Matric effects contribute less to the water potential of soils in the McMurdo Dry Valleys of Antarctica (informally known as the Ross Desert) than do the mineral salts of these soils. Since soil samples from the same area can exhibit 10-fold differences in mineral content, it is important that water potentials be determined on the same samples used for microbiological unvestigations. The psychrophilic yeast content of fertile soil samples from the arid highlands of the McMurdo Dry valleys indicated that the effective water content of these soils did not exceed ca. 4.5% (v/w).

** Samples were numbered to indicate the austral summer season (p.e. A801=austral ummer of 1980-1981) and the site number (p.e- ...28) followed by an indication of depth at which the sample was taken.

Supplement to: Klingler, J M; Vishniac, Helen S (1988): 3.4 Water potential of Antarctic soils. Polarforschung, 25(2/3), 231-238