Mycorrhizal ecology would benefit from region-specific hypotheses

Most arbuscular mycorrhizal fungi exhibit global distributions but have been studied mostly in a specific region of the globe, mainly covering temperate and boreal habitats, where nitrogen is the most common nutrient limiting primary productivity. Yet, it is relatively common to extrapolate our understanding of temperate and boreal systems to other regions of the globe. While the physiology of mycorrhizal associations is unlikely to differ worldwide, there are good chances that environmental settings interact with the way mycorrhizas function across ecoregions. Here, we first argue that mycorrhizal ecologists should develop region-specific hypotheses. We subsequently identify likely differences in how mycorrhizas function in subtropical regions compared with better-studied temperate and boreal areas. We finally use the subtropical region of China to develop five geographically-focused hypotheses, envisaging that they will trigger the interest of the scientific community worldwide in understudied regions into studying mycorrhizas through a new lens. Expanding the range of hypotheses in mycorrhizal ecology to describe understudied regions of the world, has the potential to confer multifaceted benefits to both science and society. We advocate to do so, and present a roadmap on how to develop such hypotheses.