Soil aluminium forms and acidification in selected mountainous regions of Bohemia

Forest decline in North-Bohemian mountains have been attributed to soil aci dification caused by acid deposition and consequent release of toxic Al for ms in soil. This study was aimed at the comparison of soil acidification in dices among mountainous regions of Krusne hory and Jizerske hory in Norther n Bohemia and Sumava region in Southern Bohemia. Soil pH, exchangeable acid ity, organic carbon content, humus quality, labile and organically bound Al content, potential cation exchange capacity, base saturation and content o f major base cations (Ca, Mg, and K) were determined in both forest and gra ssland soil samples from the three areas. it was shown that the acidificati on rate generally followed the order Jizerske hory > Sumava > Krusne hory. Principal cause of soil acidification was forest vegetation. Acidification and Al release were intensified by high precipitation and leaching. Differe nces among the areas caused by anthropogenic soil acidification were not pr oved.