For thousands of years, one tree species defined the cultural and ecological identity of what is now the American South: the longleaf pine. The forest once stretched across 92 million acres from Virginia to Texas, but about 5% of that original forest remains. It was one of North America’s richest ecosystems, and it nearly disappeared.

From the Griswolds to the Grinch, just about every holiday movie features characters cutting, decorating or stealing the perfect Christmas tree. But most people—including moviegoers—don’t consider that Christmas trees take work to cultivate. Like all trees, they are subject to the threats of disease, insects, fungi and other menaces. This is why scientists in Mississippi State’s Forest and Wildlife Research Center have been studying some of the most popular tree species that decorate homes for the holidays.