PHYSIOLOGICAL AND MORPHOLOGICAL CHANGES IN YOUNG WOODY PLANTS STRESSED BY DROUGHT

Woody species have already threatened with drought during handling before planting out but also after planting because of ever more frequent periods of drought. The aim of this study was to consider chosen morphological and physiological parameters of European beech and Norway spruce stressed by drought during one year after planting. Bare-rooted and containerized plants were exposed with desiccation for 0-28 hours and planted. Vitality of plants was evaluated, chlorophyll fluorescence (Fv/Fm), size of needles and leaves and terminal increment were measured. Acute stress by drought before planting caused only small changes of chlorophyll fluorescence even 5 weeks after planting, amounts of vital plants were more than 90% even after 3-4 hours of desiccation before planting. There was registered an extremely low total precipitation during vegetation season, that caused high mortality of containerized plants and higher mortality bare-rooted plants exposed to desiccation before planting. Stress of drought didn't cause a decrease of the terminal increment either the size of needles and leaves. The chlorophyll fluorescence (Fv/Fm) of survived stressed plants was high, higher than at plants that didn't stressed by desiccation. We recommend bare rooted plants with careful handling before planting at sites threatened by drought.