Niemi Riikka, Martikainen Pertti J, Silvola Jouko, Sonninen Eloni, Wulff Anu, Holopainen Toini
Department of Ecology and Environmental Science, University of Kuopio, PO Box 1627, FIN-70211 Kuopio, Finland.
Department of Environmental Sciences, Bioteknia 2, University of Kuopio, PO Box 1627, FIN-70211 Kuopio, Finland.
New Phytol. 2002 Dec;156(3):509-515. doi: 10.1046/j.1469-8137.2002.00532.x.
• The flux of ultraviolet (UV)-B radiation to the Earth's surface is increasing, particularly in high latitudes. We studied the sensitivity of some dominant plant species of boreal and subarctic peatlands to this increase. • Intact peat monoliths with the mosses Sphagnum balticum and Sphagnum papillosum, and cotton grass (Eriophorum vaginatum) were exposed to ambient solar UV-B or ambient solar UV-B supplemented by 30% in a field experiment in central Finland. • Although the UV-B dose was low during the growing season, owing to frequent cloudiness, both Sphagnum species showed significantly higher membrane permeability under enhanced UV-B. In S. balticum, UV-B tended to decrease the capitulum dry mass and induced a 30-40% increase in the concentration of chlorophyll and carotenoid pigments. Enhanced UV-B had no effects on leaf morphology, chlorophyll fluorescence or stomatal functioning in E. vaginatum. • The various UV-B responses in the Sphagnum species under investigation indicate that they may be sensitive even to small increases in solar UV-B radiation. By contrast, E. vaginatum appeared to tolerate the UV-B fluxes of the experiment.
• 到达地球表面的紫外线B（UV-B）辐射通量正在增加，尤其是在高纬度地区。我们研究了北方和亚北极泥炭地的一些优势植物物种对这种增加的敏感性。
• 在芬兰中部的一项田间试验中，将带有波罗的海泥炭藓、乳头泥炭藓和棉花草（羊胡子草）的完整泥炭土块暴露于环境太阳UV-B或补充30%的环境太阳UV-B下。
• 尽管生长季节的UV-B剂量较低，由于频繁多云，但两种泥炭藓在增强的UV-B下均表现出显著更高的膜通透性。在波罗的海泥炭藓中，UV-B倾向于降低头状体干质量，并使叶绿素和类胡萝卜素色素浓度增加30 - 40%。增强的UV-B对羊胡子草的叶片形态、叶绿素荧光或气孔功能没有影响。
• 所研究的泥炭藓物种的各种UV-B反应表明，它们甚至可能对太阳UV-B辐射的小幅增加敏感。相比之下，羊胡子草似乎能耐受实验中的UV-B通量。
