Variation in plant carbon, nitrogen and phosphorus contents across the drylands of China

Determining large-scale patterns of plant elemental concentrations and stoichiometry along environmental gradients is critical for understanding plant adaptive strategies and predicting ecosystem biogeochemistry processes. However, it remains unclear as to how plant carbon (C), nitrogen (N), and phosphorus (P) concentrations and their stoichiometry in different organs (leaves, stems, and roots) respond to large-scale environmental gradients in drylands. We determined C, N, and P concentrations and their ratios in leaves, stems, and roots of plants growing in the dryland ecosystems of China. Using threshold indicator taxa analyses, we identified indicator species of plant C, N, and P responses to aridity and soil properties. The arithmetic averaged concentrations of C, N, and P in drylands were 414, 18.7, and 1.38 mg/g for leaves, respectively; 445, 12.1, and 1.08 mg/g for stems, respectively; and 418, 10.5, and 0.89 mg/g for roots, respectively. The C : N, C : P, and N : P ratios...