Relationship between Norway spruce status and soil water base cations/aluminum ratios in the Czech Republic

There is a concern that soil acidification by acidic deposition, along with the resulting depletion of the labile pool of nutrient cations (e.g. Ca, M g) and enhanced leaching of Al from soil may contribute to forest dieback. The molar ratios of Ca/Al or (Ca+Mg+K)/Al in the soil solution have been wi dely used as a criterion for risk of tree damage due to acidification. Inte nsity and quality of the crown and branch structure transformation due to f ormation of secondary shoots in successive series is a very sensitive indic ator of long-term tree damage, and the subsequent regenerative processes. S oil water chemistry and crown structure transformation of Norway spruce wer e observed at 16 forest plots within the Czech Republic with the following results: parameters, expressing degradation processes in the crown (defolia tion of primary structure), regeneration processes (percentage of secondary shoots) or synthetic stages of crown structure transformation showed high correlation with soil water (Ca+Mg+K)/Al ratio in organic horizons. No rela tionships were found for mineral horizons. The correlations between soil wa ter and crown status parameters were considerably stronger when using the ( Ca+Mg+K)/Al ratio rather than the Ca/Al ratio.