Tree health status and its influencing factors in street green space of Xiong'an New Area, China.

We developed a health assessment system for arboreal species in street green spaces of Xiong'an New Area, which comprised 12 indicators with four dimensions: whole-tree, crown, foliage, and trunk, with health grades classified into levels Ⅰ-Ⅴ (corresponding to healthy, sub-healthy, moderate healthy, unhealthy, and mori-bund, respectively). We surveyed 24 roads with 1040 trees, belonging to 32 species, 17 genera, and 11 families. Healthy and sub-healthy individuals together accounted for 63.8%, while unhealthy and moribund trees accounted for 11.0% and 4.0%, respectively. The three tree species with the highest application frequency were Styphnolo-bium japonicum, Fraxinus chinensis, and Ginkgo biloba. There were significant differences in health status among the 14 tree species with application frequency >5%. Pinus bungeana exhibited the highest health grade, while Acer ×freemanii, G. biloba, Prunus ×yedoensis 'Somei-yoshino', and Prunus cerasifera 'Atropurpurea' showed relatively lower health grades. Nine factors were significantly correlated with tree health in the street green spaces of Xiong'an New Area, including crown width, tree height, species origin, adjacent land use type, planting scenario, tree pit type, underlying surface composition, planting time, and pruning intensity. Furthermore, there were significant interactive effects with tree species for crown width and pruning intensity. Arboreal trees in the street green spaces of Xiong'an New Area faced certain health risks. Prioritizing stress-resistant native species, improving site conditions according to species-specific requirements, standardizing planting and construction practices, and implementing precise maintenance management were key measures to enhance tree health.