Spatial preemption-based mechanisms explain aboveground biomass of Potentilla bifurca in response to nitrogen addition in a temperate grassland community - Liuyi Yang; Huiqiu Shi; Lulu Zhang; Yuting Li; Liang Gao; Qiang Yu; Changliang Shao; Honghui Wu; Wen-Hao Zhang (Plant and Soil, 2026)