Unearthing the soil‐borne microbiome of land plants
Raúl Ochoa‐Hueso, David J. Eldridge, Miguel Berdugo, Pankaj Trivedi, Blessing Sokoya, Concha Cano‐Díaz, Sebastián Abades, Fernando D. Alfaro, Adebola R. Bamigboye, Felipe Bastida, José Luis Blanco‐Pastor, Asunción de los Rı́os, Jorge Durán, Stefan Geisen, Tine Grebenc, Javier Gutiérrez Illán, Yu‐Rong Liu, Thulani P. Makhalanyane, Steven D. Mamet, Marco A. Molina‐Montenegro, José L. Moreno, Tina Unuk Nahberger, Gabriel F. Peñaloza‐Bojacá, César Plaza, Ana Rey, Alexandra Rodríguez, Christina Siebe, Brajesh K. Singh, Alberto L. Teixido, Cristian Torres‐Díaz, Ling Wang, Jianyong Wang, Juntao Wang, Eli Zaady, Xiaobing Zhou, Xinquan Zhou, Leho Tedersoo, Manuel Delgado‐Baquerizo
Abstract
Abstract Plant–soil biodiversity interactions are fundamental for the functioning of terrestrial ecosystems. Yet, the existence of a set of globally distributed topsoil microbial and small invertebrate organisms consistently associated with land plants (i.e., their consistent soil‐borne microbiome), together with the environmental preferences and functional capabilities of these organisms, remains unknown. We conducted a standardized field survey under 150 species of land plants, including 58 species of bryophytes and 92 of vascular plants, across 124 locations from all continents. We found that, despite the immense biodiversity of soil organisms, the land plants evaluated only shared a small fraction (less than 1%) of all microbial and invertebrate taxa that were present across contrasting climatic and soil conditions and vegetation types. These consistent taxa were dominated by generalist decomposers and phagotrophs and their presence was positively correlated with the abundance of functional genes linked to mineralization. Finally, we showed that crossing environmental thresholds in aridity (aridity index of 0.65, i.e., the transition from mesic to dry ecosystems), soil pH (5.5; i.e., the transition from acidic to strongly acidic soils), and carbon (less than 2%, the lower limit of fertile soils) can result in drastic disruptions in the associations between land plants and soil organisms, with potential implications for the delivery of soil ecosystem processes under ongoing global environmental change.