The objective of our work with arctic terrestrial plants and with algae is to study the range of climate adaptation as is expressed in special ultrastructure of cells and tissues, in photosynthetic metabolism, in antioxidative and sun screen compounds under a cold and reduced PAR / UV-B environment (climate different to alpine conditions). This is a comparison of ecophysiological processes already worked out mainly from high alpine plants, which live periodically under stronger cold and under different light regimes, especially higher UV-B and PAR irradiation. We want to find out, whether adaptations found in some alpine organisms occur similarly in polar forms.