Phosphorus additions have no impact on plant biomass or soil nitrogen in an alpine meadow on the Qinghai-Tibetan Plateau, China

Little is known about the effect of phosphorus (P) on plant biomass production or soil nitrogen (N) in alpine meadows. We conducted a four-year P addition experiment to assess the responses of plant biomass, plant N and P concentration, soil N availability, and microbial activities to a multi-level P enrichment (0, 2.5, 5, 10, 15 g P m(-2) year(-1)) in an alpine meadow on the Qinghai-Tibetan Plateau, China. The P treatments increased plant P and soil available P, but had no effect on plant biomass or plant N, soil available N, NH4+-N, NO3- -N, and soil microbial activity during three consecutive sampling years. These results suggest that P is not a limiting nutrient for plant growth and not a key factor on regulating N cycling in this alpine meadow. Further research is needed to identify the role of P in driving vegetation biomass production and soil N dynamics and clarify whether vegetation and soil characteristics on alpine meadows are sensitive to P enrichment. (C) 2016 Elsevier B.V. All rights reserved.