Abstract: Aims The survival and growth of woody plant seedlings are regulated by a complex interplay of multiple environmental factors. However, how the forest canopy regulates understory herbaceous cover and microclimate to subsequently influence seedling survival and growth remains poorly understood. Methods This study investigated seedlings of three dominant species, Malus sieversii, Juglans regia, and Prunus armeniaca, in wild fruit forests in the Tianshan Mountains through five consecutive years of field surveys and microclimate monitoring. Important findings Our results show that canopy cover indirectly influenced the survival of seedlings of the three wild fruit tree species by regulating understory microclimate and herbaceous cover. Among these factors, herbaceous cover was an important determinant of seedling survival,existing negative effects on seedlings of M. sieversii and P. armeniaca, while demonstrating a positive effect on seedlings of J. regia. In terms of seedling growth, the key limiting factors differed among species. The growth of seedlings of M. sieversii was mainly affected by soil pH and herbaceous cover; the growth of seedlings of J. regia was primarily associated with herbaceous cover and mean temperature of the growing season; whereas the growth of seedlings of P. armeniaca was mainly constrained by mean temperature of the growing season. In conclusion, canopy cover regulates the survival and growth of wild fruit tree seedlings through multiple direct and indirect pathways, and the responses of seedlings of different tree species to biotic and abiotic factors differ significantly. The conservation and restoration of wild fruit forests should fully consider the differential responses of seedlings for different tree species to environmental factors and adopt targeted habitat management measures in the Tianshan Mountains.

Key words: Wild fruit forest, Seedlings, Canopy