Abstract
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 order
to 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 various
set-ups have been performed. Activation of plant defence mechanisms by production
of UV-B absorbing compounds was significant in ambient UV-B in comparison to
a filter treatment reducing the UV-B radiation. Despite the UV-B screening response,
ambient UV-B was demonstrated to decrease photosynthesis and shift carbon allocation
from shoots to roots. Moreover, ambient UV-B increased plant stress with detrimental
effects on electron processing in the photosynthetic apparatus. Plant responses
did not lead to clear changes in the amount of fungal root symbionts (mycorrhiza) or in
the biomass of microbes in the soil of the root zone. However, the composition of the
soil microbial community was different in the soils under ambient and reduced UV radiation
after three treatment years. These results provide new insight into the negative
impact of current UV-B fluxes on high-arctic vegetation. They supplement previous
investigations from the Arctic focussing on other variables like growth etc., which
have reported no or minor plant responses to UV-B, and clearly indicates that UV-B
radiation is an important factor affecting plant life at high-arctic Zackenberg. However,
long-time experiments are needed in order to see whether the observed changes
are transient or whether they accumulate over years. Such experiments are especially
important for valid determination of below-ground responses, which potentially lead
to feedbacks on the ecosystem functioning.
| Original language | English |
|---|---|
| Publication date | 2008 |
| Publication status | Published - 2008 |
| Event | Biological responses to current UV-B radiation in Arctic regions - Duration: 29 Nov 2010 → … |
Conference
| Conference | Biological responses to current UV-B radiation in Arctic regions |
|---|---|
| Period | 29/11/2010 → … |