Responses of plants in polar regions to UVB exposure : a meta-analysis
This article was originally published as Newsham, KK and Robinson, SA, Responses of plants in polar regions to UV-B radiation : a meta-analysis, Global Change Biology, 15, 2009, 2574-2589. The definitive version is available at www3.interscience.wiley.com
We report a meta-analysis of data from 34 field studies into the effects of UV-B radiation on Arctic and Antarctic bryophytes and angiosperms. The studies measured plant responses to decreases in UV-B radiation under screens, natural fluctuations in UV-B irradiance, or increases in UV-B radiation applied from fluorescent UV lamps. Exposure to UV-B radiation was found to increase the concentrations of UV-B absorbing compounds in leaves or thalli by 7% and 25% (expressed on a mass or area basis, respectively). UV-B exposure also reduced aboveground biomass and plant height by 15% and 10%, respectively, and increased DNA damage by 90%. No effects of UV-B exposure were found on carotenoid or chlorophyll concentrations, net photosynthesis, Fv/Fm or ΦPSII, belowground or total biomass, leaf mass, leaf area or specific leaf area (SLA). The methodology adopted influenced the concentration of UV-B absorbing compounds, with screens and natural fluctuations promoting significant changes in the concentrations of these pigments, but lamps failing to elicit a response. Greater reductions in leaf area and SLA, and greater increases in concentrations of carotenoids, were found in experiments based in Antarctica than in those in the Arctic. Bryophytes typically responded in the same way as angiosperms to UV-B exposure. Regression analyses indicated that the percentage difference in UV-B dose between treatment and control plots was positively associated with concentrations of UV-B absorbing compounds and carotenoids, and negatively so with aboveground biomass and leaf area. We conclude that, despite being dominated by bryophytes, the vegetation of polar regions responds to UV-B exposure in a similar way to higher plant-dominated vegetation at lower latitudes. In broad terms, the exposure of plants in these regions to UV-B radiation elicits the synthesis of UV-B absorbing compounds, reduces aboveground biomass and height, and increases DNA damage.
K. K. Newsham and S. R. Robinson. "Responses of plants in polar regions to UVB exposure : a meta-analysis" Faculty of Science - Papers (2009).
Available at: http://works.bepress.com/srobinson/22