A multi-century δ 13 C record of the C 4 grass Setaria macrostachya in the US Southwest: Identifying environmental causes of variability
AffiliationUniv Arizona, Geosci Dept
Univ Arizona, NSF Arizona Accelerator Facil
MetadataShow full item record
PublisherELSEVIER SCIENCE BV
CitationEastoe, C., & Toolin, L. (2018). A multi-century δ13C record of the C4 grass Setaria macrostachya in the US Southwest: Identifying environmental causes of variability. Palaeogeography, Palaeoclimatology, Palaeoecology, 489, 129-136.
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AbstractAnnual and 5-year averages of delta C-13 measured on florets of the C-4 grass Setaria macrostachya decreased from -10 to -13 parts per thousand between 1849 and 2016. Atmosphere-plant delta C-13 discrimination (A) changed from 3 to 4 early in this interval, to 4-5 since 1970. These century-scale changes result from decrease in atmospheric delta C-13 and, prior to 1970, from changes in A related to increase in the partial pressure of CO2 in the atmosphere, both largely caused by the burning of fossil fuels. Short-term fluctuations (interannual to decadal) in slope of the time series of averaged delta C-13 do not result from natural causes, but in certain cases appear to coincide with human economic activities. Annual delta C-13 ranges in years with sufficient measurements are consistently about 2 parts per thousand. It is unlikely that useful information on past atmospheric delta C-13 will be obtained from S. macrostachya seeds preserved in packrat middens or other archives.
Note24 month embargo; published online: 13 October 2017
VersionFinal accepted manuscript