Climate and abiotic landscape controls of Younger Dryas environmental variability based on a terrestrial archive (the Żabieniec mire, Central Poland)

Abstract

The global climatic trend of the Younger Dryas is clearly registered in the Greenland ice core archives and is printed in terrestrial biogenic deposits. Abiotic landscape components, too, were subjected to changes. The article aims to indicate the dynamics of geomorphological processes activated in response to the cooling and to detect markers of these processes printed within a core of sediments of lacustrine origin and a lake catchment. The article also aims to quantify the extent to which the climate-influenced palaeobotanical record is correlated with local abiotic determinants. The study site lies in an isolated upland location in an old glacial area. The studies include geomorphological and geological analysis of the Younger Dryas palaeolandscape and studies of biogenic deposits of one of the thickest Younger Dryas lacustrine series in Central Poland using biotic proxies and geochemical analysis. A chronology is provided by an age–depth model based on series of radiocarbon datings. The studies demonstrated that for over a thousand years after the beginning of the Younger Dryas (12,653–11,764 modelled cal BP) environmental changes were gradual and thresholds were not exceeded. The morphogenetic processes intensified at the end of the Younger Dryas (11,764–11,533 modelled cal BP) but they also were not catastrophic. The palaeobotanical record is also gradual and reflects the vegetation cover’s smooth adaptation to global climate changes, with three clear phases of vegetation development. However, the stability of the landscape system was disturbed, as supported by changes in organic life registered in the palaeolake. Traces of wildefires suggest the factor that triggered abiotic processes and affected the biotic sphere. A comprehensive regional case study has shown the importance of tracking local conditions to modify a global approach and will contribute to a better understanding of the complex environmental impact of the Younger Dryas.