Data from: Allocation strategies for nitrogen and phosphorus in forest plants

The allocation of limiting elements, such as nitrogen (N) and phosphorus (P), in plants is an important basis for structural stability and functional optimization in natural plant communities. However, because of the lack of systematic investigation data, the mechanisms of optimal nutrient allocation in plants in natural forests are still unclear. Using consistent measurements of N and P contents in 930 plant species, we explored the allocation strategies for N and P in different plant organs and plant functional groups (PFGs) in natural communities. The N and P contents and N:P ratio were the highest in the leaf (the most active organ) at the organ level. At the PFG level, the N and P contents were higher in herbs than in woody plants, but the trend was opposite for the N:P ratio. The elemental plasticity of root was higher than that of leaf. Furthermore, at the large scale, the allometric exponents of N and P were less than 1 and showed no difference, indicating strong conservatism of the scaling relationship in plants. In summary, higher element content in more active organs, higher element plasticity in underground organs, and conservative allometric allocation among different organs and among different PFGs jointly constitute the optimal strategies for the allocation of limiting elements.植物体内限制性元素（如氮（N）、磷（P））的分配，是天然植物群落维持结构稳定与实现功能优化的重要基础。然而，由于缺乏系统调查数据，天然林中植物养分最优分配的机制仍未明确。本研究通过对930种植物的氮、磷含量开展统一测定，探究了天然群落中不同植物器官及植物功能群（plant functional groups, PFGs）的氮磷分配策略。在器官层面，作为活性最高的器官，叶片的氮、磷含量及氮磷比均处于最高水平。在植物功能群层面，草本植物的氮、磷含量高于木本植物，但氮磷比的变化趋势恰好相反。根系的元素可塑性高于叶片。进一步而言，在大尺度下，氮、磷的异速生长指数均小于1且无显著差异，表明植物的标度关系具有较强的保守性。综上，活性更高的器官具备更高的元素含量，地下器官拥有更强的元素可塑性，不同器官及不同植物功能群间均呈现保守的异速分配模式，三者共同构成了限制性元素分配的最优策略。