Volatile organic compound (VOCs) emission is an important cause of photochemical smog and particulate pollution in urban areas, and urban vegetation has been presented as an important source. Different tree species have different emission levels, so adjusting greening species collocation is an effective way to control biogenic VOC pollution. However, there is a lack of measurements of tree species emission in subtropical metropolises, and the factors influencing the species-specific differences need to be further clarified. This study applied an in situ method to investigate the isoprene emission rates of 10 typical tree species in subtropical metropolises. Photosynthesis and related parameters including photosynthetic rate, intercellular CO₂ concentration, stomatal conductance, and transpiration rate, which can influence the emission rate of a single species, were also measured. Results showed Salix babylonica always exhibited a high emission level, whereas Elaeocarpus decipiens and Ligustrum lucidum maintained a low level throughout the year. Differences in photosynthetic rate and stomatal CO₂ conductance are the key parameters related to isoprene emission among different plants. Through the establishment of emission inventory and determination of key photosynthetic parameters, the results provide a reference for the selection of urban greening species, as well as seasonal pollution control, and help to alleviate VOC pollution caused by urban forests.

中文翻译：

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亚热带大都市10种典型树种异戊二烯排放速率对光合作用及相关生理参数的影响

挥发性有机化合物（VOCs）的排放是造成城市地区光化学烟雾和微粒污染的重要原因，而城市植被已被认为是重要的污染源。不同的树种具有不同的排放水平，因此调节绿化树种的搭配是控制生物VOC污染的有效方法。但是，在亚热带大都市中缺少对树木物种排放的测量，因此需要进一步阐明影响物种特定差异的因素。本研究采用原位方法研究了亚热带大都市中10种典型树种的异戊二烯排放速率。光合作用及相关参数，包括光合速率，细胞间CO ₂还测量了浓度，气孔导度和蒸腾速率，这些浓度会影响单个物种的排放速率。结果表明，柳柳始终表现出较高的排放水平，而大果El和女贞在全年中都保持较低水平。光合速率和气孔CO ₂电导率的差异是不同植物间异戊二烯排放的关键参数。通过建立排放清单并确定关键的光合参数，研究结果可为城市绿化树种的选择，季节性污染控制提供参考，有助于减轻城市森林对VOC的污染。