The Pennsylvania landscape has undergone a near-complete transformation over the last 350 years, starting with the extirpation of the Lenape and the loss of their fire management practices. After European settlement, extensive logging and land clearing, the introduction of exotic insects, diseases and invasive plants, increasing deer browsing, and the Smokey Bear-era has led to unprecedented changes in forest composition across the eastern US. We’ve lost not only once-dominant chestnut trees, but many white pine forests too, and super-abundant white oak is in decline. Oaks, hickories, and pines are not regenerating, red maples are on the rise-- and the climate is changing. Marc D. Abrams, Ph. D., professor of forest ecology at Penn State, explains the sweeping history of our once and future forests.