Archiwum zmian środowiska naturalnego okresu przełomu plejstocen-holocen w basenie uniejowskim

Archives of changes in the natural environments are gathered in various kinds of sediments, depending on the time in the history of the Earth. The Quaternary environmental variations are recorded from the ocean cores and the Greenland or Antarctic ice cores. High temporal resolution for shorter periods may be derived from annually laminated lacustrine sediments. A versatile archive for palaeogeographical reconstruction of the time of the Pleistocene-Holocene transition in the fluvial system has been found at Koźmin Las site in the Uniejów Basin of the middle Warta river valley. Well-preserved remains of pine subfossil forest as trunks and in situ stumps and accompanying organic deposits, of the late Alleröd and Younger Dryas age, have been subjected to multiproxy palaeoecological analysis and geological investigations. The sediments stored signals of a few short terrestrial events interrupted by periodic floods. It has been concluded that the forest was destroyed by deteriorating hydrological conditions or a sudden catastrophic event, like a strong wind, in response to a global climatic change of the Pleistocene-Holocene transition. The Late Weichselian natural events recorded at the site point to a possible reaction of the fluvial system in a changing climate and environment. The knowledge about the past is essential to the creation of current ecosystem management strategies.