Forest types outpace constituent tree species in range shifts under global change

While geographic ranges of tree species worldwide are shifting under global changes, little is known about the range shift patterns of various types of forests as unique tree species ensembles. Here, using forest inventory data from 596,282 sample plots, we classified forested regions in North America into 43 forest types and quantified patterns of forest type range shifts over the past 50 years. Forest type ranges on average shifted 86.5 km·decade-1, more than three times as fast as the average of their constituent tree species (28.8 km·decade-1). This difference was attributable to a predominantly positive covariance between tree species ranges and the change of species relative abundance. These findings provide a timely scientific basis for a new paradigm of adaptive forest management and conservation.