ISSN:
1573-5036
Keywords:
Ash application
;
mineral formation
;
mineral weathering
;
Pinus nigra (Arnold)
;
Pinus sylvestris (L.)
;
pyrite
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Lignite and pyrite contents in the dump materials of the Lusatian opencast mining district in East Germany result in high acidification and salinization potentials. These extreme conditions require considerable amounts of alkaline materials like ash or lime to enable recultivation and revegetation. Investigations at chronosequence sites on different mining substrates show characteristic developments of the soil solution chemistry. Processes like weathering of primary and formation of secondary mineral phases, acid production and buffering, and their impacts on both the solid and the liquid soil phase result in high temporal and spatial dynamics especially in the initial phase of soil and ecosystem development. To study these processes we continuously collected soil solutions from different soil depths at seven sites with two representative soil substrates. All sites were afforested with pine and cover stand ages from 1 to 60 yr. The results show that actual pyrite oxidation occurs at the youngest sites on lignite and pyrite containing substrates leading to extremely low pH values and high Fen+ and SO4 2- concentrations. The considerable acid production causes weathering of aluminium silicates resulting in high Aln+ concentrations. Ca2+ concentrations are unexpectedly high even at low pH showing no correlation to amelioration amounts or depths. Therefore it seems most probable that these mining substrates contain geogenic Ca sources. The transport of dissolved weathering products is limited due to low leaching rates enabling formation of secondary phases which control the actual composition of the soil solution. Depth gradients of the soil solution composition at the chronosequence sites point to a gradual transport and leaching of these secondary phases from the soil profiles. Soil solution composition and dynamics at lignite and pyrite free sites show completely different patterns and have a higher potential for successful sustainable recultivation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004542205087
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