Effects of Combined Nitrogen–Phosphorus on Biomass Accumulation, Allocation, and Allometric Growth Relationships in <i>Pinus yunnanensis</i> Seedlings after Top Pruning oleh Guangpeng Tang, Yu Wang, Zhuangyue Lu, Sili Cheng, Zhaoliu Hu, Shi Chen, Lin Chen, Junrong Tang, Yulan Xu, Nianhui Cai