Cornell is at the forefront of determining how "invisibility cloaks" and walls of protection may give ash trees hope of revival.

There’s a tree killer on the loose in Oregon, and nobody knows how to stop it. An invasive green beetle called the emerald ash borer arrived in the Midwest from Asia, and it’s killed over 100 million ...

In 2006, Kathleen Knight was walking through a forest in northwest Ohio. She's a researched ecologist with the U.S. Forest Service. All around her were big, beautiful ash trees, tall trunks with lush ...

James E. Zablotny/USDA APHIS This week, crews removed dozens of infested ash trees in Forest Grove as part of a state plan to slow the spread of the destructive pest. This month, state agencies ...

After more than a half-century in which disease and invasive species robbed Detroit of much of its tree population, officials are investing millions in making the city greener. Over the next three ...