Measuring the spatial configuration of urban tree canopy: A new metric for assessing concentrated-dispersed patterns and their association with urban air quality

IF 6.7 2区环境科学与生态学 Q1 ENVIRONMENTAL STUDIES

Urban Forestry & Urban Greening Pub Date : 2025-09-18 DOI:10.1016/j.ufug.2025.129069

Li Wang , Bo Pang , Ning Ma , Yue Zheng , Jinyuan Xie , Lu Chen , Pei Li

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引用次数: 0

Abstract

Which spatial distribution pattern of urban tree cover—concentrated or dispersed—is more effective for improving air quality? This study proposes two novel indicators, namely the Urban Tree Cover Distribution (UTD) index and Urban Tree Cover Area (UTA) index, which are developed based on tree cover rate raster calculations. These indicators quantify the spatial structure and aggregation characteristics of tree cover across over 280 cities in China and reveal the spatiotemporal differentiation of tree cover configurations in these cities from 2000 to 2023. The analysis indicates that since 2016, the tree cover rate and spatial aggregation degree in Chinese cities have increased significantly, while urban PM₂.₅ concentrations have decreased. The spatial distributions of the UTD and UTA indices exhibit spatial autocorrelation, with distinct differences between northern and southern China. Empirical modeling shows that the concentration degree of the forest spatial pattern exerts a significant positive effect on urban air quality improvement, and this effect varies significantly across different regions of China. Index decomposition reveals that the spatial distribution effect of urban trees on air quality improvement is stronger than its scale effect. Additionally, the spatial spillover effect caused by variations in tree cover is highly significant, and the spatial agglomeration of urban tree planting shows a significant marginal increasing trend in suppressing PM₂.₅. This study concludes that cities should adopt a more concentrated tree-planting pattern, as this approach not only significantly improves air quality but also reduces economic costs.

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测量城市树冠的空间结构：一种评估集中-分散格局及其与城市空气质量关系的新指标

哪种城市树木覆盖的空间分布模式——集中还是分散——对改善空气质量更有效？本文提出了基于树木覆盖率栅格计算的城市树木覆盖分布（UTD）指数和城市树木覆盖面积（UTA）指数。这些指标量化了中国280多个城市树木覆盖的空间结构和聚集特征，揭示了2000 - 2023年中国城市树木覆盖格局的时空分异。分析表明，2016年以来，中国城市树木覆盖率和空间聚集度显著增加，城市PM₂含量显著增加。₅浓度已经降低。UTD和UTA指数的空间分布表现为空间自相关，南北差异显著。实证模型表明，森林空间格局的集中程度对城市空气质量的改善具有显著的正向影响，且这种影响在中国不同区域之间存在显著差异。指数分解表明，城市树木对空气质量改善的空间分布效应强于其规模效应。此外，由树木覆盖变化引起的空间溢出效应非常显著，城市植树的空间集聚在抑制PM₂.₅方面表现出显著的边际增长趋势。本研究的结论是，城市应该采取更集中的植树模式，因为这种方法不仅可以显著改善空气质量，还可以降低经济成本。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Urban Forestry & Urban Greening FORESTRY-

CiteScore

11.70

自引率

12.50%

发文量

289

审稿时长

70 days

期刊介绍： Urban Forestry and Urban Greening is a refereed, international journal aimed at presenting high-quality research with urban and peri-urban woody and non-woody vegetation and its use, planning, design, establishment and management as its main topics. Urban Forestry and Urban Greening concentrates on all tree-dominated (as joint together in the urban forest) as well as other green resources in and around urban areas, such as woodlands, public and private urban parks and gardens, urban nature areas, street tree and square plantations, botanical gardens and cemeteries. The journal welcomes basic and applied research papers, as well as review papers and short communications. Contributions should focus on one or more of the following aspects: -Form and functions of urban forests and other vegetation, including aspects of urban ecology. -Policy-making, planning and design related to urban forests and other vegetation. -Selection and establishment of tree resources and other vegetation for urban environments. -Management of urban forests and other vegetation. Original contributions of a high academic standard are invited from a wide range of disciplines and fields, including forestry, biology, horticulture, arboriculture, landscape ecology, pathology, soil science, hydrology, landscape architecture, landscape planning, urban planning and design, economics, sociology, environmental psychology, public health, and education.