Freezing resistance of arctic tundra plants on Svalbard

Arctic tundra plants collected from limestone-ridge vegetation on Svalbard (79 N) in summer survived freezing tests to only -2 degrees C or -4 degrees C. In winter, although injured by freezing, species retained capacity to grow after tests to -67 degrees C. Plants also survived -67 degrees C in a simulation experiment with 'continental' conditions where high ambient temperatures caused water stress while soils remained frozen. Most species survived the effects of a simulated warm spring followed by a freeze. Surprisingly there was no difference in cold tolerance of graminoid and cushion-plant herbaceous species.