Abstract: Aims：This study aims to elucidate the annual growth dynamics of landscape trees under urban environmental conditions in Shenyang and their response to meteorological factors, thereby providing a reference for the cultivation and maintenance of ornamental tree species in Shenyang and the Northeast China region. Methods：This study employed the micro-core technique to monitor the radial growth dynamics of two urban tree species, Picea koraiensis and Phellodendron amurense, over two consecutive growing seasons (2023-2024) in Shenyang. The growth data were analyzed alongside meteorological data to elucidate the trees' response mechanisms to environmental factors. Important findings：Our investigation yielded two principal findings: (1) Cambial reactivation in both species initiated between late April and early May. The phase of cell enlargement and subsequent secondary wall thickening commenced approximately one week post-reactivation. Radial growth culminated in July, with complete growth cessation occurring by early to mid-October. The mean annual growth duration was quantified as 176 days for Picea koraiensis and 168 days for Phellodendron amurense. (2) The onset of cambial activity was positively correlated with rising temperature and precipitation early in the growing season. In contrast, the timing of growth cessation was independent of the reactivation chronology. Temperature was identified as the predominant environmental factor governing the radial growth dynamics of both species. This research provides a systematic characterization of the sp-temporal patterns of xylem development (xylogenesis) and the associated response mechanisms to environmental cues in Picea koraiensis and Phellodendron amurense within Shenyang's urban ecosystem. The insights gained offer a scientific basis for refining cultivation protocols and implementing precision silvicultural management for urban landscape trees across Shenyang and the Northeast China region.

Key words: radial growth, Picea koraiensis, Phellodendron amurense, microcoring, xylem