Plant Phenology and Its Anthropogenic and Natural Influencing Factors in Densely Populated Areas During the Economic Transition Period of China

Peijun Ju,Liangfeng Liu,Wenchao Yan,Yixin He,Huai Chen,Jianliang Liu,Xinwei Liu

doi:10.3389/fenvs.2021.792918

Abstract

As a sensitive, observable, and comprehensive indicator of climate change, plant phenology has become a vital topic of global change. Studies about plant phenology and its responses to climate change in natural ecosystems have drawn attention to the effects of human activities on phenology in/around urban regions. The key factors and mechanisms of phenological and human factors in the process of urbanization are still unclear. In this study, we analyzed variations in xylophyta phenology in densely populated cities during the fast urbanization period of China (from 1963 to 1988). We assessed the length of the growing season affected by the temperature and precipitation. Temperature increased the length of the growing season in most regions, while precipitation had the opposite effect. Moreover, the plant-growing season is more sensitive to preseason climate factors than to annual average climate factors. The increased population reduced the length of the growing season, while the growing GDP increased the length of the growing season in most regions (8 out of 13). By analyzing the impact of the industry ratio, we found that the correlation between the urban management of emerging cities (e.g., Chongqing, Zhejiang, and Guizhou) and the growing season is more significant, and the impact is substantial. In contrast, urban management in most areas with vigorously developed heavy industry (e.g., Heilongjiang, Liaoning, and Beijing) has a weak and insignificant effect on plant phenology. These results indicate that different urban development patterns can influence urban plant phenology. Our results provide some support and new thoughts for future research on urban plant phenology.

Highlights

In recent decades, the number of studies on plant phenology and the annual sequence of plant developmental stages, has increased rapidly, providing vital information about how ecosystems respond to climate change (Menzel et al, 2006; Chuine and Régnière, 2017; Chen et al, 2018; Stucky et al, 2018)
We found a significant correlation between plant phenology and warming, consistent with other studies, which indicated that higher temperatures lengthen growing seasons (Menzel, 2003; Badeck et al, 2004; Cleland et al, 2007)
Compared with non-populated western China (Chen et al, 2011; Shen et al, 2011), our study found that precipitation has no significant influence on plant phenology, unlike temperature, in eastern China (Figure 6B)

Summary

Introduction

The number of studies on plant phenology and the annual sequence of plant developmental stages, has increased rapidly, providing vital information about how ecosystems respond to climate change (Menzel et al, 2006; Chuine and Régnière, 2017; Chen et al, 2018; Stucky et al, 2018). Satellite-based studies have revealed that the start of the growing season has been gradually earlier, and the end of the growing season has been delayed over the past 3 decades (Piao et al, 2006; Jeong et al, 2011; Zhu et al, 2012). Human activities such as urbanization are essential factors affecting climate conditions, soil properties, hydrology, and ecosystem processes (Ren et al, 2018). Urbanization and other human activities affect climate conditions, soil properties, hydrology, and ecosystem processes, so they influence plant phenology (Ren et al, 2018).

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Discussion

Conclusion