Bioavailability of Macro and Micronutrients Across Global Topsoils: Main Drivers and Global Change Impacts
Authors: Ochoa‐Hueso Raúl , Delgado‐Baquerizo Manuel , Risch Anita C. , Ashton Louise , Augustine David , Bélanger Nicolas , Bridgham Scott , Britton Andrea J. , Bruckman Viktor J. , Camarero J. Julio , Cornelissen Gerard , Crawford John A. , Dijkstra Feike A. , Diochon Amanda , Earl Stevan , Edgerley James , Epstein Howard , Felton Andrew , Fortier Julien , Gagnon Daniel , Greer Ken , Griffiths Hannah M. , Halde Caroline , Hanslin Hans Martin , Harris Lorna I. , Hartsock Jeremy A. , Hendrickson Paul , Hovstad Knut Anders , Hu Jia , Jani Arun D. , Kent Kelcy , Kerdraon‐Byrne Deirdre , Khalsa Sat Darshan S. , Lai Derrick Y. F. , Lambert France , LaMontagne Jalene M. , Lavergne Stéphanie , Lawrence Beth A. , Littke Kim , Leeper Abigail C. , Licht Mark A. , Liebig Mark A. , Lynn Joshua S. , Maclean Janet E. , Martinsen Vegard , McDaniel Marshall D. , McIntosh Anne C. S. , Miesel Jessica R. , Miller Jim , Mulvaney Michael J. , Moreno Gerardo , Newstead Laura , Pakeman Robin J. , Pergl Jan , Pinno Bradley D. , Piñeiro Juan , Quigley Kathleen , Radtke Troy M. , Reed Paul , Rolo Víctor , Rudgers Jennifer , Rutherford P. Michael , Sayer Emma J. , Serrano‐Grijalva Lilia , Strack Maria , Sukdeo Nicole , Taylor Andy F. S. , Truax Benoit , Tsuji Leonard J. S. , van Gestel Natasja , Vaness Brenda M. , Van Sundert Kevin , Vítková Michaela , Weigel Robert , Wilton Meaghan J. , Yano Yuriko , Teen Ewing , Bremer Eric 
Published: June 2023

Understanding the chemical composition of our planet's crust was one of the biggest questions of the 20th century. More than 100 years later, we are still far from understanding the global patterns in the bioavailability and spatial coupling of elements in topsoils worldwide, despite their importance for the productivity and functioning of terrestrial ecosystems. Here, we measured the bioavailability and coupling of thirteen macro‐ and micronutrients and phytotoxic elements in topsoils (3–8 cm) from a range of terrestrial ecosystems across all continents (∼10,000 observations) and in response to global change manipulations (∼5,000 observations). For this, we incubated between 1 and 4 pairs of anionic and cationic exchange membranes per site for a mean period of 53 days. The most bioavailable elements (Ca, Mg, and K) were also amongst the most abundant in the crust. Patterns of bioavailability were biome‐dependent and controlled by soil properties such as pH, organic matter content and texture, plant cover, and climate. However, global change simulations resulted in important alterations in the bioavailability of elements. Elements were highly coupled, and coupling was predictable by the atomic properties of elements, particularly mass, mass to charge ratio, and second ionization energy. Deviations from the predictable coupling‐atomic mass relationship were attributed to global change and agriculture. Our work illustrates the tight links between the bioavailability and coupling of topsoil elements and environmental context, human activities, and atomic properties of elements, thus deeply enhancing our integrated understanding of the biogeochemical connections that underlie the productivity and functioning of terrestrial ecosystems in a changing world.