How urban street trees respond to climate stressors: variations in radial growth and resilience in a temperate coastal area

Abstract The effects of climate change in recent decades, driven by rising global temperatures and drought, have increasingly influenced urban tree growth. This study used tree-ring width chronologies of two dominant urban street tree species for two time periods, 1979–2009 versus 2009–2022 in deodar cedar (Cedrus deodara) and 1960–2010 versus 2010–2022 in London planetree (Platanus × hispanica), to analyze the response of radial growth to climate (e.g. drought stress and temperature) and to compare their growth resilience to drought events in a temperate coastal city in eastern China. Growth in both species showed correlations with moisture availability (i.e. precipitation, the 6-month Standard Precipitation Evapotranspiration Index, and the Palmer Drought Severity Index). Reduced radial growth in Deodar cedar was correlated with drought stress during the previous autumn and winter. Current year growth was also positively correlated with higher temperatures in the previous September–December for deodar cedar and the previous September for London planetree. Deodar cedar also showed a significantly negative response to temperature during the current growing season. These results suggest that deodar cedar was more sensitive to climatic factors than London planetree. Results are also consistent with the common observation that London planetree is a strong and adaptive tree species for urban environments. Under recent (e.g. 2009/2010–2022) warming and drying climatic conditions, growth declined in both species, with deodar cedar being more affected. Resilience to drought stress was also tested in the two tree species, which exhibited different responses. Notably, deodar cedar showed greater recovery, but lower resistance and resilience than London planetree. The results highlight the differing adaptability of these two species to climate change and provide a scientific basis for developing urban tree management strategies.