Leaf C:N:P stoichiometric homeostasis of a Robinia pseudoacacia plantation on the Loess Plateau

Homeostasis is the adaptability of a species to a changing environment. However, the ecological stoichiometric homeostasis of Robinia pseudoacacia L. in different climatic regions is poorly understood but could provide insights into its adaptability in the loess hilly region. This study sampled 20 year-old R. pseudoacacia plantations at 10 sites along a north–south transect on the Loess Plateau. Variations in the ecological stoichiometric characteristics of leaf and soil carbon, nitrogen, and phosphorus were analysed and homeostatic characteristics of leaf ecological stoichiometric parameters in different climates were identified. Factors affecting leaf stoichiometry were assessed. The results show that R. pseudoacacia leaves were rich in nitrogen and deficient in phosphorous during tree growth and development. Nitrogen and phosphorous levels in the soils of the loess region were lower than the average in soils in the rest of China. All ecological stoichiometric parameters of R. pseudoacacia leaves in two different climates were considered “strictly homeostasis”. Precipitation, available phosphorus, and soil C:P were the main factors affecting the variation of C:N:P stoichiometry of R. pseudoacacia leaves. R. pseudoacacia in the loess hilly region has strong ecologically homeostatic characteristics and suggests that it is well-adapted to the area.