Predicting microbial nutrient limitations from a stoichiometry-based threshold framework

Abstract

<p>While ecological stoichiometry-based theories and methodologies have been successfully applied to identify nutrient limitations in plankton and plants (e.g., leaf nutrient resorption ratios), determining nutrient limitations in soil microorganisms by them has great uncertainties. Establishing stoichiometric thresholds that define specific nutrient limitations for soil microbial communities has been a major challenge. Here, we present a threshold framework that predicts the limitations of carbon (C), nitrogen (N), and phosphorus (P) for microbial communities by leveraging the convergence of elemental stoichiometry from soils to microorganisms. Combined with a widely used model of microbial nutrient limitations (i.e., ecoenzyme vector model), the theoretical thresholds derived from this framework are validated by empirical thresholds identified through analysis of a comprehensive global dataset (<i>n</i> = 3277). Notably, we find that the commonly assumed threshold of 45�� in the ecoenzyme vector model overestimates microbial P limitation and underestimates microbial N limitation. By contrast, a vector length of 0.61 (unitless) and an angle of 55�� in the vector model are more reliable thresholds identifying microbial C and N/P limitations, respectively. This framework, with a fundamental understanding of microbially-driven stoichiometric convergence in plant-soil-microbe systems, offers a practical and general avenue for identifying microbial nutrient limitations in soils.</p>

Enzyme Activity Stoichiometry Suggests That Fertilization, Especially Nitrogen Fertilization, Alleviates Nutrient Limitation of Soil Microorganisms in Moso Bamboo Forests

“…Ecological stoichiometry theory posits that microbial metabolism necessitates the preservation of a balanced C, N, and P stoichiometry within an organism [64,65]. Disruptions in this stoichiometric equilibrium between microbes and their soil environment can prompt microbial responses [66,67]. These responses may include adjustments to the efficiency of elemental utilization of C, N, and P, alterations in the secretion of extracellular enzymes, or modifications in their elemental composition through shifts in community structure [68,69].…”

Regulation of soil organic carbon dynamics by microbial communities during reforestation of Chinese fir plantations after clear‐cutting

“…The relative C and P limitations for microbial communities play an essential role in nutrient cycling, especially for litter decomposition and SOC (Cui et al, 2021;Cui et al, 2024;Sinsabaugh et al, 2009).…”

“…The microbial limitation has been shown to vary strongly with stand age (Kang et al, 2022), and this alteration could be attributed to various content of available nutrients and demand for microorganisms for enzyme production (Cui et al, 2024). After clear-cutting an oak plantation in a moist temperate climate, microbial communities were limited by both C and P, but the limitation decreased with restoration age (Kang et al, 2022).…”