Grow again, not reuse: how restoring abandoned farms can mitigate climate change
Around the world, millions of acres of land are being abandoned due to what is known as “rural migration”, or people moving to urban centres. Some people go out in search of economic prosperity. Others are forced to move out because of conflict or the effects of climate change. Along with globalization and mechanization, these population changes are changing the economics of farming in these areas, leaving less productive land.
Some of these croplands eventually regenerate into natural habitats, helping to increase biodiversity and absorb atmospheric carbon. While environmentalists have been optimistic for this process to provide opportunities to restore habitat and sequester carbon, this is unlikely to happen without policy intervention, according to a new study. science progressWhich shows that most of the land is eventually cultivated.
Study co-author David Wilcove said, “As people move from rural areas to cities, wildlife and climate have a chance to gain land – literally – by returning abandoned fields and pastures back to forests and grasslands. take me back.” Evolutionary Biology and Public Affairs and High Meadows Environment Institute (HMEI). “Our work shows that this is not happening because ‘abandoned’ land is increasingly being cultivated.”
“Unless countries and policymakers develop better regulations and incentives to allow these lands to recover, this opportunity to restore ecosystems will not be fully realized,” said lead author Christopher Crawford Said, a Ph.D. candidate at SPIA mentored by Wilkov and an alumnus of the Princeton Energy and Climate Scholars Program at HMEI. “It will be a missed opportunity to fight climate change and biodiversity loss.”
Crawford and Wilcove are both affiliated with the Center for Policy Research on Energy and the Environment, which is based at the Princeton School of Public and International Affairs. The study is the first in a series of papers focused on the effects of cropland abandonment on carbon and biodiversity, led by Crawford’s Ph.D. acts as the heart. essay. Study co-authors include He Yin of Kent State University and Volker C. of the University of Wisconsin-Madison. Radeloff included.
To see where the cropland was being regenerated—and how long the process lasted—the researchers used state-of-the-art annual land-cover maps developed from satellite imagery covering 1987 to 2017. Abandonment and recurrence were estimated by tracking individual parcels of cropland over time.
The research team studied images from 11 sites across four continents, including locations in the United States, Brazil, Bosnia and Herzegovina, China, Iraq, Kazakhstan, Belarus and Russia. In these areas, crop land was abandoned for reasons ranging from war and conflict to socioeconomic and environmental factors.
Some sites were located in the former Soviet Union and were abandoned after the geopolitical turmoil of the collapse of the Union. Meanwhile, China has active afforestation programs that encourage redevelopment of forests on marginal agricultural lands and is experiencing an increasing amount of rural migration, like the other countries involved in the study.
The extent to which cropland abandonment provides environmental opportunities depends on how much is left and how long it lasts. Unfortunately, after tracking the abandonment from year to year, the researchers found that a substantial amount of the land they studied was eventually cultivated.
Although this varied across sites, the land experienced the highest level of cultivation in the former Soviet Union. Meanwhile, in China’s Shaanxi and Shanxi provinces, land was briefly abandoned, perhaps thanks to the central government’s “Grain for Green Programme”, which provides financial incentives for the harvest.
Overall, most of the croplands reviewed in the study were left abandoned for an average of only 14 years, which is not enough to offset a substantial amount of carbon or become high-quality habitat for wildlife, the researchers said. Within 30 years, their models predict that about 50% of the abandoned crop land will be cultivated. In the process, significant environmental benefits will be lost. Cultivation of abandoned crop land at these sites resulted in more than 30% less area abandoned and 35% less carbon acquired by 2017.
“Without incentives for restoration, cropland abandonment rarely lasts long enough to yield benefits for biodiversity or carbon sequestration,” Crawford said. “Compared to more intact natural ecosystems for abandoned croplands to reach carbon stock and biodiversity levels, they typically require at least 50 years of regeneration.”
However, the findings from Shaanxi and Shanxi provinces provide evidence that incentive programs can be successful. The researchers also proposed that abandoned farms, especially on crop land that is not essential for food production, should be converted into protected areas. Ecosystem service programs can provide payment to landowners for leaving their crop land. Or steps may be taken to support sustainable long-term farming of some sites so that farms have less turnover.
