生态化学计量学是研究生物有机体的化学元素组成和生态系统能量平衡的科学。氮和磷是植物生长发育所必需的两种关键元素，这两种元素的含量之间存在怎样的计量关系？这种关系在不同生活型和不同地区的植物之间是否变化？植物氮和磷元素含量之间的计量关系，与植物生长和功能属性间有何内在关联？全球变化是否会改变植物原有的氮磷计量关系？这些都是植物氮磷计量学所要研究的主要问题。文章用简短的语言分别回答

Ecological stoichiometry mainly focuses on the quantitative relationships of organismal component elements and energy dynamic equilibrium across trophic levels in ecosystems. Nitrogen (N) and phosphorus (P) are essential elements for plant growth. What is the quantitative relationship between these two elements? Does the relationship between N and P vary among different plant life forms and different eco-regions? Are there intrinsic correlations between plant N and P stoichiometric patterns and its growth and functional properties? Can global changes influence the inherent N and P stoichiometry of plants? Answering these questions is major research themes of plant stoichiometry. In this paper we make a brief introduction on these questions.