Desiccation and recovery of antarctic cyanobacterial mats

Summary The ability of cyanobacterial mats from Antarctic ponds and streams to recover from desiccation is described. Mats dominated by Nostoc dehydrated rapidly and were dry within 5 h of exposure. Nostoc mats recovered to pre-desiccation rates of photosynthesis and respiration within as little as 10 min of rewetting. Recovery of acetylene reduction activity was slower (>24 h). Phormidium dominated mats were less tolerant of desiccation, and recovery on rewetting from air-drying was not complete after 10 days. Viable diaspores were, however, found in Phormidium mats which had been exposed for 3 years. Partial hydration during aerial exposure improved the survival of Phormidium mats, but appeared to slow the recovery of Nostoc mats on subsequent rewetting.