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New data on more than 1,500 trees in nearly 1,000 locations suggests that an existing theory about how individuals within a species will respond to a changing climate may not be correct.

The data, in the form of pine tree rings from land, contradicts the assumptions underlying the climate envelope projection, which uses a set of climate conditions or “envelope” that a species can live under to predict how it will respond to change of the climate.

When looking at temperature, individuals of a species in the coolest zone – known as the “leading edge” – are predicted to benefit from warming, while those in the warmer zone or “trailing edge” will suffer. If this is true, the geographic distribution of species can track a changing climate.

In examining tree-ring data, Research—Published Proceedings of the National Academy of Sciences and conducted by Margaret Evans and her team at the University of Arizona—found that the trailing edge spanned the entire geographic distribution of the common piñon, a tree endemic to the Colorado Plateau.

Instead of half the distribution benefiting from warming, all trees in all sample sites suffered from warming. Without evolutionary change in individual-scale climate tolerance, the common piñon faces the risk of extinction as the climate warms.

Evans shares first authorship of the paper with a former postdoctoral fellow in her lab, Kelly Heilman, and Sharmila Day, who first came to the lab as a high school volunteer and is now an undergraduate at Harvard University.