(1) To understand through field experimentation, the long term susceptibility of a range of European semi-natural ecosystems to increases in UV-B radiation. (2) To understand how other global change variables (e.g. CO2 concentration, temperature, nutrient and water supply) may affect plant species sensitivity to increases in UV-B radiation. (3) To determine the effects of UV-B radiation on decomposition and hence on nutrient cycling. (4) To determine the effects of UV-B radiation on vegetation dynamics and community structure. (5) To compare plant responses to enhanced UV-B radiation supplied in the solar tracking modulated mode and in the square wave mode.
Methods: Two new field sites will be established (Adventdahlen, Svalbard; Amsterdam, The Netherlands) and
two existing sites will be maintained (Abisko, Sweden; Patras, Greece Supplementation of UV-B radiation will
be suspending UV-B fluorescent tubes over vegetation in situ. This supplementation will involve a stepwise
increase and decrease in daily UV-B radiation simulating a 15% ozone depletion. At one site (Abisko) square
wave and modulated UV-B exposure systems will be compared in a new experiment on an ombrotrophic mire.
Filtration experiments will also be performed at the two sites with highest incident UV-B (Amsterdam and
Patras). Studies of interactions between other global change variables [temperature (Abisko and Adventdahlen),
CO2 (Abisko and Amsterdam), precipitation (Abisko and Patras) and nutrient supply (Patras)] will also be made.
Measurements will include morphological studies of leaf and cuticle thickness, shoot elongation and architecture,
flower and seed production, physiological studies of photosynthesis, fluorescence induction, stomatal
conductance and plant pigment composition, studies of effects on vegetation structure and competitive
interactions, and decomposition studies both in situ and in microcosms. The decomposition studies will include
assessment of microbial population sizes and community structure on one litter per site and will be the
responsibility of Lancaster.
Achievements: The achievements will include data quantifying the vegetation and ecosystem responses to UV-B
at sites covering a wide range of latitudes in Europe, elucidation of the interaction between UV-B and elevated
CO2 (600 ppm), UV-B and temperature, UV-B and precipitation and UV-B and enhanced nutrient supply at
selected sites, and a comparison of square wave and modulated UV-B exposure systems. The long-term nature
of the experiments (up to 7 years in the case of Abisko) should allow the elucidation of the major potential
effects of UV-B on plant and microbial populations, vegetation dynamics and ecosystem processes.
The consortium is one of the few worldwide which focuses on the interactive effects of UV-B and other climate
change variables, and is unique in studying the effects of UV-B and elevated CO2 interactions in situ. The
results should improve predictions of the ecological effects of enhanced UV-B radiation under a range of climate
Funding SchemeCSC - Cost-sharing contracts
221 00 Lund
LA1 4YQ Lancaster
1081 HV Amsterdam