Boreal forest in Siberia

Until recently, the northern part of the Great Russian forest—which is the size of the continental U.S.—was populated with larch trees, while the slightly warmer southern part was populated by evergreen conifers. UVA environmental sciences researchers say that now evergreen conifers are encroaching on the larch-dominated boreal forest due to global warming. Unlike larch trees, evergreen conifers, such as spruce and fir, retain their needles year-round and absorb sunlight, which will make the forest even warmer. “What we’re seeing is a system kicking into overdrive,” says Hank Shugart, a professor of environmental sciences. “Warming creates more warming.”