The Overlapping Plagues Quietly Devastating American Forests

The Overlapping Plagues Quietly Devastating American Forests The trees are sick. Epidemics are escalating, across numerous species, as more and more pests and pathogens invade forests. Their entryway is global trade — in live plants, and in the countless products that are shipped in wooden pallets, crates and other packaging. As trade has boomed, so have the opportunities for tiny stowaways to wreak havoc. “We’re moving insects and microbes around the world through trade very rapidly, and basically running an experiment” to see which ones will take hold, said Bernard Slippers, a forest pathologist at the University of Pretoria in South Africa. The attackers have killed billions of trees already, with countless more under threat. In some severe cases, forests are transforming into bleak spaces of brambles and vines. And the impact extends far beyond the woods. Trees filter water, stabilize the land and clean the air. They absorb and store planet-warming carbon dioxide, fighting climate change. They create the three-dimensional habitat that countless species use for shelter and shade. And they offer something even more foundational. “Plants are the only thing that take sunlight, carbon dioxide, water, and turn it into biological energy,” said Anurag Agrawal, an ecologist at Cornell University. “Plants, trees are the ultimate source for all of the energy, all of the food on the planet.” Emerald ash borer larvae; a healthy hemlock in the Mohonk Preserve; ash borer eggs. Credit... Maddie McGarvey for The New York Times; Bryan Anselm for The New York Times; Maddie McGarvey for The New York Times We are having trouble retrieving the article content. Please enable JavaScript in your browser settings. Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times. Thank you for your patience while we verify access. Already a subscriber? Log in . Want all of The Times? Subscribe .