In recent years, the ecosystem of the Tianshan wild fruit forest in China has suffered damages due to various factors. This is particularly evident in Xinyuan County, Xinjiang, where the population of wild apple trees has declined dramatically, with a mortality rate reaching as high as 80%.

A group of researchers led by Prof. ZHANG Yuanming from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences conducted a four-year nutrient addition experiment in a wild fruit forest in Xinyuan County to determine the optimal fertilisation method for Xinjiang wild apple seedlings. The findings were published in Plant, Cell and Environment.

Researchers investigated the responses of functional traits of Xinjiang wild apple seedlings (Malus sieversii) to varying levels of nitrogen (N) addition, phosphorus (P) addition, and N×P interaction. Plant trait network analysis (PTNs) was employed to explore the differences among multiple traits at different levels, and to determine the most effective nutrient management strategies.

Researchers found that Xinjiang wild apple seedlings exhibited differential responses to N addition, P addition, and N×P interaction at the physiological level. Specifically, N addition had a significant effect on leaf-specific and wood-specific hydraulic conductivity, and percentage loss of conductivity; P addition only had a significant effect on wood-specific hydraulic conductivity; N×P interaction had no significant effect on all physiological traits.

“For wild apple seedlings in this region, N10 (10 g m⁻² yr⁻¹) and N20 (20g m⁻² yr⁻¹) are the most suitable fertilizer types, in contrast, phosphorus fertilizers were less suitable,” said ZHANG Yuanming, the corresponding author of this study.

This study provides insight into the nutrient requirements for the cultivation of Xinjiang wild apple seedlings, and the developing protection and management strategies for the ecosystem of the Tianshan wild fruit forest.