**5. Conclusions**

Focused on Hangzhou, a typical subtropical metropolis, to investigate the impact of urbanization on plant phenology. Vegetation index-based phenology data and land surface temperature data were adopted to analyze the urban–rural gradient in phenology characteristics and the contributions of ΔLST to the ΔSOS under urbanization. We found that there was a negative coupling between SOS and LST in over 90% of the vegetated areas in Hangzhou. At the sample-point scale, SOS was weakly, but significantly, negatively correlated with LST at the daytime (R<sup>2</sup> = 0.2 and *p* < 0.01 in rural; R<sup>2</sup> = 0.14 and *p* < 0.05 in urban) rather than that at nighttime. Besides, the ΔSOS dominated by the ΔLST contributed more than 70% of the total ΔSOS. We consider that the achievements of this study will provide quantitative evidence for the impact of urbanization on the plant phenology, and help to deepen the understanding of urban ecosystem adaptation under intensive human activities.

**Author Contributions:** Conceptualization, J.J.; data curation, Y.J.; formal analysis, Y.J.; investigation, Y.J.; methodology, Y.J. and J.J.; project administration, J.J.; resources, J.J.; supervision, J.J.; validation, Y.J.; visualization, Y.J.; writing—original draft, Y.J.; writing—review and editing, J.J., W.Z., F.G. and T.Y. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported in part by National Natural Science Foundation of China (grant No. 41971374), Fundamental Research Funds for the Central Universities (grant No. B200202016) and Jiangsu Provincial Natural Science Foundation (grant No. BK20180009).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The study did not report any data.

**Acknowledgments:** We are grateful to NASA's Land Processes Distributed Active Archive Center (LP DAAC) and Gong Peng Research Group of Tsinghua University for providing the MODIS products and the multi-temporal dataset Global Urban Boundary, respectively. Additionally, we express our gratitude to anonymous reviewers and editors for their professional comments and suggestions.

**Conflicts of Interest:** The authors declare no conflict of interest.
