Many soil microbes play a vital role in ecosystems, as they help plants access nutrients and water and assist in stress tolerance such as during drought and to defend against pathogens. One such group of soil microbes are arbuscular mycorrhizal, aka AM, fungi, which are associated with the roots of approximately 70% of plant species on land.  new Dartmouth-led study reports on how global climate conditions affect AM fungal spore traits and the species biogeographic patterns. The results are published in the Proceedings of the National Academy of Sciences.