Development of air pollutant deposition, soil water chemistry and soil on Šerlich research plots, and water chemistry in a surface water source

Abstract

  In 1986 (1987) research plots were established in a forest stands on the south-western slope of Šerlich Mt., Orlické hory Mts. (Kristina Colloredo-Mansfeld – Forest Administration Opočno), at the altitude of 950 to 970 m, to study deposition, chemistry of precipitation and soil water and development of soil chemistry. The plots were established on a clear-cut area, in a young stand and a mature stand of spruce, in a mature beech stand, and in an advanced growth of spruce and European mountain ash. The content of solutes in creek water was studied at the same time. Since 1993 the concentration of substances in precipitation water intercepted in the summit part of Šerlich Mt. has been measured. Research on water chemistry in the stands terminated in 1997. Soil analyses were done in 1986 (1987), 1993 and 1999. The load of acid air pollutants in these forest ecosystems was high in the eighties. After 1991 the deposition of H<sup>+</sup>, S/SO<sub>4</sub><sup>2–</sup>, N/NO<sub>3</sub><sup>– </sup>+ NH<sub>4</sub><sup>+</sup>, Mn, Zn, Al decreased. Similarly, an increase in pH was observed in soil water, and the concentrations of SO<sub>4</sub><sup>2–</sup>, and N, Al compounds decreased. But in 1993 the concentrations of SO<sub>4</sub><sup>2–</sup> and Al increased again under the spruce stand for several months. The concentrations of NO<sub>3</sub><sup>–</sup>, Mn, Zn and Al in the stream water also gradually decreased in the nineties. On the contrary, the average values of S-ions increased compared to those of 1987 to 1991. Strongly acid soil reaction developed in deeper layers until 1993. In the second half of the nineties the pH/H<sub>2</sub>O value somewhat increased again, however the reserve of K, Mg, Ca available cations in the mineral soil constantly decreased. The saturation of sorption complex by basic cations in the lower layer of rhizosphere did not reach even 10% in 1999. The forest ecosystems of Šerlich Mt. were also loaded by a high fall-out of Pb, and increased fall-out of Cu. The lack of balance of N-compound transformations and consumption in the soil and increased leaching of N in the form of nitrates contribute to soil acidification on the investigated plots.