[Changes of plant leaf N, P, and K concentrations and species dominance in an arid-hot valley after ecosystem restoration].

Taking the arid-hot valley of Jinsha River, Southwest China as the object, a comparative study was made on the plant leaf N, P, and K concentrations and ratios as well as their relationships with species dominance in the restoration area and disturbed area, aimed to understand the effects of ecosystem restoration on the plant leaf stoichoimetric characteristics. Ecosystem restoration decreased the plant leaf N and P concentrations and P/K ratio significantly, but had lesser effects on the plant leaf K concentration. In restoration area, the plant leaf N, P, and K concentrations were averagely 10. 405, 0. 604, and 9. 619 g kg-1, being 16. 9% , 34. 9% , and 4. 7% lower than those in disturbed area, respectively. In restoration area, species dominance was significantly negatively correlated with plant leaf P concentration; while the species dominance in disturbed area had a significant negative correlation with plant leaf K concentration. Ecosystem restoration altered the slope and intercept of the scaling relationships among the plant leaf N, P, and K. No significant differences were observed in the leaf N, P, and K concentrations of the same plant species between restoration area and disturbed area, suggesting that the changes of plant leaf stoichiometric characteristics were mainly driven by the shift of species composition in the plant community.