Seasonal Variation in Sources of Dissolved Organic Carbon in a Lacustrine Environment Revealed by Paired Isotopic Measurements (Δ14C and δ13C)
Seasonal Variation in Sources of Dissolved Organic Carbon in a Lacustrine Environment Revealed by Paired Isotopic Measurements (Δ14C and δ13C)
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DOI：
10.1017/s0033822200042648
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发表时间：
2007
期刊：
影响因子：
8.3
通讯作者：
F. Nara;A. Imai;M. Yoneda;K. Matsushige;Kazuhiro Komatsu;T. Nagai;Y. Shibata;Takahiro Watanabe
中科院分区：
文献类型：
--
作者：
F. Nara;A. Imai;M. Yoneda;K. Matsushige;Kazuhiro Komatsu;T. Nagai;Y. Shibata;Takahiro Watanabe
为了研究湖泊环境中溶解有机碳(DOC)的来源和循环，对日本中部以富营养化和浅水湖(平均水深4.0m)著称的鹿儿湖及其支流河流进行了DOC中14C和13C的同位素测量。2003年春季和秋季(5月和9月)采集了湖泊和河流的样品。Δ14C的测量是使用日本国家环境研究所的加速器质谱仪进行的。9月份，DOC值较轻(约为−200%)，湖泊和河流水样的DOC值没有明显差异，表明鹿儿湖及其支流河流的DOC14C年龄比湖水停留时间预期的年龄(平均200d)要早。这一结果表明，陆源是Kasumigaura湖DOC的重要贡献因素。而δ13C值表明，春季湖水DOC值主要是原生的。因此，Kasumigaura湖DOC的来源和循环可能会随季节而变化。
To investigate the sources and cycling of dissolved organic carbon (DOC) in a lacustrine environment, isotopic measurements of 14C and 13C in DOC were carried out for Lake Kasumigaura—which is famous as a very eutrophic and shallow (mean depth 4.0 m) lake in central Japan—and its tributary rivers. Lake and river samples were collected in the spring and autumn (May and September) of 2003. The Δ14C measurements of DOC were performed using the accelerator mass spectrometer at the National Institute for Environmental Studies (NIES-TERRA), Japan. In September, the 14C values of DOC were light (around −200%) and did not differ significantly between lake and river water samples, indicating that DOC in Lake Kasumigaura and its tributary rivers yields older 14C ages than the age expected from the lake-water residence time (average 200 days). This result suggests that terrestrial sources are important contributors to DOC in Lake Kasumigaura. Nevertheless, δ13C values indicated that during spring, DOC in the lake is mainly autochthonous. Thus, sources and cycling of DOC in Lake Kasumigaura may vary seasonally.