SURVIVAL OF MYCORRHIZA FORMED BY <i>CENOCOCCUM GEOPHILUM</i> FR. IN DRY SOILS

Abstract

SUMMARY Seedlings and 2‐year old saplings of Tilia cordata growing in the shade on sandy‐textured soils can survive periods when the water potential of the soil decreases to −18 to −55 bars. Their mycorrhiza formed by Cenococcum geophilum is shown to remain alive. Measurement of rates of water‐loss from seedlings in similar conditions decreases from 16.0 to 26.2 mg h −1 when the soil is wet, to 4.1 to 4.6 mg h −1 when the soil is dry. Calculation of the volume of the mycorrhiza shows that its water content would support transpiration for periods not exceeding 1 h. Survival of the mycorrhiza through long periods of drought is apparently related to the ability of the fungal partner to withstand desiccation.