Soil moisture and texture primarily control the soil nutrient stoichiometry across the Tibetan grassland

Abstract Soil nutrient stoichiometryand its environmental controllers play vital roles in understanding soil-plant interaction and nutrient cyclingunder a changing environment, while they remain poorly understood in alpine grasslanddue to lack of systematic field investigations. We examined the patterns and controls of soil nutrients stoichiometryfor the top 10 cm soils across the Tibetan ecosystems. Soil nutrient stoichiometryvaried substantially among vegetation types. Alpine swamp meadow had larger topsoilC:N, C:P, N:P, and C:K ratios compared to the alpine meadow, alpine steppe, and alpine desert. In addition, the presence or absence of permafrost did not significantly impact soil nutrient stoichiometryin Tibetan grassland. Moreover, clay and silt contents explained approximately 32.5% of the total variation in soil C:N ratio. Climate, topography, soil properties, and vegetation combined to explain 10.3–13.2% for the stoichiometryof soil C:P, N:P, and C:K. Furthermore, soil C and N were weakly related to P and K in alpine grassland. These results indicated that the nutrientlimitation in alpine ecosystem might shifts from N-limited to P-limited or K-limited due to the increase of N deposition and decrease of soil P and K contents under the changing climate conditions and weathering stages. Finally, we suggested that soil moisture and mud content could be good predictors of topsoil nutrient stoichiometryin Tibetan grassland.