West Virginia’s wildlands are a “canary in the coal mine for climate change” because of the forests’ biodiversity, which, along with rich soils and abundant rainfall, make them among the strongest forests globally, according to Brenden McNeil, an associate professor of geography at WVU’s Eberly College of Arts and Sciences. The state’s forests have been resilient to a barrage of logging and acid rain in the 19th and 20th centuries but are now exhibiting symptoms of declining health because of climate change.
Trees, like humans, need to have more than one thing in their diets, McNeil said. And the proliferation of carbon dioxide is force-feeding them the one thing they use most. McNeil said the challenge is to restore a balanced diet for forests by severely cutting back or ending altogether the use of fossil fuels.
“There’s more carbon dioxide in the atmosphere, and that’s the raw material that trees need to convert to sugar, which they use to grow,” he said. “What is profound is that as all the plants grow faster; they’re slowing down climate change.” But, as he explained, “the plants of the world can’t do that forever.”
In a paper published in Nature Ecology and Evolution, McNeil and nearly 40 international researchers suggest that most terrestrial ecosystems are seeing declining nitrogen isotopes in foliage on a global scale. It adds global support to a 2017 paper where McNeil was part of another team that used nitrogen isotopes in tree rings to find evidence for declining nitrogen in forests across the United States. Most of the world is still “greening” in response to climate change, but diminishing nitrogen means future growth will become unhealthier and out of balance, and trees will need to work harder to extract the nitrogen, McNeil continued.