From Iron Curtain to Green Belt. Between Austria and Slovenia, where the Wall saved biodiversity.

On his tractor, Josef Hadler mows a meadow on the former Iron Curtain that separated Austria from Yugoslavia. Not to exploit the land, but simply to preserve the biodiversity of this exceptional site. "Yesterday, a buzzard followed me five meters away," the 54-year-old farmer from Sankt Anna am Aigen, who performs extraordinary work for the nature conservation association in his region, southeastern Styria, told Agence France Presse. We are on the border with Slovenia, and very close, at least as the crow flies, to the border with Hungary, on the opposite side of the triple border between Vienna, Ljubljana, and Italy .

The surprise effect of the “blocks”

On the fifteen hectares of protected land in this village, endemic flora and fauna species that had disappeared elsewhere have managed to survive—an unexpected effect of the Cold War, but also seen on other former dividing lines between the two curtain walls. "No one would have built their house directly on the border, which has remained green," explains Johannes Gepp, local president of the environmental protection organization Naturschutzbund, which purchases plots of land from farmers. Although south-facing, this meadow had once been converted into a field for intensive corn cultivation. But it proved too dry, and the farmer gladly sold it fifteen years ago to purchase another that offered a good yield. "From a monoculture, we've gone to growing 70 to 80 species per 100 m²," eliminating fertilizers and mowing only once or twice a year, explains Markus Ehrenpaar, general director of the Styrian Naturschutzbund.

For silage, Hadler usually mows his farm's fields five times a year. This allows him to feed hay to his livestock. However, this practice prevents flowers from growing, although he has noticed that in fifteen years, many plant and animal species have returned to this carefully managed plot. These include the bloodroot, the only plant exclusively for two species of butterflies, and the yellow sac spider, a poisonous spider. Maintenance is essential because it prevents the proliferation of grasses at the expense of wildflowers. The farmer benefits: he is compensated for his work and has the right to harvest the hay, which will be used as bedding, since hay cut in protected meadows is indigestible for his livestock.

School trips and "soft" tourism

Another advantage, explains the village's mayor, Andrea Pock, 46, is that these "wonderful natural gems" are used for biology education during school trips. "A kind of soft tourism has developed," she rejoices. "Many people come to see the flowers and observe the insects." They also read the signs reminding them of the dark past of the fortified and mined border, presumably intended to discourage easterners from crossing to the west.

To ensure genetic mixing, which is the key to the long-term survival of these tiny, species-rich areas, however, crossing points must be created in other areas. This costs millions of euros each year, because "land is very expensive," Gepp confirms. The region, the government, and the European Union (EU) are contributing to the revival of this heritage.

The stakes

The stakes are high. Austria has 1,300 kilometers of green belt, which it shares with the Czech Republic, Slovakia, Hungary, and Slovenia. Currently, only a third is protected. Across the continent, vast areas transformed into ecological paradises by the absence of human activity extend for over 12,500 kilometers from Norway to Türkiye.