TY - ABST

T1 - Biological responses to current UV-B radiation in Arctic regions

T2 - Biological responses to current UV-B radiation in Arctic regions

AU - Albert, Kristian

AU - N. Mikkelsen, Teis

AU - Ro-Poulsen, Helge

PY - 2008

Y1 - 2008

N2 - Depletion of the ozone layer and the consequent increase in solar ultraviolet-B radiation(UV-B) may impact living conditions for arctic plants significantly. In orderto evaluate how the prevailing UV-B fluxes affect the heath ecosystem at Zackenberg(74°30'N, 20°30'W) and other high-arctic regions, manipulation experiments with variousset-ups have been performed. Activation of plant defence mechanisms by productionof UV-B absorbing compounds was significant in ambient UV-B in comparison toa filter treatment reducing the UV-B radiation. Despite the UV-B screening response,ambient UV-B was demonstrated to decrease photosynthesis and shift carbon allocationfrom shoots to roots. Moreover, ambient UV-B increased plant stress with detrimentaleffects on electron processing in the photosynthetic apparatus. Plant responsesdid not lead to clear changes in the amount of fungal root symbionts (mycorrhiza) or inthe biomass of microbes in the soil of the root zone. However, the composition of thesoil microbial community was different in the soils under ambient and reduced UV radiationafter three treatment years. These results provide new insight into the negativeimpact of current UV-B fluxes on high-arctic vegetation. They supplement previousinvestigations from the Arctic focussing on other variables like growth etc., whichhave reported no or minor plant responses to UV-B, and clearly indicates that UV-Bradiation is an important factor affecting plant life at high-arctic Zackenberg. However,long-time experiments are needed in order to see whether the observed changesare transient or whether they accumulate over years. Such experiments are especiallyimportant for valid determination of below-ground responses, which potentially leadto feedbacks on the ecosystem functioning.

AB - Depletion of the ozone layer and the consequent increase in solar ultraviolet-B radiation(UV-B) may impact living conditions for arctic plants significantly. In orderto evaluate how the prevailing UV-B fluxes affect the heath ecosystem at Zackenberg(74°30'N, 20°30'W) and other high-arctic regions, manipulation experiments with variousset-ups have been performed. Activation of plant defence mechanisms by productionof UV-B absorbing compounds was significant in ambient UV-B in comparison toa filter treatment reducing the UV-B radiation. Despite the UV-B screening response,ambient UV-B was demonstrated to decrease photosynthesis and shift carbon allocationfrom shoots to roots. Moreover, ambient UV-B increased plant stress with detrimentaleffects on electron processing in the photosynthetic apparatus. Plant responsesdid not lead to clear changes in the amount of fungal root symbionts (mycorrhiza) or inthe biomass of microbes in the soil of the root zone. However, the composition of thesoil microbial community was different in the soils under ambient and reduced UV radiationafter three treatment years. These results provide new insight into the negativeimpact of current UV-B fluxes on high-arctic vegetation. They supplement previousinvestigations from the Arctic focussing on other variables like growth etc., whichhave reported no or minor plant responses to UV-B, and clearly indicates that UV-Bradiation is an important factor affecting plant life at high-arctic Zackenberg. However,long-time experiments are needed in order to see whether the observed changesare transient or whether they accumulate over years. Such experiments are especiallyimportant for valid determination of below-ground responses, which potentially leadto feedbacks on the ecosystem functioning.

M3 - Conference abstract for conference

Y2 - 29 November 2010

ER -