Occurrence and variation in the amount of Characean oospores in Estonian Late-glacial sediments: state of the art and prospectives

The Characeae oospores are frequently found in sediment samples during Quaternary palaecological studies. Counts of oospores of three Estonian Late-glacial (14000 – 11500 calibrated year before present, cal y BP) sediment cores are presented and discussed. The first postglacial findings of Characeae oospores in Estonia date back 13900 cal y BP confirming the early appearance of Characeae in postglacial water bodies. The oospores found in two southern localities belong to Chara spp. while only Nitella spp oospores are counted in lake situated hundred kilometers in North. In general the number of oospores is low, maximum 50 oospores per 100 cm and rises near to the Holocene boundary (11800 cal y BP). The significance and limits of oospore counts for palaeoecological studies are discussed. The studied territory is situated near to the Baltic Sea and has numerous inland lakes offering various possibilities for future applications of Characeae oospore analysis.