Urban hedgerows can act as barriers to roadside particulate air pollution, but details on methodologies to quantify pollutant capture, most efficient species to use, and practical planning advice are still evolving. We aimed to compare three widely used approaches to quantify particulate accumulation and deposition, and to ascertain the most cost-effective and robust approach for the rapid screening of various types of hedges. Secondly, using the most efficient methodology, we screened the summertime deposition of particulates on roadside hedges in Reading (UK), not just on species with differing leaf surface characteristics, but also along a transect of the hedge depth. Finally, we also compared particles’ capture by hedge leaf surfaces in locations with different traffic intensities, to try and ascertain the extent of reduction of particles’ concentration in various hedge types and urban locations. Results suggest that the gravimetric determination of particulate capture was most rapid and cost-effective, while being least technically demanding. We confirmed that hairy and more complex leaves captured most particulates, particularly in the >10 μm range. However, species choice only had a significant impact on the extent of capture on major roads, where the pollutant concentrations were highest. Furthermore, only hedge depths in excess of 2 m were found to noticeably reduce the concentration of fine particles in species with less capacity for particulates’ capture. Findings complement the growing body of knowledge to guide urban and landscape planners in choosing the most appropriate species to mitigate air quality in various urban contexts.

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评价城市树篱作为空气污染屏障的有效性：采样方法，物种特征和场所位置的重要性

城市树篱可以成为路边微粒空气污染的障碍，但是有关量化污染物捕获方法，最有效使用的物种以及实用的规划建议的细节仍在不断发展。我们旨在比较三种广泛使用的量化颗粒堆积和沉积的方法，并确定用于快速筛选各种类型的树篱的最具成本效益和最可靠的方法。其次，我们使用最有效的方法，对夏季在英国雷丁（Reading）（英国）的路边树篱上的颗粒物沉积进行了筛选，不仅是对具有不同叶表面特征的物种，还对树篱深度的横断面进行了筛选。最后，我们还比较了在交通强度不同的位置通过绿篱叶子表面捕获的颗粒，试图确定各种树篱类型和城市地区颗粒物浓度降低的程度。结果表明，重量法测定颗粒物的捕获速度最快，成本效益最高，而对技术的要求最低。我们确认，多毛且较复杂的叶子捕获了大多数颗粒，尤其是在> 10μm的范围内。但是，物种选择仅对污染物浓度最高的主要道路的捕获程度产生重大影响。此外，仅发现超过2 m的树篱深度会显着降低物种中细颗粒的浓度，而这些颗粒的捕集能力却较小。