Abstract: In recent years, the geographic variation in the plant stoichiometry has become as the center of studying the structure and function of ecosystems with global climate change. This resarch explored the relationship between the biodiversity and the foliar stoichiometry (C, N and P contents) in 7 different plant communities at different altitudes on the western slope of the Helan Mountain. The results showed that the species richness in plant community was decreased with the increase of elevation in lowaltitude areas in the Helan Mountain, and there was no significant correlation between the species richness in plant community and the foliar stoichiometry (C, N and P contents and stoichiometric ratios and coefficients of variation of these indicators) in the Helan Mountain, which did not surpport the viewpoint that the value of species richness was higher when the foliar N[JP20]∶[JP]P mass ratio varied in a range of 14-16 than that when the foliar N[JP20]∶[JP]P mass ratio was higher than 14 or lower than 16, and the hypothesis that there was a positive correlation between the species richness and the variance of foliar mass ratio was surpported neither. Such results may be caused by the slight change of plant species richness in our research (9-16 plant species).   

Key words: font-size: 10.5pt, mso-bidi-font-family: 宋体, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, ecochemistry')">mso-bidi-language: AR-SA" lang="EN-US">ecochemistry, plant community, biodiversity, plant stoichiometry, nutrient content, Helan Mountain')">Helan Mountain