Cui Xuan, Sun Tong, Lu Xuehe, Zhang Qian, Huang Qing, Zhang Haidong, Zeng Qianghao, Chen Suwan
School of Geography Science and Geomatics Engineering, Suzhou University of Science and Technology, Suzhou, 215000, China.
School of Geography Science and Geomatics Engineering, Suzhou University of Science and Technology, Suzhou, 215000, China; SuZhou Key Laboratory of Spatial Information Intelligent Technology and Application, Suzhou, 215000, China.
J Environ Manage. 2025 Aug;389:126096. doi: 10.1016/j.jenvman.2025.126096. Epub 2025 Jun 9.
Vegetation diversity in urban areas is crucial for maintaining urban ecological security. Rapid urbanization significantly affects vegetation diversity. However, the absence of effective regional-scale monitoring methods makes quantitative assessments challenging. This study used the remote sensing-based Rao's Q index to assess both the direct and indirect effects of urbanization on vegetation functional diversity in Suzhou, China, in 2021. Our results showed that the modified Rao's Q method effectively captured the spatial distribution patterns of urban vegetation functional diversity. Urban cores showed a 76.9 % reduction in functional diversity (Rao's Q = 0.003) compared to suburban areas (Rao's Q = 0.013), underscoring the substantial impact of urbanization on vegetation diversity. Direct effects increased with urbanization intensity (β); for every 1 % increase in β, Rao's Q declined by 1 %. Indirect effects displayed threshold behavior: they promoted diversity when β < 0.2, but became detrimental when β > 0.2 due to heightened environmental stress and human activities. In 2021, indirect effects mitigated the loss of functional diversity by an average of about 10 % in suburban areas. Partial correlation analysis revealed land surface temperature (LST) and urban greening (UG) as key factors influencing positive indirect impacts. LST enhanced functional diversity in low-urbanization zones, while intensive human activities accelerated its decline. UG was identified as a vital strategy for enhancing vegetation diversity in highly urbanized areas. These findings deepen our understanding of the impact of urbanization on vegetation functional diversity and offer valuable insights for developing adaptive policies to safeguard ecosystem services and improve urban living quality.
城市地区的植被多样性对于维持城市生态安全至关重要。快速城市化显著影响植被多样性。然而，缺乏有效的区域尺度监测方法使得定量评估具有挑战性。本研究使用基于遥感的Rao's Q指数评估2021年中国苏州城市化对植被功能多样性的直接和间接影响。我们的结果表明，改进后的Rao's Q方法有效地捕捉了城市植被功能多样性的空间分布模式。与郊区（Rao's Q = 0.013）相比，城市核心区的功能多样性降低了76.9%（Rao's Q = 0.003），突出了城市化对植被多样性的重大影响。直接影响随着城市化强度（β）的增加而增加；β每增加1%，Rao's Q下降1%。间接影响表现出阈值行为：当β < 0.2时，它们促进多样性，但当β > 0.2时，由于环境压力和人类活动加剧，它们变得有害。2021年，间接影响使郊区功能多样性的损失平均减轻了约10%。偏相关分析表明，地表温度（LST）和城市绿化（UG）是影响正向间接影响的关键因素。LST在低城市化地区增强了功能多样性，而密集的人类活动加速了其下降。UG被确定为在高度城市化地区增强植被多样性的一项重要策略。这些发现加深了我们对城市化对植被功能多样性影响的理解，并为制定适应性政策以保障生态系统服务和提高城市生活质量提供了有价值的见解。
