Regional variations of carbonates in postglacial sediments and response of physical sediment properties to climatic events and vegetation

  • Gedminiene L. 1
  • Druzhinina O. 2
  • Stancikaite M. 1
  • 1 Nature Research Centre, Akademijos Str. 2, LT-08412, Vilnius, Lithuania
    2 Shirshov Institute of Oceanology, Russian Academy of Science, 36, Nahimovskiyprospekt, Moscow, Russia, 117997/Herzen University, 48, Nab. Mojki, Saint-Petersburg, Russia, 191186
Keywords: lake sediments, organic matter, carbonates, conifers, postglacial palaeoenvironmental changes, redox conditions.

Abstract

Despite an increasing number of geochemical and palynological data representing the Lateglacial and Holocene sediment sequences that are used to evaluate long-term and short-term interactions between soil and vegetation, the main environmental drivers of these processes are not fully understood so far. Soil composition, vegetation and lake evolution are diverse in all sites analysed in this study. The work was aimed to provide a comparison of the evolution of conifer and broad-leafed plant taxa spread with sediment geochemical data, including organic carbon and CaCO3 changes during the same sedimentation period. Problems addressed here analyze the increased carbonate mobility initiated by the invasion of conifers and a subsequent drop in soil pH. Together with this, the influence of organic material on accumulation of carbonates and sensitivity of Mn and Fe to redox conditions was evaluated. In general, chronologically defined changes in sediment composition revealed the intervals of more stable environmental conditions during which biotic factors were of greater importance in altering vegetation structure and the periods during which scarce vegetation had a negative impact on soil development leading to its progressive deterioration. Related changes occurred in sediments from different lakes; however, due to geographical position, responses to warming or cold events were a bit asynchronous.
Published
2020-08-27
Section
Articles