Effects of Nitrogen and Water Addition on Leaf N ∶P Stoichiometry of the Two Dominant Species in Artemisia ordosica Community

【Objective】 A three-year(2015-2017) nitrogen and water addition control experiment was conducted in the southwestern margin of the Mu Us sandy land to investigate the effects and action pathways of increased nitrogen and moisture on the two dominant plant species(Artemisia ordosica and Leymus secalinus). This study was aimed to provide theoretical basis and case support for predicting nutrient cycling in desert ecosystems and nutrient limiting conditions for plant growth under future global environmental changes. 【Method】 For three successive years(2015-2017), a field control experiments with 2 factors and 9 interactive treatments were conducted in Ningxia Yanchi, Southwestern edge of Mu Us sandy land. Three nitrogen addition levels were N0(0 kg·hm-2a-1), N10(10 kg·hm-2a-1), and N60(60 kg·hm-2a-1). Three water addition levels were W0(natural precipitation), W20(20% increase over natural precipitation), and W40(40% increase over natural precipitation). We performed two-way ANOVAs to examine the responses of so