J Plant Ecol ›› 2021, Vol. 14 ›› Issue (3): 361-371.DOI: 10.1093/jpe/rtaa100

• Research Articles •     Next Articles

Nitrogen addition affects plant biomass allocation but not allometric relationships among different organs across the globe

Kai Yue1, Dario A. Fornara2, Wang Li3, Xiangyin Ni1, Yan Peng1,4, Shu Liao1, Siyi Tan1, Dingyi Wang1, Fuzhong Wu1, *, and Yusheng Yang1   

  1. 1 Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China, 2 Sustainable Agri-Food Science Division, Agri-Food and Bioscience Institute (AFBI), Belfast, UK, 3 State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China, 4 Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, DK-1958 Frederiksberg C, Denmark

    *Corresponding author. E-mail: wufzchina@163.com
  • Received:2020-04-29 Revised:2020-07-16 Accepted:2020-11-25 Online:2020-12-18 Published:2021-06-01



Biomass allocation to different organs is a fundamental plant ecophysiological process to better respond to changing environments; yet, it remains poorly understood how patterns of biomass allocation respond to nitrogen (N) additions across terrestrial ecosystems worldwide.


We conducted a meta-analysis using 5474 pairwise observations from 333 articles to assess how N addition affected plant biomass and biomass allocation among different organs. We also tested the ‘ratio-based optimal partitioning’ vs. the ‘isometric allocation’ hypotheses to explain potential N addition effects on biomass allocation.

Important Findings

We found that (i) N addition significantly increased whole plant biomass and the biomass of different organs, but decreased root:shoot ratio (RS) and root mass fraction (RMF) while no effects of N addition on leaf mass fraction and stem mass fraction at the global scale; (ii) the effects of N addition on ratio-based biomass allocation were mediated by individual or interactive effects of moderator variables such as experimental conditions, plant functional types, latitudes and rates of N addition and (iii) N addition did not affect allometric relationships among different organs, suggesting that decreases in RS and RMF may result from isometric allocation patterns following increases in whole plant biomass. Despite alteration of ratio-based biomass allocation between root and shoot by N addition, the unaffected allometric scaling relationships among different organs (including root vs. shoot) suggest that plant biomass allocation patterns are more appropriately explained by the isometric allocation hypothesis rather than the optimal partitioning hypothesis. Our findings contribute to better understand N-induced effects on allometric relationships of terrestrial plants, and suggest that these ecophysiological responses should be incorporated into models that aim to predict how terrestrial ecosystems may respond to enhanced N deposition under future global change scenarios.

Key words: meta-analysis, allometry, biomass fraction, ecosystem, plant functional type, global


关键词: 整合分析, 异速生长, 质量分数, 生态系统, 植物功能性状, 全球尺度