomes more habitable for trees, of which there are four native species, primarily mountain ash or mountain ash. Rawlence joins a tree-planting group and discusses the emerging field of “strategic ecology,” which is not based on current climatic conditions but on assumptions about the future. “Assisted migration” is another term related to helping species, including trees, move to places where they could survive a warmer world.
Ultimately, by showing how the boreal forest interacts with all life on Earth, Rawlence paints a grim picture of where we are headed. It does not offer false hope but rather speaks of a necessary change in the way humans live. “Curiosity and observation are the humble but radical conditions for a new relationship with the Earth. Systems change when there is a culture that demands it. The revolution begins with a walk in the woods. Rawlence’s contributions to the cause include founding and directing Black Mountains College, a school in Wales dedicated to teaching climate change mitigation and adaptation skills.