AN INVERSE RELATION BETWEEN FROST SURVIVAL AND ATMOSPHERIC-PRESSURE

Frost resistance generally increases with the altitude of the source population as an adaptive response to lower temperatures. But for a population from a single source, mortality would be expected to increase with altitude when freezing temperatures increase in frequency and intensity. Five species of plants and two species of vertebrates showed increased survival with altitude, given similar freezing temperatures. For lettuce seedlings this increase is highly significant. This evidence, together with laboratory experiments on four species of plants suggest that survival after freezing may increase under low atmospheric pressure. Such a relation is unknown in the literature. If confirmed, it could change our understanding of freezing physiology and have practical applications in diverse fields.