Exploring the impact of changing landscape patterns on ecological quality in different cities: A comparative study among three megacities in eastern and western China

Abstract

The landscape pattern emerges from the intricate interplay among natural, biological, and social elements, profoundly influencing the quality of the regional ecological environment. By comparing the spatial and temporal driving mechanisms of landscape pattern changes on ecological environment quality across various cities, we can gain valuable insights into charting sustainable development paths for cities in the future. The results show that: (1) From 1990 to 2020, the mean RSEI values for Kunming and Nanjing exhibited a certain degree of increase, suggesting an improvement in ecological quality over time. Conversely, Guangzhou displayed relatively high and stable ecological quality throughout the studied period. (2) The CA-Markov results reveal minimal variations in the ecological quality of Kunming by 2035. Conversely, Nanjing experiences a decline in ecological quality, while Guangzhou demonstrates commendable achievements in ecological development, with an area accounting for moderate or higher ecological grades reaching 71.13%. (3) During the 30 years, the polarization of the three cities intensified and gradually formed a polycentric and clustered urban form. Among them, Nanjing and Guangzhou showed a fragmented landscape pattern, while the landscape diversity of Kunming is decreasing. (4) In terms of landscape pattern changes, Nanjing and Guangzhou showed a fragmented landscape pattern and increased landscape heterogeneity, but the degree of fragmentation and the rate of urban expansion in Guangzhou have been mitigated. In contrast, the spatial distribution of landscape patches in Kunming is becoming more clustered and the landscape diversity is decreasing. (5) The results of MGWR show that improving the landscape diversity, landscape patch aggregation and connectivity is beneficial to improving ecological quality. Overall, this study provides valuable insights and serves as a relevant reference for optimizing urban spatial structure in China and other developing countries' cities, aiming to foster sustainable and ecologically conscious urban development.