Chin J Plant Ecol ›› 2019, Vol. 43 ›› Issue (6): 482-489.DOI: 10.17521/cjpe.2019.0064

Special Issue: 生态化学计量

• Research Articles • Previous Articles     Next Articles

C, N and P stoichiometric ratios in mixed evergreen and deciduous broadleaved forests in Shennongjia, China

LIU Lu1,2,GE Jie-Lin1,SHU Hua-Wei3,ZHAO Chang-Ming1,XU Wen-Ting1,SHEN Guo-Zhen1,XIE Zong-Qiang1,2,*()   

  1. 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2 University of Chinese Academy of Sciences, Beijing 100049, China
    3 State-owned Longmenhe Forest Farm, Xingshan, Hubei 443700, China
  • Received:2019-03-22 Revised:2019-05-24 Online:2019-06-20 Published:2019-09-30
  • Contact: XIE Zong-Qiang
  • Supported by:
    Supported by Frontier Science Key Research Project of Chinese Academy of Sciences(QYZDY-SSW-SMC011)


Aims Ecological stoichiometry focuses on the balance of chemical elements in ecological processes, in which the stoichiometric ratios of carbon (C), nitrogen (N) and phosphorus (P) are important features of ecological functions. The objectives of this study were to determine the stoichiometric characteristics in different organs and components of mixed evergreen and deciduous broadleaved forests, and to examine the discrepancy in stoichiometric ratios among different components of the ecosystem and plant organs. Methods We measured the concentrations of C, N and P in different plant organs, litter and soil in a mixed evergreen and deciduous broadleaved forest in Shennongjia of Hubei Province, China, and computed the stoichiometric ratios using the biomass-weighted mean method. Important findings The C concentration, C:N and C:P of different components were ranked in the order of plant community > litter > soil, and concentrations of N and P and N:P in the order of litter > plant community > soil. There were little differences in C concentration among various organs, with the coefficient of variation (CV) much lower and less variable than that for N and P concentrations. Both N and P concentrations were highest in leaves with the lowest CV value; N:P was highest in the bark, but with the lowest CV value in branches. Additionally, there were considerable differences in N and P concentrations in leaves between evergreen and deciduous species. Compared with other forest types, this forest had lower C:P and N:P ratios in plant community, higher C:P and N:P ratios in litter, and the C, N and P stoichiometric ratios in soils were consistent with, and the C:N ratio in ecosystem was lower than, that in subtropical evergreen broadleaved forests. Our findings demonstrated the patterns of differences among components in stoichiometry using the integral biomass-weighted mean method differ from that using the arithmetic mean method in selective organs. Furthermore, the distribution and homeostasis of C, N and P concentrations and their stoichiometric ratios could be closely related to the physiology of different organs.

Key words: biomass-weighted mean method, organ, plant community, ecosystem, homeostasis