U.S. Forest Service

    Imagine a young red oak growing in an open meadow, its limbs reaching towards the bright October sky. As fall sets in, its broad leaves are turning a scarlet hue. But this iconic tree isn’t growing in a New Jersey park or hardwood forest in Vermont. Rather, it stands conspicuously in a lush garden just outside of Nanjing, China. A growing network of gardens in East Asia, Europe, and the US cultivate tree species native to other parts of the world. These so-called “sentinel gardens” are more than just collections of exotic plants. They stand as the first line of defense for forests and may just uncover the next dangerous invasive pest or pathogen—the ones that haven’t yet arrived. Funding Sentinel Gardens “These trees are like a canary in a coal mine,” said Isabel Munck, plant pathologist with the Forest Service’s Northeastern Area field office. “They are out ahead of the threat and are providing us with important information about potential invasive species.” Invasive species of insects and fungi know no boundaries or borders. They devastate individual trees and large swaths of forests. As a result, the Forest Service is now partnering with research institutions in the US and abroad to grow sentinel gardens. It now funds and supports nine gardens on three continents: Asia, Europe, and North America. “Europeans have been using this approach to identify potential invasive species for some time,” said Beth Lebow, invasive species program coordinator for the Forest Service’s International Programs. “When we ...