How Low Europe's Forests Fell, and How They Came Back (1400–2025)

In 1805 the Danish crown put every remaining wood in the kingdom under protection for good. A protected wood that was felled had to be replanted, and the woods were to be fenced. There was not much left to protect: around 1800 forest covered somewhere between 2 and 4 per cent of Denmark, a country whose natural cover is beech wood. A century later Ireland and Britain went lower still. Ireland had less than 2 per cent forest at the start of the twentieth century, and Britain's woodland bottomed out at under 5 per cent of the land in 1919.

This map follows Europe's forests from 1400, when woods had crept back over fields emptied by the Black Death, through four centuries of clearing to the low point of the 1800s, and then through the return. The return is real, but in the countries that fell lowest the forest came back as something new: plantations of conifers, many of them species that never grew there before, and the map gives them a colour of their own.

Four Centuries of Clearing

The map opens on a pause. The plague of 1347–51 killed perhaps a third of Europe's people, and abandoned fields went back to scrub and then to wood, so 1400 is a relative high point. When the population recovered, so did the axe. Land was cleared first for fields and grazing, and much of what was left was cut for fuel: for every hearth, and for the trades that ran on wood and charcoal, from glassworks to iron furnaces and the smelters of the mining districts. Venice was already reserving the beech of the Cansiglio forest for the oars of its galleys from 1548.

Shortage made people think about supply. In 1713 Hans Carl von Carlowitz, a mining official in Saxony, published Sylvicultura oeconomica, which argued that a forest should be cut no faster than it grows back. His 'nachhaltende' (sustained) use of the woods is where the German word Nachhaltigkeit, sustainability, comes from. War could undo the clearing for a while. The Thirty Years' War (1618–48) emptied so much of Germany that woods spread over the abandoned land before the farmers returned.

On the map, clearing shows as rust: land that was forest in 1400 and no longer is. Between 1400 and 1900 the forest the map shows shrinks by about two-fifths. Watch the mixed forest of central Russia turn rust between 1700 and 1900 as farming spread east and south, and watch Denmark's woods dwindle to a few specks by 1800.

Why the Atlantic Edge Fell Lowest

The countries on Europe's Atlantic and North Sea edge started low and went lowest. Much of their natural forest was gone long before 1400 (the sand colour on the map), cleared by farmers and kept open by grazing, and on the heaths, moors and bogs of the windy west the trees did not come back on their own. They could also manage with little wood of their own, because they had other fuel and timber: peat in Ireland, the Netherlands and Denmark, coal in Britain, and timber shipped in from the Baltic and Norway.

At the low point the numbers were tiny. Denmark had perhaps 2 to 4 per cent woodland around 1800 (the map's caption uses 2–3 per cent; Danish sources give about 4). Ireland had under 2 per cent at the start of the twentieth century and 1.4 per cent when the Irish state was founded in 1922. Britain was under 5 per cent in 1919, after the First World War had felled much of what was left. Even France, a large and well-wooded country, reached its low around 1830 with about 9 million hectares of forest, roughly a sixth of its land. Compare Finland and Sweden, where on this map the forest never falls much below half of the land.

Laws, Coal and Planting

In the nineteenth century the tide turned. Coal replaced wood as fuel, first in Britain and then wherever railways could carry it, which took the pressure off the woods that were left. Governments wrote forest laws: Denmark in 1805, France its forest code in 1827, Switzerland its federal forest law in 1876, after floods that were blamed on bare Alpine slopes. And states started to plant.

The biggest early project was in Gascony. A law of 19 June 1857 ended the old sheep farming on the marshy heaths of the Landes, where shepherds had walked on stilts, and the land was drained and sown with maritime pine. The Landes forest now covers about 10,000 square kilometres and is the largest man-made woodland in western Europe. Ireland's state forestry began at Avondale in 1904. In Britain the Forestry Act of 1919 created the Forestry Commission to build a strategic reserve of timber after the war. Spain followed with a national reforestation plan, drawn up in 1938–39 and carried out from 1940, mostly with pines and later with eucalyptus.

On the map, planted forest is the blue-green layer. It appears in 1900 in Germany, Czechia, the Low Countries, Denmark and the Landes, where conifers had replaced the natural broadleaf woods or been sown on heath, and in 1950 in Britain, Ireland, northern Portugal and Galicia.

What Came Back

Europe's forest grew through the twentieth century and is still growing, but what came back depends on where you look. In the north-west it is mostly planted. Ireland had 11.6 per cent forest in 2022, according to its fourth national forest inventory; 69 per cent of it is conifer. Britain is back to about 13 per cent woodland, and conifers make up about 51 per cent of the United Kingdom's woodland, 74 per cent in Scotland. Denmark had about 11 per cent forest in 2000, nearly two-thirds of it conifer.

Further south the return was mostly natural. France's forest had nearly doubled from its 1830 low to 17.5 million hectares, 32 per cent of the country, by 2023, and about 70 per cent of that gain is woodland that grew by itself on farmland people had left. Abandoned farmland did much the same in the hills of southern Europe, which is what the map's caption for 2000 is about.

Planted forests bring their own risks. Spruce planted far below its natural mountain home suffered badly in the dry summers from 2018: satellites measured about 500,000 hectares of lost tree cover in Germany between January 2018 and April 2021, much of it spruce killed by bark beetles, as in the Harz. In the pine and eucalyptus plantations of central Portugal, the Pedrógão Grande fire of June 2017 killed 66 people. Both are pins on the map; neither is part of the forest model.

How to Read the Map

Greens are forest, coloured by natural forest zone: dark green for boreal pine, spruce and birch, mid green for the mixed zone, light green for broadleaf oak, beech and hornbeam, grey-green for mountain conifers and olive for the Mediterranean zone of holm oak, cork oak and Aleppo pine. Blue-green is planted forest. Rust is land that was forest in 1400 and has been cleared since; it turns green again where the forest returns. Sand is land whose forest was already gone before 1400. Tundra, bare mountains, large open mires and the southern steppe are left blank, because they were never forest.

Step through the ten keyframes and watch the rust spread through the mixed forest of central Russia and Poland until 1900, the British Isles and Denmark almost empty of green in 1800 and 1900, and the blue-green plantations appear from 1900. Six pins pause playback: the Black Death, Carlowitz in 1713, the Danish forest act of 1805, the Landes law of 1857, the Forestry Commission in 1919 and the spruce dieback in the Harz from 2018. Eight small dots, from the Białowieża forest to Pedrógão Grande, tell their story when you hover over them. Of all the land the map colours, forest covers nearly two-thirds in 1400, under two-fifths in 1900 and about half in 2025.

How the Map Was Made, and What It Cannot Tell You

The map is a model built on national figures. For each country and date it takes a forest total from national forest histories, from the reconstruction by Kaplan, Krumhardt and Zimmermann (2009) and, for recent decades, from FAO and Forest Europe statistics, and spreads that total over a grid of cells about 5 by 9 kilometres. The 2000 frame is tied to satellite data: the forest stands where the land-cover map of the ESA Climate Change Initiative saw trees in 2000, region by region. The 2025 frame keeps that pattern and places the change since 2000 where ESA WorldCover saw trees in 2021; its totals come from the latest statistics, not from a measurement made in 2025.

Earlier frames are run backwards from 2000. Forest is taken away where the KK10 land-use reconstruction (Kaplan and Krumhardt, 2011) has farmland at that date and given back where farming spread later, and the model never clears forest where KK10 has no farming, which keeps Lapland, the White Sea coast and the far north wooded throughout. The forest zones are potential natural vegetation, drawn from climate and altitude (WorldClim 2.1): what would grow there without people. That is why the pine forests of Poland and north-east Germany, largely planted, appear in the mixed zone, where pine also grows naturally.

Use the map for the shape of the story, not to look up a parish. The national totals follow the record, but before 2000 the place of a wood inside a country is the model's estimate. The map cannot tell coppice from high forest or wood pasture from closed woodland, and its smallest specks disappear, so Denmark's remnant of 1800 shows as a few dots. Patterns before 1800 are indicative.

Chronological Timeline

• 1347–1351 — The Black Death; abandoned fields turn back to woodland
• 1548 — Venice reserves the Cansiglio beech forest for galley oars
• 1618–1648 — The Thirty Years' War empties much of Germany
• 1713 — Carlowitz publishes Sylvicultura oeconomica
• c. 1800 — Denmark down to 2–4 per cent forest
• 1805 — Danish forest ordinance (Fredskov)
• 1827 — French forest code
• c. 1830 — France at its forest low, about 9 million hectares
• 1857 — Landes law: Gascony's heaths sown with maritime pine
• 1876 — Swiss federal forest law
• 1904 — Irish state forestry begins at Avondale
• 1919 — Forestry Commission founded; Britain under 5 per cent woodland
• 1922 — The Irish state starts with 1.4 per cent forest
• 1940 — Spain begins its national reforestation plan
• 2017 — Pedrógão Grande fire in central Portugal
• 2018 — Drought and bark beetles start the spruce dieback in Germany
• 2022 — Ireland's forest cover reaches 11.6 per cent
• 2023 — France's forest at 17.5 million hectares, 32 per cent of the country