Environment and man around Lakes Dńba and Pelesa, SE Lithuania, during the Late Glacial and Holocene

Interdisciplinary investigations (pollen and diatom analysis, 14 C dating and geological-geomorphological and archaeological data) around Lakes Duba and Pelesa, in SE Lithuania, have elucidated the environmental history and human impact throughout the Late Glacial and Holocene. Aerial photograph interpretations indicate that both lakes are residual basins of one Post-Glacial palaeolake outside the morainic relief of the Nemunas (Weichselian) Glaciation. Pollen assemblages from lacustrine deposits date back to the Older Dryas (Lake Duba) and Allerod (Lake Pelesa) and cover all chronozones of the Post-Glacial. Diatom analysis has illustrated the palaeoecological conditions in the lakes and helped reconstruct successive water levels throughout the last 12300 radiocarbon years. Diatom abundance and the distribution of the planktonic, benthic and epiphytic species suggest a lowering of Lake Duba and Lake Pelesa at (e.g.) 11900-10900 14 C BP, (e.g.) 10000-8100 14 C BP and (e.g.) 3700-2500 14 C BP. Pollen data suggest that the earliest signs of human impact and local forest clearances data from about (e.g.) 8400-8300 14 C BP. The first record of cereal pollen in sediments dates from earlier than (e.g.) 6000 14 C BP. Therefore, agriculture was introduced into the area not earlier than the second half of the Midle Neolithic, at about (e.g.) 5000-4400 14 C BP. Continous indications of agriculture and progressive clearing of woodland is consistent with the increasing role of a farming economy during the Bronze Age. Since the 1800-1900 14 C BP formation of an open canopy, increasing soil erosion and changes in vegetation emphasize the remarkable human impact on the environment.