New study predicts Mexican tree species could become future forests of USA and Canada

As global temperatures rise, many tree species that now grow mainly in Mexico may find a suitable climate farther north in the United States and Canada by the end of this century, according to a new study published in Forest Ecosystems.

The research analyzed how climate change could affect the future distribution of tree species across North America. It examined 442 species in total: 184 species that already grow across Mexico, the U.S. and Canada, and 258 species that are mainly found in Mexico, including 51 species unique to that country.

The study found that a suitable climate for many species is likely to shift hundreds of kilometers northward. On average, projected shifts ranged from about 200 to more than 600 kilometers, depending on how much warming occurs.

For species that already grow across borders, losses of suitable climate were mainly projected in parts of Mexico and along the USA Gulf Coast. At the same time, new suitable areas appeared in the western United States and Canada. For species mostly concentrated in Mexico, a suitable climate was projected to decrease south of Mexico but expand in northern Mexico, the southeastern United States, and along the Pacific coast up into Canada. Despite these shifts, most Mexican tree species were still predicted to retain some suitable climate within Mexico in the future, even if their main growing areas move.

The models showed that many Mexican tree species already have a suitable climate in parts of the United States and Canada today, even though they are not commonly found there, which suggests a lag in ecosystem transition.

“Climate change does not care about political boundaries, and neither will tree species,” said the author Brice Hanberry of the U.S. Forest Service. “Many species already have suitable climates farther north, even if they are not present there yet. This suggests ecosystems are lagging behind climate change, and management can act now to prepare for whatis coming.”

Species with large geographic ranges and those growing at lower elevations were more likely to gain new suitable areas. In contrast, species unique to restricted habitats or at high elevations were more likely to lose suitable climate.

Overall, climate change could reshape forests across Mexico, the United States and Canada over the coming decades. While many species may persist, their locations and abundance could change substantially. Rather than sudden transformations, the results point to gradual shifts in which tree species dominate different regions. How forests respond will depend not only on climate but also on land management and conservation decisions made in the coming years.