A new study has revealed that abandoned cropland is often quickly recultivated, preventing habit restoration and carbon sequestration on the land, highly desired environmental benefits that naturalists and scientists often hope for from rural agricultural land.

“As people move from rural areas into cities, there is a chance for wildlife and the climate to gain ground — literally — as abandoned farms and pastures revert back to forests and grasslands,” said study co-author David Wilcove, professor of ecology and evolutionary biology and public affairs at Princeton University. “Our work shows that this is not happening because the ‘abandoned’ lands are being rapidly recultivated.”

After studying 11 sites across four continents, the researchers found that, on average, recultivation occurred after only 14 years. This is not long enough to offset substantial amounts of carbon, or become high-quality habitat for wildlife, the researchers said. They also found that within 30 years, their models predict that around 50% of abandoned croplands will be recultivated.

“Without incentives for restoration, cropland abandonment rarely lasts long enough to yield benefits for biodiversity or carbon sequestration,” said lead author Christopher Crawford, a Ph.D. candidate at Princeton’s School of Public and International Affairs. “For abandoned croplands to reach levels of carbon stocks and biodiversity comparable to more intact natural ecosystems, they typically need at least 50 years of regeneration.”