Linking Changes in Plant Growth and Nutrient Stoichiometry With Nitrogen Enrichment in a Meadow Steppe

Abstract Exogenous nitrogen (N) inputs can significantly influence the availability of N and other nutrients in terrestrial ecosystems. However, the connections between soil nutrient dynamics following N enrichment and plant nutrient uptake as well as plant growth responses within a community remain underexplored. Here, we examined the effects of N addition on the dynamics of several macro and micronutrients in soil and three dominant plants on a meadow steppe in China. The results showed that (a) the exchangeable Ca and Mg in the soil initially increased when the N addition rate was lower than 10 g N m −2 yr −1 and then decreased at higher N addition rates (10–50 g N m −2 yr −1 ), whereas the available P and extractable Fe, Mn, and Cu remained relatively stable at low N addition rates but increased at high N addition rates. (b) The response of plant nutrient concentrations and the stoichiometry of these nutrients to N addition was not only species‐specific but also showed marked differences especially for those micronutrients. (c) Species with lower variation in nutrient concentrations, such as Leymus chinensis ( Lc ) and Thermopsis lanceolata ( Tl ), exhibited increased (for Lc ) or stable (for Tl ) biomass after N addition, whereas species such as Carex duriuscula , with greater nutrient variability, experienced reduced biomass. These findings suggest that soil acidification induced by exogenous N inputs alters soil nutrient availability and further results in imbalanced plant nutrient uptake and stoichiometries, which will affect the dynamics and structures of plant communities under global change scenarios.