Farmers are abandoning their land. Is that good for nature?

In southern Bulgaria, in the village of Tyurkmen, many brick houses sit empty. Their tile roofs are falling in. Gergana Daskalova, an ecologist who spent summers here with her grandparents as a young girl, points to a child’s book lying amid the ruins. “Somebody poured their heart and soul in creating a home, and now it’s just collapsing,” she says.

A century ago, a thousand people lived in this village. Today, there are only about 200. People left for jobs in Bulgaria’s cities, or abroad. Their heirs may still own land around the village where crops once grew, or sheep grazed, but much of that land now sits unused. Shrubs and small trees are taking over.

“My family has fields that we inherited from my grandparents, [but] I don’t know where they are,” Daskalova says.

This is a common situation in Bulgaria, and in a surprising number of rural villages around the world. Even while large farming enterprises clear forests in Brazil or Bolivia in order to graze cattle or grow crops, some farmers elsewhere are walking away from their land, letting nature reclaim it.

Abandoned farmland “is a worldwide phenomenon,” says Peter Verburg, a researcher on land use at the Free University Amsterdam. Small-scale farmers with rocky soil, steep hills, or scarce water “give up because they cannot compete,” Verburg says.

A century ago, farmers abandoned fields in upstate New York and parts of New England. Much of that land is now covered in forests. In recent years, farmers have walked away from land in Eastern Europe, India, Kazakhstan, Japan, and South Korea. By one estimate, the area of farm land that’s been abandoned around the world since 1950 could be as much as half of Australia.

Daskalova says it’s having a profound impact on ecosystems, but that isn’t getting the attention it deserves. “It’s happening out of sight, out of mind. That’s why so many people don’t even realize that abandonment is happening, because it’s out of their sight,” she says.

The familiar scenes of Daskalova’s childhood are now the subject of her ecological research. She’s now a research fellow at the University of Göttingen, in Germany, and she’s trying to figure out whether this phenomenon is an ecological tragedy or an opportunity.

“I really wanted to see, what does human migration mean for nature, for biodiversity?” Daskalova says. “And what are some of the ways that we could reimagine villages in a way that is good for both people and for nature?”

In dozens of Bulgarian villages, Daskalova and her colleagues are carrying out a regular census of plant species. They’ve hidden battery-powered audio recorders in trees to capture the sounds of birds and bats. Some of these villages, like Tyurkmen, are in Bulgaria’s more heavily populated lowlands, where abandoned fields lie next to others that still are cultivated. Others, in the mountains, are completely abandoned.

In Kreslyuvtsi, one of the completely abandoned “ghost villages,” ivy is climbing over empty houses, and wild blackberries fill what once were gardens or orchards. “As far as we can see, it’s just brambles,” Daskalova says.

According to Daskalova, when people left, a poorer version of nature took over. “The blackberries are suppressing the growth of anything else,” she says. Daskalova says the blackberries are suffocating the community of birds and plants that used to live here in gardens and orchards.

It illustrates why many European environmentalists want old-style farmers to stay in business; without people, cattle or sheep around, meadows filled with wildflowers and butterflies give way to shrubs and trees, which ecologists say are often less biologically diverse.

There’s increasing debate about that, though.

Henrique Pereira, a researcher with the German Centre for Integrative Biodiversity Research, first encountered land abandonment a couple of decades ago in his native Portugal. He was carrying out research in one of the country’s northern regions and he saw old-style cattle herding declining, and suddenly wild creatures like roe deer, ibex, and wild boar started to appear.

“I thought, ‘This is kind of a cool opportunity!’ ” Pereira says. He’s been pushing European officials to embrace that opportunity. When farming retreats, he says, it can open the way for landscapes that are wilder, free of human management, with space for creatures like wolves that farming once drove away.

There’s a name for this: Rewilding. An organization called Rewilding Europe is active in ten different regions where humans are moving out. They’re helping wildlife to move in.

Dan Charles is a contributing correspondent for Science Magazine. A print version of this story appeared there.