Tracking human impact in a mining landscape using lake sediments: A multi-proxy palaeolimnological study

Abstract

Mining and metallurgy have caused vast devastation of the landscape in the past and left its legacy on terrestrial and aquatic ecosystems all over the world. Lake sediments provide a continuous record for tracking and better understanding of human-environment interactions related to historical mining and metallurgical activities. Here, we present the analysis of pollen, diatom, cladoceran and chironomid record combined with 210Pb dating, lithology and organic content of the sediments of Velka Richnava reservoir, located in an area intensively mined for polymetallic ores since the end of the 11th century (Banska Stiavnica region, Central Europe). Our aim was to reconstruct the changes in the vegetation cover in the catchment and aquatic biota initially caused by mining and after its cessation by changed management practices. Pollen analysis suggests an open landscape shaped by different land-use during and after the period of active mining toward increased grazing pressure and nutrient input and later to extensive urbanization and spontaneous tree and shrub succession on abandoned grasslands. Shifts in aquatic biota clearly distinguished the phase when the reservoir was used as hydraulic-power source for mining/metallurgy, characteristic by dynamic sedimentation and unstable hydrology from the post-mining period suggesting stabilized hydrology, developed littoral and nutrient enrichment, and later intense urbanization. Our study shows that sediments of man-made reservoirs have a great potential for palaeoecological reconstructions and can extend the current knowledge of past changes in mining landscapes that are rarely described in historical documents.