Leaf stoichiometry of common species along altitude gradients in the Qilian Mountains, China

Investigating the variations in leaf stoichiometry among plant common species at different altitudes, along with the factors that influence these variations and the adaptation strategies employed, holds significant importance for comprehending biogeochemical cycles amidst global environmental changes. In this research, we measured soil organic carbon and nutrient concentrations, as well as leaf stoichiometry for plant common species at five altitudes (2400 - 3200 m with an interval of 200 m) within the Qilian Mountains of Northwest China. This study aims to enhance our understanding of how plant common species in mountainous regions exhibit adaptable responses to altitude variations and how potential environmental changes in the future might impact their leaf functions. Results showed that the leaf C: N: P stoichiometry of plant common species varied differently with increasing altitude. Across altitudes, mean annual temperature (MAT), soil total phosphorus (STP), mean annual precipitation (MAP), soil water content (SWC) and soil nitrate nitrogen (NO3--N) were the main factors influencing leaf element concentrations of plant common species. However, leaf stoichiometric ratios were mainly determined by MAT, MAP and soil total nitrogen (STN). The effects of MAT and MAP on both leaf element concentrations and leaf stoichiometric ratios of plant common species were found to be significant. Plant growth in the study area was mainly limited by P. The results not only highlight the adaptive strategies employed by plants, but also help deepen the understanding of leaf stoichiometry, establishing connections between individual plant species and broader plant community composed of these common species.