Chin J Plan Ecolo ›› 2015, Vol. 39 ›› Issue (8): 807-815.DOI: 10.17521/cjpe.2015.0077

Special Issue: 生态化学计量

• Orginal Article • Previous Articles     Next Articles

Relationships between plant stoichiometry and biomass in an arid-hot valley, Southwest China

YAN Bang-Guo1,2,3, LIU Gang-Cai2, FAN Bo1, HE Guang-Xiong1, SHI Liang-Tao1, LI Ji-Chao1,4, JI Zhong-Hua5,*()   

  1. 1Institute of Tropical Eco-agricultural Sciences, Yunnan Academy of Agricultural Sciences, Yuanmou, Yunnan 651300, China
    2Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Resources, Chengdu 610041, China
    3University of Chinese Academy of Sciences, Beijing, 100049, China
    4College of Agriculture, Guangxi University, Nanning 530004, China
    and 5Institute of Agricultural Environment and Resources, Yunnan Academy of Agricultural Sciences, Kunming 650205, China
  • Received:2015-03-17 Accepted:2015-06-10 Online:2015-08-01 Published:2015-08-17
  • Contact: Zhong-Hua JI
  • About author:

    # Co-first authors


Aims The micro-elemental stoichiometry as well as nitrogen (N) and phosphorus (P) plays an important role in ecosystem process. However, the drivers of the variations in these stoichiometric ratios in plants are less explored in compared with N and P. Plant productivity and plant stoichiometry can response simultaneously to environmental changes, such as water and nutrient supply levels. However, the relationships between the changes in plant stoichiometry and biomass were unclear yet although both of them play important roles in ecosystem functioning. Our object was to investigate the changes in plant stoichiometry (including multiple macro- and micro-elements) and in biomass under different nutrient and water supply. Methods We collected seeds from six grass species in an arid-hot valley and performed a nutrient-water addition experiment in 2012 with a complete factorial design (nutrient × water). The concentrations of N, P, K, Ca, Mg, Zn and Mn in different organs and plant biomass were measured. The effects of species, water and nutrient on element concentration and plant biomass were analyzed by three-way ANOVA. Linear regressions were used to test the relationships between changes in plant stoichiometry and changes in biomass after nutrient and water addition. Important findings Nutrient addition increased plant biomass by 32.55% compared with control. High-level water supply increased plant biomass by 31.35% and the combination of nutrient and high-level water addition increased plant biomass by 110.60%. Nutrient, water, species identity and their two-way interactions significantly affected plant biomass. Changes in total plant K:Ca, K:Mg, K:Mn, K:Zn and Mg:Mn were significantly and positively related to changes in plant biomass. The ratio between the concentrations of macro-elements and micro-elements tended to increase with biomass. Species identity and treatment had no effects in most of these relationships, suggesting that the changes in stoichiometry were mostly driven by the variations in biomass. The relationships between changes in stoichiometry and in biomass also occurred in leaves, stems and roots. The covariation between plant stoichiometry and biomass can have profound effects on ecosystem functioning under the global environmental changes.

Key words: ecological stoichiometry, micro-element, macro-element, plasticity, biomass