Abstract In this study, the effect of air pollution due to different traffic congestion of intersections and distance from intersection center on seed germination characteristics of Cupressus arizonica and Pinus nigra were studied in Urmia, Iran. At first, all intersections were classified into three classes of low, moderate and high traffic congestion using Urmia Traffic and Transport Organization report, and then 3 intersections were randomly selected from each class. Seed cones of C. arizonica and P. nigra that commonly planted in the boulevards leading to these intersections were collected at distances 0, 20, 40, 60, 80 and 100 m from the intersection center. The results showed that 1000 seed weight, germination rate (%), mean time to germination, Kotowski velocity coefficient, and maximum mean daily germination (peak value) of P. nigra seeds and only 1000 seed weight and seed germination rate (%) of C. arizonica significantly decreased with increasing traffic congestion. With increasing distance from intersection center, 1000 seed weight, seed germination rate (%) and mean time to germination of P. nigra in moderate traffic areas increased significantly. While, 1000 seed weight and seed germination rate (%) of C. arizonica in high and moderate traffic areas respectively followed the same circumstance. In general, both species were able to show the effect of air pollution as a bio-indicator, although, it seems that C. arizonica probably is more resistant to contaminants than P. nigra.

中文翻译：

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交通引起的空气污染对亚利桑那柏（Cupressus arizonica Green）和黑松（Pinus nigra Arnold）种子萌发的影响

摘要 本研究在伊朗乌尔米亚研究了不同路口交通拥堵和距路口中心距离造成的空气污染对柏树和黑松种子萌发特性的影响。首先使用乌尔米亚交通运输组织报告将所有路口分为低、中、高交通拥堵三个等级，然后从每个等级中随机选择3个路口。在距离交叉点中心 0、20、40、60、80 和 100 m 处收集通常种植在通向这些交叉点的​​林荫大道上的 C. arizonica 和 P. nigra 的种子锥。结果表明，千粒重、发芽率(%)、平均发芽时间、Kotowski速度系数和最大平均日发芽率(峰值)均在P. nigra 种子和仅 1000 粒种子重和 C. arizonica 的种子发芽率（%）随着交通拥堵的增加而显着降低。随着距交汇中心距离的增加，中等交通区域黑松的千粒重、种子发芽率(%)和平均发芽时间显着增加。而高、中交通区的千粒重和种子发芽率(%)分别与此相同。总的来说，这两个物种都能够将空气污染的影响作为生物指标显示出来，尽管似乎 C. arizonica 可能比 P. nigra 更能抵抗污染物。1000粒重、种子发芽率(%)和中等交通区黑斑病的平均发芽时间显着增加。而高、中交通区的千粒重和种子发芽率(%)分别与此相同。总的来说，这两个物种都能够将空气污染的影响作为生物指标显示出来，尽管似乎 C. arizonica 可能比 P. nigra 更能抵抗污染物。1000粒重、种子发芽率(%)和中等交通区黑斑病的平均发芽时间显着增加。而高、中交通区的千粒重和种子发芽率(%)分别与此相同。总的来说，这两个物种都能够将空气污染的影响作为生物指标显示出来，尽管似乎 C. arizonica 可能比 P. nigra 更能抵抗污染物。