14C ages and delta13C of sclerotium grains found in forest soils
2007
Watanabe, M.(Tokyo Inst. of Technology, Tokyo (Japan)) | Sato, H. | Matsuzaki, H. | Kobayashi, T. | Sakagami, N. | Maejima, Y. | Ohta, H. | Fujitake, N. | Hiradate, S.
sup(14)C ages and deltasup(13)C were examined for sclerotium grains to elucidate the characteristics of these grains distributed in forest soils. The ages of the grains from surface A horizons and buried A horizons were ca 100-200 BP and ca 300-1,200 BP, respectively. In comparison with humic acid extracts, the sup(14)C ages were in the increasing order: humic acid fraction humic acid Pg fraction sclerotium grains. The deltasup(13)C values for sclerotium grains in surface A horizons and buried A horizons were approximately -31 permille to -28 permille, and these values were approximately 2-4 permille smaller than those of humic acids and soils. The C content of the grains had a tendency to decrease with increasing sup(14)C ages, while the C content of humic acid was constant with age. The sup(14)C ages of sclerotium grains indicate the individual age of grain formation, which are more likely to assign closer ages to the beginning of soil forming than the sup(14)C ages of humic acid. The low deltasup(13)C values for sclerotium grains have presumably originated from characteristically biological organics, which may be protected from attack in soils because of their structure.
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