Zhu Ruirui, Xiu Danping, Xue Ruixin, Teng Shuo
College of Architecture and Urban Planning, Qingdao University of Technology, Qingdao, China.
Heliyon. 2024 Aug 30;10(18):e36901. doi: 10.1016/j.heliyon.2024.e36901. eCollection 2024 Sep 30.
The distribution and diversity of woody vegetation are crucial for understanding the structure and ecology of urban forests. As urbanization accelerates, the construction and composition of urban forests vary significantly along the urban-rural gradient. Qingdao's urban forests offer an opportunity to test the relationship between the diversity of woody plants and the urban-rural gradient. We classified the urban-rural gradient using imperviousness and construction time, then investigated the diversity of woody plants in Qingdao's urban forests under different urban-rural gradients and tested the reasonableness of their allocation. Correlation analysis found that the diversity index of woody plants in urban forests was highly connected to the urban-rural gradient (by imperviousness: r = -0.589, r = -0.373, r = -0.170, r = 0.272/by construction time: r = -0.530, r = -0.360, r = -0.148, r = 0.272/0.174). With a decrease in urbanization density, the Margalef (), Shannon-Wiener (), and Simpson () indices all decreased while the Pielou () index increased. The four diversity indices showed a substantial correlation with one another, but not with the Margalef and Pielou indices. The analysis utilizing the 10/20/30 rule of empirical demonstrates a clear irrationality in allocating shrub species in Qingdao's urban forests, and the distribution of tree species is reasonable. Based on the study results, strategies for optimizing and enhancing urban forests in Qingdao are proposed for different urban-rural gradients, respectively. This study can provide a scientific framework for urban biodiversity conservation and management in Qingdao and serve as a guide for urban forests and greening with comparable climates.
木本植被的分布和多样性对于理解城市森林的结构和生态至关重要。随着城市化进程的加速，城市森林的建设和组成沿城乡梯度变化显著。青岛的城市森林为检验木本植物多样性与城乡梯度之间的关系提供了契机。我们利用不透水率和建设时间对城乡梯度进行分类，然后调查了青岛城市森林在不同城乡梯度下木本植物的多样性，并检验了其配置的合理性。相关性分析发现，城市森林中木本植物的多样性指数与城乡梯度高度相关（按不透水率：r = -0.589，r = -0.373，r = -0.170，r = 0.272/按建设时间：r = -0.530，r = -0.360，r = -0.148，r = 0.272/0.174）。随着城市化密度的降低，Margalef（）、Shannon-Wiener（）和Simpson（）指数均下降，而Pielou（）指数上升。这四个多样性指数彼此之间呈现出显著的相关性，但与Margalef指数和Pielou指数不相关。利用经验法则的10/20/30规则进行的分析表明，青岛城市森林中灌木物种的配置存在明显不合理性，而乔木物种的分布是合理的。基于研究结果，分别针对不同的城乡梯度提出了优化和提升青岛城市森林的策略。本研究可为青岛城市生物多样性保护和管理提供科学框架，并为气候相似地区的城市森林和绿化提供指导。
