Table 3: Reproductive viability of Hemichloris antarctica after cycles of cooling und warming

Laboratory experiments show that undercooling to about -5°C occurs in colonized Beacon sandstones of the Ross Desert, Antarctica. High-frequency temperature oscillations between 5°C and -5°C or -10°C (which occur in nature on the rock surface) did not damage Hemichloris antarctica. In a cryomicrosco...

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Bibliographic Details
Main Authors: Meyer, M A, Huang, G-H, Morris, G J, Friedmann, E Imre
Format: Dataset
Language:English
Published: PANGAEA 1988
Subjects:
Age
Cycles
Range
Standard deviation
Viability
Antarctic
The Antarctic
Antarc*
Antarctica
Polarforschung
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.762488
https://doi.org/10.1594/PANGAEA.762488
Description
Summary:Laboratory experiments show that undercooling to about -5°C occurs in colonized Beacon sandstones of the Ross Desert, Antarctica. High-frequency temperature oscillations between 5°C and -5°C or -10°C (which occur in nature on the rock surface) did not damage Hemichloris antarctica. In a cryomicroscope, H. antarctica appeared to be undamaged after slow or rapid cooling to -50°C. l4CO2 incorporation after freezing to -20°C was unaffected in H. antarctica or in Trebouxia sp. but slightly depressed in Stichococcus sp. (isolated from a less extreme Antarctic habitat). These results suggest that the freezing regime in the Antarctic desert is not injurious to endolithic algae. It is likely that the freezing-point depression inside the rock makes available liquid water for metabolic activity at subzero temperatures. Freezing may occur more frequently on the rock surface and contribute to the abiotic nature of the surface.

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