VanderHeyden D, Skelly J, Innes J, Hug C, Zhang J, Landolt W, Bleuler P
Graduate Ecology Program, Pennsylvania State University, University Park, PA 16802, USA.
Environ Pollut. 2001;111(2):321-31. doi: 10.1016/s0269-7491(00)00060-9.
Canton Ticino in southern Switzerland is exposed to some of the highest concentrations of tropospheric ozone in Europe. During recent field surveys in Canton Ticino, foliar symptoms identical to those caused by ozone have been documented on native tree and shrub species. In Europe, the critical ozone level for forest trees has been defined at an AOT40 of 10 ppm.h O3 (10 ppm.h accumulated exposure of ozone over a threshold of 40 ppb) during daylight hours over a six-month growing season. The objective of this study was to determine the amount of ambient ozone required to induce visible foliar symptoms on various forest plant species in southern Switzerland. Species were grown within eight open-top chambers and four open plots at the Vivaio Lattecaldo Cantonal Forest Nursery in Ticino, Switzerland. Species differed significantly in terms of the ppb.h exposures needed to cause visible symptoms. The most to least symptomatic species grown within open-plots in this study rank as Prunus serotina, Salix viminalis, Vibrnum lantana, Rhamnus cathartica, Betula pendula, Rumex obtusifolius, Sambucus racemosa, Morus nigra, Prunus avium, Fraxinus excelsior, Rhamnus frangula, Alnus viridis, Fagus sylvatica and Acer pseudoplatanus. Similar rankings were obtained in the non-filtered chamber plots. The ranking of species sensitivity closely follows AOT values for the occurrence of initial symptoms and symptom progression across the remainder of the exposure season. Species that first showed evidence of foliar injury also demonstrated the most sensitivity throughout the growing season, with symptoms rapidly advancing over ca. 25-30% of the total plant leaf surfaces by the end of the observation period. Conversely, those species that developed symptoms later in the season had far less total injury to plant foliage by the end of the observation period (1.5 to < 5% total leaf area injured). The current European ambient ozone standard may be insufficient to protect native plant species from visible foliar injury, and many more native species may be sensitive to ozone-induced foliar injury than are currently known.
瑞士南部的提契诺州面临着欧洲对流层臭氧浓度最高的地区之一。在最近对提契诺州的实地调查中，已记录到本地树木和灌木物种出现了与臭氧造成的症状相同的叶片症状。在欧洲，森林树木的临界臭氧水平被定义为在六个月的生长季节白天时段，AOT40为10 ppm·h O₃（臭氧在40 ppb阈值以上的累积暴露量为10 ppm·h）。本研究的目的是确定在瑞士南部各种森林植物物种上诱发可见叶片症状所需的环境臭氧量。这些物种在瑞士提契诺州拉泰卡尔多州立森林苗圃的八个开放式气室和四个露天地块中种植。不同物种在导致可见症状所需的ppb·h暴露量方面存在显著差异。在本研究中，在露天地块中生长的症状最明显到最不明显的物种依次为黑樱桃、多花柳、香荚蒾、鼠李、垂枝桦、钝叶酸模、接骨木、黑桑、甜樱桃、欧洲白蜡树、欧亚鼠李、绿桤木、欧洲山毛榉和假挪威槭。在未过滤的气室地块中也获得了类似的排名。物种敏感性排名与整个暴露季节初始症状出现和症状进展的AOT值密切相关。最早出现叶片损伤迹象的物种在整个生长季节也表现出最高的敏感性，到观察期结束时，症状迅速蔓延至约25 - 30%的植物总叶面积。相反，那些在季节后期出现症状的物种在观察期结束时对植物叶片的总损伤要小得多（总叶面积损伤为1.5%至小于5%）。当前的欧洲环境臭氧标准可能不足以保护本地植物物种免受可见的叶片损伤，而且可能有更多的本地物种对臭氧诱导的叶片损伤敏感，超出目前所知的范围。
