Soil element coupling is driven by ecological context and atomic mass

• Published in: Ecology letters 2021-02, Vol.24 (2), p.319-326
• Main Authors: Ochoa‐Hueso, Raúl, Plaza, César, Moreno‐Jiménez, Eduardo, Delgado‐Baquerizo, Manuel, Peñuelas, Josep
• Format: Article
• Language: English
• Subjects: Atomic properties; Biodiversity; biotic controllers; Carbon; chronosequences; coupled biogeochemical cycles; Coupling; Ecosystem; elemental cycles; Microorganisms; Nitrogen - analysis; Organic matter; pedogenesis; Phosphorus; Soil; Soil chemistry; Soil Microbiology; Soil pH; Soil structure; Soils; Terrestrial environments; Topsoil
• ISSN: 1461-023X; 1461-0248
• DOI: 10.1111/ele.13648

The biogeochemical cycling of multiple soil elements is fundamental for life on Earth. Here, we conducted a global field survey across 16 chronosequences from contrasting biomes with soil ages ranging from centuries to millions of years. For this, we collected and analysed 435 topsoil samples (0–10 cm) from 87 locations. We showed that high levels of topsoil element coupling, defined as the average correlation among nineteen soil elements, are maintained over geological timescales globally. Cross‐biome changes in plant biodiversity, soil microbial structure, weathering, soil pH and texture, and mineral‐free unprotected organic matter content largely controlled multi‐element coupling. Moreover, elements with heavier atomic mass were naturally more decoupled and unpredictable in space than those with lighter mass. Only the coupling of carbon, nitrogen and phosphorus, which are essential to life on Earth, deviated from this predictable pattern, suggesting that this anomaly may be an undeniable fingerprint of life in terrestrial soils. The biogeochemical cycling of multiple soil elements is fundamental for life on Earth. We showed that high levels of topsoil element coupling are maintained over geological timescales globally and that elements with heavier atomic mass were naturally more decoupled and unpredictable in space than those with lighter mass. Only the coupling of carbon, nitrogen and phosphorus, which are essential to life on Earth, deviated from this predictable pattern, suggesting that this anomaly may be an undeniable fingerprint of life in terrestrial soils.