Root frost tolerance, seasonal variation in root growth, and field performance of one-year-old Russian larch seedlings with simulated root freezing damages

Planting healthy seedlings with optimal growth potential is essential for proper and survival in forest regeneration. Assessing the seedling quality prior to planting therefore important. In this Icelandic study, effects of root damage induced artificial freezing young Russian larch were examined using capacity method (RGC). Frost tolerance roots varied during winter, undamaged fluctuated, indicating seasonal variations rhythm. The LT50 value frost was −13.9°C late January, but already at −10.6°C (LT10) damages severe. After one growing season, shoot elongation significantly lower frozen −9°C, −13.5°C, −15.5°C by 23%, 54%, 72%, respectively, compared seedlings. Control −9°C achieved 100% after first season. Survival −13.5°C 85% 27%, respectively. second decreased all frost-damaged ongoing mortality demonstrates long-lasting damaged systems, fluctuation winter emphasises need care when are moved outdoor storage.