Mature Norway spruce (Picea abies [L.] Karst.) stands affected by decline symptoms were selected in the northern part of the Hanušovická highland (Czech Republic) at Jeřáb Mt. foot and summit (1,003 m a.s.l.). Spruce stand (SS) 1 (700 m a.s.l.) was situated in conditions of the fir-beech forest altitudinal zone (FAZ). SS 2 (880–900 m a.s l.) was situated in conditions of the spruce-beech FAZ. Research plots (RPs) of the area 400 m<sup>2</sup> were selected in the stands according to the different level of damage and stand diversity. On the basis of the complex soil analysis it was proved that the soil environment could be a part of stress factors, influencing the predisposition of non-natural Norway spruce monocultures at mountain locations of the Krkonoše Mts.-Jeseníky Mts. elevation. High Al<sup>3+</sup> concentrations in soil mineral horizons were determined in a direct correlation with decline of stand enclaves on the selected RPs. The concentrations of Al<sup>3+</sup> and limiting content Mg<sup>2+</sup> make root systems exist mainly in H-horizons or Ae/Ep-horizons. This causes stand predisposition to climatic drought and drought episodes.
Remote sensing of Japanese beech forest decline using an improved Temperature Vegetation Dryness Index (iTVDI)
