Nitrogen isotopes suggest a change in nitrogen dynamics between the Late Pleistocene and modern time in Yukon, Canada
| Autor: | Fred J. Longstaffe, Grant D. Zazula, Farnoush Tahmasebi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
plant decomposition
010504 meteorology & atmospheric sciences Pedology Arctic ground squirrel lcsh:Medicine Loess Marine and Aquatic Sciences arctic ground squirrel bone collagen 01 natural sciences Biochemistry nitrogen cycling Pleistocene Epoch Megafauna Yukon Territory Squirrels lcsh:Science Mammals Sedimentary Geology Carbon Isotopes Multidisciplinary Quaternary Period δ13C biology Fossils Eukaryota Sciuridae Geology Plants late Pleistocene Vertebrates Collagen Other Environmental Sciences Research Article Freshwater Environments 010506 paleontology Pleistocene Soil Science Rodents Beringia Bone and Bones Suess effect Animals Paleobotany 0105 earth and related environmental sciences Petrology Plant Fossils Nitrogen Isotopes carbon- and nitrogen-isotope vegetation baseline lcsh:R Ecology and Environmental Sciences eastern Beringia Organisms Biology and Life Sciences Paleontology Proteins Aquatic Environments Geologic Time 15. Life on land Bodies of Water biology.organism_classification Diet Lakes Geochemistry Arctic Amniotes Earth Sciences Cenozoic Era lcsh:Q Sediment Physical geography sense organs Paleobiology Collagens |
| Zdroj: | PLoS ONE Earth Sciences Publications PLoS ONE, Vol 13, Iss 2, p e0192713 (2018) |
| ISSN: | 1932-6203 |
| Popis: | A magnificent repository of Late Pleistocene terrestrial megafauna fossils is contained in ice-rich loess deposits of Alaska and Yukon, collectively eastern Beringia. The stable carbon (δ13C) and nitrogen (δ15N) isotope compositions of bone collagen from these fossils are routinely used to determine paleodiet and reconstruct the paleoecosystem. This approach requires consideration of changes in C- and N-isotope dynamics over time and their effects on the terrestrial vegetation isotopic baseline. To test for such changes between the Late Pleistocene and modern time, we compared δ13C and δ15N for vegetation and bone collagen and structural carbonate of some modern, Yukon, arctic ground squirrels with vegetation and bones from Late Pleistocene fossil arctic ground squirrel nests preserved in Yukon loess deposits. The isotopic discrimination between arctic ground squirrel bone collagen and their diet was measured using modern samples, as were isotopic changes during plant decomposition; Over-wintering decomposition of typical vegetation following senescence resulted in a minor change (~0-1 ‰) in δ13C of modern Yukon grasses. A major change (~2-10 ‰) in δ15N was measured for decomposing Yukon grasses thinly covered by loess. As expected, the collagen-diet C-isotope discrimination measured for modern samples confirms that modern vegetation δ13C is a suitable proxy for the Late Pleistocene vegetation in Yukon Territory, after correction for the Suess effect. The N-isotope composition of vegetation from the fossil arctic ground squirrel nests, however, is determined to be ~2.8 ‰ higher than modern grasslands in the region, after correction for decomposition effects. This result suggests a change in N dynamics in this region between the Late Pleistocene and modern time. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
| Nepřihlášeným uživatelům se plný text nezobrazuje | K zobrazení výsledku je třeba se přihlásit. |