Multiproxy evidence for terrestrial and aquatic ecosystem responses during the 8.2 ka cold event as recorded at Højby Sø, Denmark |
| |
| Authors: | Mikkel Ulfeldt Hede Peter Rasmussen Nanna Noe-Nygaard Annemarie L Clarke Rolf D Vinebrooke Jesper Olsen |
| |
| Institution: | aDepartment of Geography and Geology, Geology Section, University of Copenhagen, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark;bGeological Survey of Denmark and Greenland, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark;cAPEM (Aquatic Scientists) Ltd, Riverview, A17 Embankment Business Park, Heaton Mersey, Stockport SK4 3GN, UK;dDepartment of Biological Science-Freshwater Biodiversity Laboratory, University of Alberta, Edmonton, Alberta, Canada T6G 2E9;eDepartment of Earth Science, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Aarhus, Denmark |
| |
| Abstract: | A sediment succession from Højby Sø, a lake in eastern Denmark, covering the time period 9400–7400 cal yr BP was studied using high-resolution geochemistry, magnetic susceptibility, pollen, macrofossil, diatom, and algal pigment analysis to investigate responses of the terrestrial and aquatic ecosystems to the 8.2 ka cold event. A reduced pollen production by thermophilous deciduous tree taxa in the period c. 8250–8000 cal yr BP reveal that the forest ecosystem was affected by low temperatures during the summer and winter/early-spring seasons. This finding is consistent with the timing of the 8.2 ka cold event as registered in the Greenland ice cores. At Højby Sø, the climate anomaly appears to have started 200–250 yr earlier than the 8.2 ka cold event as the lake proxy data provide strong evidence for a precipitation-induced distinct increase in catchment soil erosion beginning around 8500 cal yr BP. Alteration of the terrestrial environment then resulted in a major aquatic ecosystem change with nutrient enrichment of the lake and enhanced productivity, which lasted until c. 7900 cal yr BP. |
| |
| Keywords: | 8 2 ka cold event Lake sediments Palaeoclimate Pollen Macrofossils Geochemistry Algal pigments Diatoms Holocene Denmark |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
