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Titel |
Comment on "Possible source of ancient carbon in phytolith concentrates from harvested grasses" by G. M. Santos et al. (2012) |
VerfasserIn |
L. A. Sullivan, J. F. Parr |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 2 ; Nr. 10, no. 2 (2013-02-12), S.977-980 |
Datensatznummer |
250017513
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Publikation (Nr.) |
copernicus.org/bg-10-977-2013.pdf |
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Zusammenfassung |
Santos et al. (2012) address the important issue that 14C dating of the
carbon occluded in silica phytoliths (PhytOC) isolated from contemporary
plant materials can produce ages that are incompatible, being often several
kyr older, with both their known recent origin and the 14C age of the
bulk plant material. In their article, Santos et al. (2012) propose that the
anomalously old 14C carbon dates of PhytOC from harvested plant
materials are based on plants taking up "old" dissolved soil carbon to the
plant by roots during nutrient uptake. They then propose that this old
soil-derived carbon is subsequently partitioned from the general plant
biomass into either the silica phytoliths they produce or as recalcitrant
organic matter elsewhere in the plant. We suggest that the full data
available for PhytOC 14C dating do not support this hypothesis. Santos
et al. (2012) also address the important issue of contamination of PhytOC by
general plant biomass material that can occur with procedures that
incompletely extract phytoliths. Whilst we agree that such contamination
needs to be avoided when examining the nature of PhytOC, we also point out
that the converse problem, i.e. removal of PhytOC by over-vigorous extraction
procedures, can also have important adverse consequences. |
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