Environmental influence on forest development and decline in the Warta River valley (Central Poland) during the Late Weichselian

At Koźmin Las, in the Warta River basin, Central Poland, a series of well-preserved tree trunks and in situ stumps, accompanied by organic deposits, all of Alleröd/Younger Dryas age, have been the focus of a multiproxy palaeoecological study using pollen, plant macrofossil, Cladocera and Chironomidae based on absolute radiocarbon dating. This is the first study to use a dendrological approach to Late Weichselian palaeoenvironmental reconstructions in Central Poland. This study reveals a series of short terrestrial events interrupted by flood episodes in response to climate cooling and provides new opportunities for research into the economic adaptation of Late Palaeolithic hunters to changes in the local environment. Evidence from dendrological studies shows that the riparian forest consisted predominantly of pines of a maximum age of about 140 years and an average age of 68 years. A local pine chronology spanning 133 years has been constructed. The forest appears to have been destroyed ca. 12,600 cal BP by deteriorating hydrological conditions or a sudden catastrophic event (strong wind ?) related to climatic change.