VYHODNOCENÍ ODOLNOSTI K VYSYCHÁNÍ U ZÁKLADNÍCH PŘÍPRAVNÝCH DŘEVIN – BŘÍZY A OSIKY.

The goal of this study is evaluation of the effect of different levels of plant water stress on their subsequent performance in the first growing season after planting. The most noticeable manifestation of current global climate change are more frequent drought periods of greater intensity and different duration. For successful artificial forest restoration, the basic factor is the use of high-quality planting stock showing both morphological quality and desired physiological status. The physiological status of the plants is one of the most important factors predisposing survival rates and growth after planting. For objective evaluation of their water regime a water potential (stress) of plants was measured using the pressure chamber, water content, water deficit and relative electrical conductivity. For the reforestation of large clear cuts, which area is increasing currently, it is necessary to use also artificial renewal using preparatory (pioneer) trees. The results showed that all the methods used to evaluate the physiological quality responded to the stress of silver birch and European aspen seedlings exposed to deliberate drying and corresponded to losses and reduced growth after planting. The birch seedlings were more sensitive to drying when compared to aspen. [ABSTRACT FROM AUTHOR]