Future N deposition and precipitation changes will be beneficial for the growth of Haloxylon ammodendron in Gurbantunggut Desert, northwest China

Evaluation of precipitation and nitrogen (N) deposition in desert ecosystems helps to elucidate the reaction of desert ecosystems to future environmental changes. An in-situ field experiment was established to examine the influence of a long-term enhanced precipitation and N deposition on the photosynthetic traits and physiological characteristics of Haloxylon ammodendron in the Gurbantunggut Desert, northwest China, throughout the growing season in 2014–2016. Results showed a significant interaction between precipitation and N applications. Increased precipitation and N deposition and their coupling could significantly improve photosynthetic capacity, alter the variability in amplitude of water potential and change the content of substances regulating osmotic pressure in H. ammodendron. According to the comprehensive evaluation of H. ammodendron’s adaptability using six different water and N coupling models, a combination of a 30% increase in precipitation and a 30 kg N ha−1 yr−1 addition in nitrogen deposition, or the addition of N at a concentration of 60 kg N ha−1 yr−1 with natural precipitation were beneficial to H. ammodendron growth and development. Hence, changes in the future global environment can be anticipated to be beneficial to H. ammodendron growth.