Field research on the effects of UV-B filters on terrestrial Antarctic vegetation

Patches of vegetation of six common species growing on Leonie Island (67 degrees 35' S, 68 degrees 20' W), Antarctic Peninsula region were covered with either UV-B transparent perspex screens or UV-B absorbing screens. Uncovered plots served as a control. Temperature and relative humidity were monitored during the austral summer under and outside the screens. The mean effective PSII quantum efficiency showed significant differences among the species, but not between the UV-B treatments. It was concluded that the temperature and the moisture status of the vegetation obscured any possible influence of UV-B treatment on the tteffective PSII quantum efficiency. he usefulness of various UV-B exclusion and supplementation methods used to study the influence of UV-B in the field is discussed. [KEYWORDS: alga; Antarctica; grass; lichen; moss; ozone depletion; photosynthetic efficiency; UV-B filters; UV-B radiation; UV-B supplementation Ultraviolet-b; chlorophyll fluorescence; active radiation; bean-plants; growth; photosynthesis; irradiances; ozone