Assessment of quantitative Holocene temperature reconstructions using multiple proxies from the Lake Loitsana sediment record

摘要: Multiple proxies derived from the Lake Loitsana sediment sequence (NE Finland) are employed to determine timing of deglaciation, characterise an early Holocene proglacial lake stage and reconstruct development. Local-scale processes causing shifts in biological assemblages identified most likely mean July air temperature (Tjul) development is assessed. The study area was deglaciated shortly prior 10 700 cal. a BP. record reflects four local events; presence glacial lake, drainage formation Loitsana, changes fluvial input due progressive wetland expansion, gradual infilling. results suggest that events have driven through various processes, biotic reflect environmental parameters highly individual manner. Furthermore, can themselves act as important drivers, influencing composition other assemblages. It suggested future studies should consider macrophyte abundance food-web interactions equally factors when assessing Quantitative Tjul reconstructions based on display contrasting trends. While pollen found relatively low values, plant macrofossil chironomid data warm summer conditions also during Holocene, i.e. at peak insolation. recorded by terrestrial affected possibly combined with delayed response ecosystem compared aquatic one. This emphasises importance using multiple palaeoenvironmental shows potential drive affect transfer-function reconstructions.