Response of leaf stoichiometry of Potentilla anserina to elevation in China's Qilian Mountains

Plants adapt to changes in elevation by regulating their leaf ecological stoichiometry. Potentilla anserina L. that grows rapidly under poor or even bare soil conditions has become an important ground cover plant for ecological restoration. However, its leaf ecological stoichiometry has been given little attention, resulting in an insufficient understanding of its environmental adaptability and growth strategies. The objective of this study was to compare the leaf stoichiometry of P. anserina at different elevations (2,400, 2,600, 2,800, 3,000, 3,200, 3,500, and 3,800 m) in the middle eastern part of Qilian Mountains. With an increase in elevation, leaf carbon concentration [(C)(leaf)] significantly decreased, with the maximum value of 446.04 g·kg(−1) (2,400 m) and the minimum value of 396.78 g·kg(−1) (3,500 m). Leaf nitrogen concentration [(N)(leaf)] also increased with an increase in elevation, and its maximum and minimum values were 37.57 g·kg(−1) (3,500 m) and 23.71 g·kg(−1) (2,800 m), respectively. Leaf phosphorus concentration [(P)(leaf)] was the highest (2.79 g·kg(−1)) at 2,400 m and the lowest (0.91 g·kg(−1)) at 2,800 m. The [C](leaf)/[N](leaf) decreased with an increase in elevation, while [N](leaf)/[P](leaf) showed an opposite trend. The mean annual temperature, mean annual precipitation, soil pH, organic carbon, nitrogen, and phosphorus at different elevations mainly affected [C](leaf), [N](leaf), and [P](leaf). The growth of P. anserina in the study area was mainly limited by P, and this limitation was stronger with increased elevation. Progressively reducing P loss at high elevation is of great significance to the survival of P. anserina in this specific region.