Changes in some physical properties of soils in the chronosequence of self-overgrown dumps of the Sokolov quarry-dump complex, Czechia
Abstract
The water-physical properties (bulk density, air conductivity, texture, water content, and temperature dynamics) were studied in a chronosequence of soils developing on self-overgrowing quarry-dump complexes in the area of Sokolov, Czechia. The area overgrown for 12 years was covered by a thin grass cover; osiers were observed after 20 years of overgrowth; a broadleaved forest was found on a plot after 45 years of overgrowth.
The particle-size distribution in the soil was determined using peptization by pyrophosphate and the FAO method. When the soil was prepared by the FAO method, a predominance of physical clay (62-72%) in the dump material was revealed; at the use of pyrophosphate peptization, the content of this fraction was lower (18-19%).
The observed differences can be due to the incomplete degradation of the microaggregates composed of clay particles during the peptization by pyrophosphate. A decrease in the field water content of the soils with the increasing time of the dump's overgrowth was observed.
This could be attributed to the more significant evapotranspiration of the perennial woody vegetation compared to the herbaceous plants, which agreed with the data on the projective cover of plants and their root biomass. A decrease in the soil temperature in the root-inhabited layer (in the diurnal variation) with the age of succession was also observed.
The analysis of the data on the field soil water content and their comparison with the results of the laboratory measuring of the wilting points indicated that the development of plants could be restricted by a water deficit at the 20- and 45-year-old stages of the succession.