Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (7): 682-713.DOI: 10.17521/cjpe.2020.0331

Special Issue: 生态化学计量

• Hou Xueyu Review • Previous Articles     Next Articles

Review on characteristics and main hypotheses of plant ecological stoichiometry

TIAN Di1(), YAN Zheng-Bing2, FANG Jing-Yun3,**()   

  1. 1The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing 100083, China
    2School of Biological Sciences, The University of Hong Kong, Hong Kong, China
    3Institute of Ecology, Key Laboratory for Earth Surface Processes of the Ministry of Education, and College of Urban and Environmental Science, Peking University, Beijing 100871, China
  • Received:2020-10-10 Accepted:2021-01-07 Online:2021-07-20 Published:2021-10-22
  • Contact: ** FANG Jing-Yun jyfang@urban.pku.edu.cn
  • Supported by:
    National Natural Science Foundation of China(31800397);National Natural Science Foundation of China(31901086);National Natural Science Foundation of China(31988102)

Abstract:

Plant ecological stoichiometry, as a branch of ecological stoichiometry, focuses on the study of elemental content, ratios and relationships within and across plant organs, and the underlying biotic and abiotic drivers. In the 19th century, chemists detected the elemental contents in plant organs via laboratory experiments, sprouting the exploration of plant stoichiometric characteristics. Nowadays, ecologists have explored plant ecological stoichiometric characteristics and their responses to global changes and relationships with plant functional traits, using both field investigation and manipulative experiments. These sustained efforts have largely enriched the knowledge and understanding of plant ecological stoichiometry. In this paper, we briefly introduced the history and reviewed the research progresses of plant stoichiometry since the 19th century. Firstly, we proposed the developmental history of plant ecological stoichiometry as three main periods: sprouting, hypothesis foundation, and theoretical construction periods, and introduced some representative works for each period. Secondly, we overviewed plant ecological stoichiometric characteristics across organs, life forms and environmental gradients. The geometric mean values of leaf nitrogen (N) and phosphorus (P) contents and N:P mass ratios in global terrestrial plants are 18.74 mg∙g-1, 1.21 mg∙g-1 and 15.55 (i.e. similar to the Redfield ratio of 16:1), respectively. Leaf N and P contents at either species or community level generally show a decreasing trend with increasing temperature and precipitation, and have large variations among life forms, with higher values in herbaceous than woody plants, and deciduous broad-leaved than evergreen broad-leaved and coniferous woody plants. Compared with leaves, the stoichiometric characteristics of fine roots and other organs in plants remain poorly documented. Thirdly, we reviewed the effects of nutrient addition on plant ecological stoichiometric characteristics. In general, N addition increases soil N availability, then the N content and N:P in plants, thus leading to an increase in plant productivity to some extents. P addition might alleviate the N and P imbalance induced by excessive N inputs, and then increase plant P content. However, long-term nutrient fertilization could perturb the intrinsic stoichiometric characteristics in plants, resulting in the deteriorated nutrient imbalance in tissues and then the subsequent decline in plant productivity. Fourthly, we introduced the main hypotheses of plant ecological stoichiometry. These hypotheses include function-associated hypotheses, environment-associated hypotheses and evolution-associated hypotheses, which delineate the relationships of stoichiometric characteristics with plant growth functions, environmental factors and plant evolutionary history, respectively. Finally, we made an outlook on future research in the area of plant ecological stoichiometry, and highlighted ten potential and important research themes.

Key words: stoichiometry, nitrogen, phosphorus, ecology, plant, hypothesis, brief history