title: The evolution of a mining lake - From acidity to natural neutralization.
abstract: Along the border of Poland and Germany (central Europe), many of the post-mining lakes have formed "an anthropogenic lake district". This study presents the evolution of a mining lake ecosystem (TR-33) based on subfossil phyto- and zooplankton, isotopic data (δ(13)C, δ(15)N), elemental analyses of organic carbon and nitrogen (C/N ratio and TOC) and sedimentological analyses. Recently, lake TR-33 became completely neutralized from acidification and an increase in eutrophication began a few years ago. However, the lake has never been neutralized by humans; only natural processes have influenced the present water quality. From the beginning of the existence of the lake (1920s) to the present, we can distinguish four stages of lake development: 1) very shallow reservoir without typical lake sediments but with a sand layer containing fine lignite particles and very poor diatom and cladoceran communities; 2) very acidic, deeper water body with increasing frequencies of phyto- and zooplankton; 3) transitional period (rebuilding communities of diatoms and Cladocera), meaning a deep lake with benthic and planktonic fauna and flora with wide ecological tolerances; and 4) a shift to circumneutral conditions with an essential increase in planktonic taxa that prefer more fertile waters (eutrophication). In the case of lake TR-33, this process of natural neutralization lasted approximately 23years.
authors.affiliation: Institute of Geological Sciences, Polish Academy of Sciences, Research Centre at Warsaw, St. Twarda 51/55, Warsaw PL-00818, Poland. Electronic address: esienkie@twarda.pan.pl.
authors.forename: Elwira
authors.initials: E
authors.lastname: Sienkiewicz
authors.affiliation: Institute of Geological Sciences, Polish Academy of Sciences, Research Centre at Warsaw, St. Twarda 51/55, Warsaw PL-00818, Poland. Electronic address: mgasior@twarda.pan.pl.
authors.forename: Michał
authors.initials: M
authors.lastname: Gąsiorowski
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D033361:Cladocera; D017377:Diatoms; D017753:Ecosystem; D004784:Environmental Monitoring; D005068:Eutrophication; D005858:Germany; D006863:Hydrogen-Ion Concentration; D060106:Lakes / Q000737:chemistry*; D008906:Mining; D009584:Nitrogen; D011044:Poland; D015048:Zooplankton
chemical_list: D009584:Nitrogen
keywords: Artificial mining lake; Cladocera; Diatoms; Natural neutralization; Sediment core