Even pathogens have their limits. When it gets too hot or too dry, some pathogens — like many living things — search for cooler, wetter and more hospitable climes. Ecologists have questioned if a warming, drying climate is connected to the spread of plant disease, but detecting a climate change fingerprint has been elusive.

A study from the University of California, Davis, provides some of the first evidence that climate change and drought are shifting the range of infectious disease in forests suffering from white pine blister rust disease.

“Because pathogens have thermal tolerances, we are seeing expansions and contractions in this disease’s range,” said lead author Joan Dudney, a Davis H. Smith postdoctoral fellow at UC Davis in the lab of Professor Andrew Latimer, a study co-author. “Climate change isn’t so much leading to widespread increases in this disease but rather shifting where it is emerging.”

The study, published today in the journal Nature Communications, found that white pine blister rust disease expanded its range into higher-elevation forests in the southern Sierra Nevada between 1996 and 2016. At the same time, it also contracted its range in lower elevations, where conditions were often too hot and dry for its survival.

Read more at: University of California - Davis

White pines dominate this high-elevation forest at Sequoia and Kings Canyon national parks. (Photo Credit: Joan Dudney/UC Davis)