In arid regions, the microbes that power threatened dryland soil ecosystems called biological soil crusts stay dormant over long periods, only "awakening" when they sense moisture from infrequent rainfall. Now, a team led by researchers at Penn State—driven by projections that those biocrusts will decline by as much as 40% in the next 45 years—found that when a dryland soil does get wet, most of the microbes in the biocrust stay inactive. It's a discovery that will inform ongoing efforts to conserve and restore biocrusts, according to the researchers.