Home – Home – Jornals – Contemporary Problems of Ecology 2017 number 6

It is established that in the conditions of cold humid climate the change in the chemical composition of soils after the arrival of volcanic ash in them depends on the granulometric and petrochemical composition of the products of eruptions, the method and the forms of chemical elements entering the soils, the season and the meteorological conditions of the ash falls. Petrochemical composition of ash determines, mainly, the nature of changes in the gross composition of soils. Transformations of soils in the part of the contents of mobile forms depend more on the time of year and the meteorological conditions of ash falls. The overwhelming part (up to 99.3 %) of the mobile forms of most elements enters the soils at ash falls not in the composition of ash particles, but in gas and water-soluble forms directly from the dispersion medium of volcanic aerosol. In 25 km from the centers of eruptions in soils are established: in winter conditions - growth of gross contents of elements and removal of their mobile forms; in the summer period - the accumulation of mobile forms of elements against the background of a fall in the content of their gross forms, acidification of soils is observed here with a significant (about 1.5-fold) decrease in the degree of saturation of soils with bases.