Morgan Patrick B, Mies Timothy A, Bollero Germán A, Nelson Randall L, Long Stephen P
Department of Plant Biology, University of Illinois, 379 Edwin R. Madigan Laboratory, 1201 West Gregory, Urbana, IL 61801, USA.
New Phytol. 2006;170(2):333-43. doi: 10.1111/j.1469-8137.2006.01679.x.
Mean surface ozone concentration is predicted to increase 23% by 2050. Previous chamber studies of crops report large yield losses caused by elevation of tropospheric ozone, and have been the basis for projecting economic loss. This is the first study with a food crop (soybean, Glycine max) using free-air gas concentration enrichment (FACE) technology for ozone fumigation. A 23% increase in ozone concentration from an average daytime ambient 56 p.p.b. to a treatment 69 p.p.b. over two growing seasons decreased seed yield by 20%. Total above-ground net primary production decreased by 17% without altering dry mass allocation among shoot organs, except seed. Fewer live leaves and decreased photosynthesis in late grain filling appear to drive the ozone-induced losses in production and yield. These results validate previous chamber studies suggesting that soybean yields will decrease under increasing ozone exposure. In fact, these results suggest that when treated under open-air conditions yield losses may be even greater than the large losses already reported in earlier chamber studies. Yield losses with elevated ozone were greater in the second year following a severe hailstorm, suggesting that losses caused by ozone might be exacerbated by extreme climatic events.
预计到2050年，地表平均臭氧浓度将增加23%。此前针对农作物的室内研究报告称，对流层臭氧浓度升高会导致大幅减产，这些研究一直是预测经济损失的依据。这是首次利用自由空气气体浓度富集（FACE）技术对粮食作物（大豆，即 Glycine max）进行臭氧熏蒸的研究。在两个生长季中，臭氧浓度从白天平均环境浓度56 ppb增加到处理浓度69 ppb，增幅为23%，导致种子产量下降了20%。地上部分总净初级生产力下降了17%，且除种子外，各地上器官间的干物质分配未发生改变。活叶数量减少以及籽粒灌浆后期光合作用降低，似乎是臭氧导致产量和生产力损失的原因。这些结果证实了此前室内研究的结果，即臭氧暴露增加会导致大豆产量下降。实际上，这些结果表明，在露天条件下进行处理时，产量损失可能比早期室内研究报告的巨大损失还要大。在一场严重冰雹灾害后的第二年，臭氧浓度升高导致的产量损失更大，这表明极端气候事件可能会加剧臭氧造成的损失。
