Life in the Polar Terrestrial Environment with a Focus on Algae and Cyanobacteria*

Conservation Cryobiology........................................................................................140 Acknowledgments ..........................................................................................................................142 References ......................................................................................................................................143

This review pertains to the coldest regions on Earth, highlighting the importance of applying a fundamental knowledge of in vivo “life in the frozen state.” An overview of the geographical, ecological, and physiological properties of the polar terrestrial environment and polar biodiversity is presented. Emphasis is placed on the central importance of low temperature status and water availability and the way in which these factors affect terrestrial polar habitats and define the life therein. The first part provides a general account of polar environmental research and biodiversity. Exemplar studies of selected permanent residents of Arctic and Antarctic terrestrial ecosystems (algae, higher plants, insects, and arthropods) provide an excellent opportunity for applied lowtemperature biologists to explore extreme survival strategies and adaptive responses, thus offering unique insights into how life tolerates and endures the “frozen state” in vivo. The second part specifically focuses on physiological and biochemical adaptive responses in selected, terrestrial polar biota, and particularly algae and cyanobacteria. The chapter concludes by discussing the present and future potential uses of polar research in applied cryobiology.