The stoichiometric characteristics and the relationship with hydraulic and morphological traits of the Faxon fir in the subalpine coniferous forest of Southwest China

•Faxon fir showed a preferentially nutrient allocation to needles than other organs.•With the elevation increasing, Faxon fir may be limited by P.•As the climate warms, high-altitude Faxon fir will be increasingly with N-restricted.•Faxon fir made a cooperative change among nutrient, hydraulic, and morphological. High-altitude mountain plants are at risk of extinction due to global warming. Our study examined the stoichiometric characteristics of high-altitude plants in response to a progressively warming climate, as well as exploring potential relationships between hydraulic conductivity efficiency, stoichiometric characteristics, and morphological traits. As the research object, it was decided to conduct this investigation using the Faxon fir, a dominant species in the Minjiang River Basin with better water conditions. The sampling time was four months. In July 2019, October 2019, January 2020, and April 2020, the stoichiometric characteristics (N and P) in needles, branches, stems, and roots of Faxon fir were measured along an altitude gradient at 200 m intervals from 2800 m to 3600 m. We also measured morphological traits and hydraulic traits. This study showed that the Faxon fir N P stoichiometric preferentially to needles, followed by branches and roots, and finally at the trunk, and the Faxon fir was in an N-restricted state. N and P elements exhibit a significant correlation with morphological traits, while the relationship between P elements and hydraulic characteristics is mediated indirectly through morphological traits. At high altitudes, climate warming will increase the N limitation of Faxon fir, but the effect on P limitation will be relatively limited. Climate environment and water status are closely related to the distribution of N P nutrients in the organs. Undoubtedly, climate change will directly affect the survival of high-altitude plants, and appropriate survival strategies can encourage plants to adapt to climate changes by balancing energy distribution among different organs and tissues.