PALEOECOLOGY OF A LATE ALLEROD PEAT BED AT GODOY, WESTERN NORWAY

A peat bed found under solifluction deposits on Godoya island, western Norway, accumulated during a few decades around 11 000 yr BP, at the end of the Allerod period of the Late Weichselian. Palaeoecological investigations showed a local vegetation succession on wet sand culminating in a mire community dominated by Carex nigra. Periodic flooding brought in sand and silt, which decreased as drainage was impeded sufficiently for standing water to develop. The surrounding terrestrial vegetation was dominated by Salix scrub, with some open heath and alpine habitats nearby. Apart from two aquatic species, the 29 insect taxa recorded are characteristic of alpine heaths, plant litter (under Salix scrub) and stream-sides. Their remains, together with the terrestrial plant macrofossils, were washed into the mire from nearby. Because the fossils are locally derived, the environmental reconstructions are of the actual conditions at Godoy at ca. 11 000 yr BP. Palaeotemperature estimates from beetles and plants are in agreement. The coleopteran estimates (Mutual Climatic Range Method) suggest mean July temperatures of 10-13-degrees-C, slightly cooler than today (13.5-degrees), and january temperatures between +1 and -10-degrees-C, similar to or much colder than today. Summer temperature estimates from individual plant taxa indicate that temperatures during the Allerod period were similar to today's, but estimates from the reconstructed vegetation and timber-line positions give estimates up to 3.5-degrees cooler. Temperatures fell 2.5-7.5-degrees-C at the Younger Dryas. This abrupt and severe cooling initiated the solifluction processes on Godoya that buried the peat. The Godoy peat bed and its contained fossils provide a rare glimpse of Allerod biota and environments at the local (site) scale.