Percy Kevin E, Awmack Caroline S, Lindroth Richard L, Kubiske Mark E, Kopper Brian J, Isebrands J G, Pregitzer Kurt S, Hendrey George R, Dickson Richard E, Zak Donald R, Oksanen Elina, Sober Jaak, Harrington Richard, Karnosky David F
Natural Resources Canada, Canadian Forest Service-Atlantic Forestry Centre, Fredericton, New Brunswick, E3B 5P7, Canada.
Nature. 2002 Nov 28;420(6914):403-7. doi: 10.1038/nature01028.
Human activity causes increasing background concentrations of the greenhouse gases CO2 and O3. Increased levels of CO2 can be found in all terrestrial ecosystems. Damaging O3 concentrations currently occur over 29% of the world's temperate and subpolar forests but are predicted to affect fully 60% by 2100 (ref. 3). Although individual effects of CO2 and O3 on vegetation have been widely investigated, very little is known about their interaction, and long-term studies on mature trees and higher trophic levels are extremely rare. Here we present evidence from the most widely distributed North American tree species, Populus tremuloides, showing that CO2 and O3, singly and in combination, affected productivity, physical and chemical leaf defences and, because of changes in plant quality, insect and disease populations. Our data show that feedbacks to plant growth from changes induced by CO2 and O3 in plant quality and pest performance are likely. Assessments of global change effects on forest ecosystems must therefore consider the interacting effects of CO2 and O3 on plant performance, as well as the implications of increased pest activity.
人类活动导致温室气体二氧化碳和臭氧的背景浓度不断增加。在所有陆地生态系统中都能发现二氧化碳水平的上升。目前，世界上29%以上的温带和亚极地森林中存在有害的臭氧浓度，但预计到2100年，这一比例将达到60%（参考文献3）。尽管二氧化碳和臭氧对植被的单独影响已得到广泛研究，但对于它们的相互作用却知之甚少，而且对成熟树木和更高营养级的长期研究极为罕见。在这里，我们展示了北美分布最广的树种——颤杨的证据，表明二氧化碳和臭氧单独及联合作用，会影响生产力、叶片的物理和化学防御，并且由于植物质量的变化，还会影响昆虫和病害种群。我们的数据表明，二氧化碳和臭氧引起的植物质量和害虫表现变化对植物生长产生反馈作用是可能的。因此，评估全球变化对森林生态系统的影响必须考虑二氧化碳和臭氧对植物表现的相互作用，以及害虫活动增加的影响。
