The Adaptability of the Typical Urban Tree-shrub-herb Communities in Zibo, Shandong, China to the Intense Cooling in Late-spring

Abstract

Aims: This study evaluated the physiological responses of two typical urban tree-shrub-herb communities to a short-term intense late-spring cooling event and compared their capacity to buffer local microclimatic changes. Study Design: The study selected the following two typical tree-shrub-herb communities (Group-A and Group-B). The main species of Group-A include Acer palmatum Thunb., Euonymus japonicus 'Aureo-marginatus', Inula japonica; the main species of Group-B include Celtis tetrandra Roxb., Ligustrum × vicaryi Rehder, Cirsium setosum. Place and Duration of Study: Shandong Institute of Agricultural Engineering, Zibo City, Shandong Province, from April 18 to April 25, 2026. Methodology: The chlorophyll, malondialdehyde (MDA), soluble protein, and proline contents of the main species in the communities before cooling, after cooling, and after warming were measured, and the microclimate improvement effects of the two communities were compared. Results: At the community level, the Group-B community had a wide canopy and good shading, and its temperature-buffering capacity was superior to that of Group-A. At the species level, the soluble protein and proline contents of plant leaves in Group-B increased more rapidly than those in Group-A, while the increase in MDA content was lower than that in Group-A. The cold-stress resistance and recovery ability of Group-B were stronger. Conclusion:  The plant communities formed by large areas of shady tree canopies in urban green spaces can buffer the effects caused by drastic temperature fluctuations, as these plant communities have strong resistance to intense spring cooling and environmental stress. Moreover, increased density of the upper and lower layers in these plant communities can effectively reduce wind damage.