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Title: ATMOSPHERIC RADIOCARBON FOR THE PERIOD 1910–2021 RECORDED BY ANNUAL PLANTS
ABSTRACT We present a timeseries of14CO2for the period 1910–2021 recorded by annual plants collected in the southwestern United States, centered near Flagstaff, Arizona. This timeseries is dominated by five commonly occurring annual plant species in the region, which is considered broadly representative of the southern Colorado Plateau. Most samples (1910–2015) were previously archived herbarium specimens, with additional samples harvested from field experiments in 2015–2021. We used this novel timeseries to develop a smoothed local record with uncertainties for “bomb spike”14C dating of recent terrestrial organic matter. Our results highlight the potential importance of local records, as we document a delayed arrival of the 1963–1964 bomb spike peak, lower values in the 1980s, and elevated values in the last decade in comparison to the most current Northern Hemisphere Zone 2 record. It is impossible to retroactively collect atmospheric samples, but archived annual plants serve as faithful scribes: samples from herbaria around the Earth may be an under-utilized resource to improve understanding of the modern carbon cycle.  more » « less
Award ID(s):
1919506 2224776 1636476
PAR ID:
10474739
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
-
Date Published:
Journal Name:
Radiocarbon
Volume:
65
Issue:
2
ISSN:
0033-8222
Page Range / eLocation ID:
357 to 374
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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