The Earth’s forests have been changing ever since the first tree took root. For 360 million years, trees have grown and been felled through a dynamic mix of hurricanes, fires and natural regeneration. But with the dawn of the 17th century, humans began replacing large swathes of forest with farms and cities.
The global pace of deforestation has slowed in the 21st century, but forests are still disappearing – albeit at different rates in different parts of the world. Boreal forests, which grow in the far north of the world and across vast areas of Canada and Russia, are expanding further north as the climate warms, turning tundra into new woodland. Many temperate forests, like those in Europe, saw their greatest destruction centuries ago. But in the tropics, forest loss is accelerating in previously pristine wilderness.
As forest cover has fluctuated over time, the biodiversity within forests has changed too. Forests support around 80% of all species living on land, but the species we see on our woodland walks today are likely to be different from those people saw in the past. Many species, such as the Alpine longhorn beetle, survive in intact old-growth forests, while species like the red fox have managed to thrive in areas with higher human impact.