TEMPE, Ariz. – Arizona State University researchers have discovered for the first time that temperature determines where key soil microbes can thrive – microbes that are critical to forming topsoil crusts in arid lands. And of concern, the scientists predict that in as little as 50 years, global warming may push some of these microbes out of their present stronghold in colder U.S. deserts, with unknown consequences to soil fertility and erosion.

The findings are featured as the cover story of the June 28 edition of the journal Science.

An international research team led by Ferran Garcia-Pichel, microbiologist and professor with ASU’s School of Life Sciences, conducted continental-scale surveys of the microbial communities that live in soil crusts. The scientists collected crust samples from Oregon to New Mexico, and Utah to California and studied them by sequencing their microbial DNA.

While there are thousands of microbe species in just one pinch of crust, two cyanobacteria -bacteria capable of photosynthesis – were found to be the most common. Without cyanobacteria, the other microbes in the crust could not exist, as every other species depends on them for food and energy.

‘We wanted to know which microbes are where in the crust and whether they displayed […]