Effects of soil macrofauna on other soil biota and soil formation in reclaimed and unreclaimed post mining sites:: Results of a field microcosm experiment

The effect of macrofauna on soil organic matter accumulation (carbon and nitrogen content in the soil), soil hydraulic properties (water holding capacity, water field capacity and wilting point), microbial respiration, microbial biomass, composition of microbial community (using PLFA) and density of soil mesofauna was studied in a field microcosm experiment. Microcosms were located in two sites, either in a reclaimed or unreclaimed, naturally revegetated post mining site, in the Sokolov brown-coal mining area (Czech Republic) for 1 and 3 years. Both sites were located on tertiary clay material; the reclaimed site was covered by a 20-30-year-old alder (Alnus glutinosa and A. incana) plantation; the non-reclaimed site was about 20 years old and covered by shrubs dominated by Salix caprea. The field microcosms consisting of litter (autochthonous litter) and mineral (tertiary clay from a pioneer site) layer were exposed on these sites for 1 and 3 years. The microcosms were either accessible or non-accessible to soil macrofauna. The access of soil macrofauna did not increase significantly carbon mineralization (the loss of organic matter from the whole microcosms) but increased the translocation of organic matter into the mineral layer. This effect seemed to be more pronounced in the reclaimed site. Accumulation of organic matter in the mineral layer resulted in higher microbial respiration and biomass and in increased water retention in the soil. It is considered that these effects correspond with litter fragmentation and soil mixing by soil saprophagous macrofauna. (c) 2005 Elsevier B.V. All rights reserved.