Recently, Nature Communications published a research paper titled "Environmental versus Phylogenetic Controls on Leaf Nitrogen and Phosphorus Concentrations in Vascular Plants" by Tian Di, a young teacher from the College of Forestry, and his collaborators. This study represents significant progress in understanding the driving mechanisms behind macro-scale patterns of nitrogen and phosphorus concentrations in vascular plants. The State Key Laboratory of Efficient Production of Forest Resources at Beijing Forestry University is the signature unit of the first author.

Global patterns of leaf nitrogen (N) and phosphorus (P) stoichiometry have been interpreted as reflecting phenotypic plasticity in response to the environment, or as an overriding effect of the distribution of species growing in their biogeochemical niches. Here, we balance these contrasting views. We compile a global dataset of 36,413 paired observations of leaf N and P concentrations, taxonomy and 45 environmental covariates, covering 7,549 sites and 3,700 species, to investigate how species identity and environmental variables control variations in mass-based leaf N and P concentrations, and the N:P ratio. We find within-species variation contributes around half of the total variation, with 29%, 31%, and 22% of leaf N, P, and N:P variation, respectively, explained by environmental variables. Within-species plasticity along environmental gradients varies across species and is highest for leaf N:P and lowest for leaf N. We identified effects of environmental variables on within-species variation using random forest models, whereas effects were largely missed by widely used linear mixed-effect models. Our analysis demonstrates a substantial influence of the environment in driving plastic responses of leaf N, P, and N:P within species, which challenges reports of a fixed biogeochemical niche and the overriding importance of species distributions in shaping global patterns of leaf N and P.

Benjamin Stocker from the University of Bern is a co-responding author on the paper, and this research was supported by the National Key R&D Program of China (No. 2022YFD2201600), grants from the National Natural Science Foundation of China (32271680; 31800397; and 31901086), and the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA26050401). Tian Di received support from the Swiss Government Excellence Scholarship (2020-2021), the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology (2021-2023, No. 2021QNRC001), and the Double First-Class University Project Research & Innovation Team Project of Beijing Forestry University (No: BLRC2023A01).

Paper link: https://www.nature.com/articles/s41467-024-49665-4

Written by Zhang Naili
Translated and edited by Song He
Reviewed by Yu Yangyang