Virginia has lost more forestland over the past few decades than most other states, according to a new report from Massachusetts-based Clark University.
The School of Climate, Environment and Society on Thursday released a study documenting the issue nationwide between 1990 and 2017.
It found that across the U.S., about 10 million acres of forest were lost to development or converted to cropland.
“It equates to losing a football field every two minutes for 28 years,” said Chris Williams, a professor of geography and environmental science at Clark University.
A majority of those losses were concentrated in the Southeast. Virginia and 10 other states in the region accounted for about 70% of the nation’s total lost forest.
Williams said researchers were surprised just how much forestland is going toward expansion of farmland.
“New development of cropland has been eating away, chipping away at forests,” he said. “That, plus development, we're seeing a lot of that spatially concentrated in the southeastern U.S. states from Texas to Virginia.”
In Virginia, 61% of the lost forestland was converted to cropland, with the remaining 39% developed. In total, the Commonwealth lost about 494,000 acres, the seventh-most in the country.
The nation’s top three counties for forest loss were in Virginia: Pittsylvania, Chesterfield and Prince William. Norfolk was also a hotspot.
Williams said researchers focused on forests they consider lost permanently, versus areas cleared for regrowth such as in the timber industry.
Developed land rarely returns to nature, he said. Plus, fully restoring a forest would take centuries.
“We're fixated on permanent forest loss because you lose mature forest or present-day forest forever,” he said. “That has a bigger climate impact, and it causes greater erosion of the ecosystem services we enjoy from our forestlands.”
The data comes from satellite imagery at the scale of a quarter of an acre. To be considered forested, the area would have at least 20% tree cover. Those billions of pixels were then matched with federal data about land cover and use.
The report also looked at the corresponding “climate burden” of forest losses.
Forests act as “carbon sinks” because trees absorb and store carbon dioxide. When trees are removed, that carbon is released into the atmosphere, contributing to global warming.
Researchers calculated that about 2.3 billion tons of carbon dioxide were emitted across the mainland U.S. over the studied time period because of forest loss.
That’s equivalent to about 1% of the nation’s total carbon emissions.
“It’s not a major wedge if you’re thinking about climate mitigation, but it’s still a meaningful contribution and one that deserves some attention,” Williams said. “It's not just in the Amazon or in Indonesia. It’s also here in the U.S.”
Overall, the land changes have happened relatively steadily over the 28 years, he said.
Researchers don’t know exactly why the Southeast figures so disproportionately. Williams suspects increased migration to the South could play a role.
“I think it's fair to say that the opportunity to build and develop land is different, and maybe there's more opportunity to do that freely in the South and Southeast,” he said. “There's also a favorable climate and set of conditions for expanding cropland and new pressures and interests in doing so.”
Clark University is part of a coalition called the Forest Carbon Data Partnership that is finalizing a U.S. Forest Monitor tool to display continuous information on forest loss.
