Impacts of climate change on Antarctic vascular plants: warming and UV-B radiation

Our research endeavors fell into the following categories: 1) We conducted a long-term field experiment at Stepping Stones, near Palmer Station, in which we reduced levels of UV radiation and raised air temperatures around naturally growing Deschampsia antarctica and Colobanthus quitensis plants for four consecutive growing seasons.

We examined plant responses to these manipulations by assessing photosynthesis, vegetative growth, cover, and sexual reproduction. At the end of this experiment, we collected plant, soil and litter samples, and examined treatment effects on plant biomass production, litter accumulation, soil properties, and microarthropod populations. 2) Single growing-season experiments were also conducted at Stepping Stones, primarily aimed at examining the influence of UV-B radiation on plant growth processes and concentrations of UV-screening compounds in leaves, and soil seed banks. 3) We also conducted a more intensive short-term experiment at Palmer Station, in which we placed potted plants under UV-B transparent or UV-B absorbing filters from November through late December, corresponding to the ozone depletion/enhanced UV-B season.