Nitrogen isotope analyses of reindeer (Rangifer tarandus), 45,000 BP to 900 BP: Palaeoenvironmental reconstructions

作者：Stevens Rhiannon E^*; Jacobi Roger; Street Martin; Germonpre Mietje; Conard Nicholas J; Muenzel Susanne C; Hedges Robert E M

来源：Palaeogeography, Palaeoclimatology, Palaeoecology, 2008, 262(1-2): 32-45.

DOI：10.1016/j.palaeo.2008.01.019

• isotope
• nitrogen
• palaeoclimate
• palaeoenvironment
• reindeer
• bone

Pleistocene faunal delta(15)N variations are thought to reflect changes in climatic and environmental conditions. Researchers are still unclear, however, which climatic/environmental parameter is the primary control on Pleistocene faunal delta(15)N values. Through extensive nitrogen isotope analysis of Late Pleistocene reindeer (Rangifer tarandus) collagen we investigated whether permafrost development during the Late Pleistocene coincided with changes in delta(15)N values. After 45 ka BP reindeer delta(15)N declined, with lowest delta(15)N values observed after the Last Glacial Maximum (LGM), between 15 and 11 ka BP. The decline in delta(15)N appears to be of a greater magnitude in more northern regions than in the South of France, a pattern similar to that previously observed for horse. On a global scale, ecosystem delta(15)N is controlled by the relative openness of the nitrogen cycle, which in turn is controlled by climate. Low soil and plant delta(15)N are observed in cold and/or wet regions and high delta(15)N are seen in hot and/or and areas. The regional pattern in reindeer delta(15)N decline mimics the pattern of climatic deterioration in Europe culminating at the LGM, with climate cooling being more intense in northern Europe than in southern Europe. However, the lowest reindeer delta(15)N values are observed after temperatures started to rise. This may have been due to a lag in the response of the nitrogen cycle to increasing temperatures. Alternatively it may have been linked to the influence of permafrost degradation on soil and plant delta(15)N and thus faunal delta(15)N. The renewed climatic cooling during the Younger Dryas did not see a fall in reindeer delta(15)N. Limited data does, however, suggest a post Younger Dryas depletion in reindeer delta(15)N values.

• 出版日期2008-5-27