Dehydration tolerance and water vapour absorption in two species of soil-dwelling Collembola by accumulation of sugars and polyols

Abstract

1. Physiological and biochemical responses to desiccation were studied in two species of hygrophilic Collembola, Folsomia fimetaria L. and Protaphorura armata Tullberg. The temporal changes in water content, body fluid osmotic pressure, and accumulation of sugars and polyols during desiccation stress, equivalent to severe soil drought are reported. 2. Both species initially lost about 50% of their initial content of osmotically active water. Within 7 days F. fimetaria had re-established their preliminary water content by absorbing water vapour from the atmosphere. Protaphorura armata also significantly increased their water content over the following 10 days. 3. Both species were able to resume their hyperosmotic status relative to the desiccating environment they were placed in. The accumulation of myo-inositol and two other unidentified compounds (F. fimetaria) and trehalose (P. armata) made an important contribution to this phenomenon. 4. These results suggest that water vapour absorption by accumulation of sugars and polyols may be widespread in soil-dwelling Collembola.