Abstract

Deschampsia antarctica and Colobanthus quitensis are usually covered by snow from April to November. It is unknown whether the leaves survive ice encasement. This study proposes that day length influences sugar distribution in C. quitensis and that sugar accumulation favors re-growths after an ice encasement period. The objectives of this work were: (1) to study the effect of day length and low temperature on sugar distribution in organs of C. quitensis and (2) to study the survival and recovery of D. antarctica and C. quitensis after a period of ice encasement. Extremely short day length (SD) (8/16 h) and long day length (LD) (21/3 h) was used, medium (MD) (16/8 h) corresponding at control day length. Also two temperatures: 4°C (cold acclimated) and 15°C (control) were evaluated. Both factors: day length and cold acclimation significantly affected sugar distribution in C. quitensis. Both species presented a high rate of survival after ice encasement. D. antarctica conserved most of their leaves green, while C. quitensis presented dead leaves and new shoots in plants from cold acclimated under SD. Only in D. antarctica the number of green leaves after ice encasement was positively correlated with sugar content in underground organs. The high sugar content in green leaves of both species suggested fast activity recovery after snow melting. © 2008 Springer-Verlag.