呼伦湖沉积物有机碳的分布特征

Characteristics of Organic Carbon Distribution in the Sediment of Hulunhu Lake, China

以内蒙古高原湖泊呼伦湖为对象,开展了湖泊沉积物有机碳的分布特征研究。结果表明:呼伦湖沉积物中总有机碳(TOC)含量范围为9.18～61.68g·kg-1,平均34.64g·kg-1;重组碳(HFOC)含量范围为9.02～61.47g·kg-1,平均34.32g·kg-1;轻组碳(LFOC)含量范围为0.02～0.86g·kg-1,平均0.32g·kg-1。TOC在空间分布上呈现从北西向南东逐渐递减的趋势。表层沉积物中C/N的平均值为20.35,表明呼伦湖中有机质的多源性。

The total organic carbon（TOC） plays an important role in carbon cycles. TOC can be divided into light-fraction organic carbon（LFOC） and heavy-fraction organic carbon（HFOC） using the density fraetionation technique recently, LFOC consists of visible partly decomposed plant material at various stage of decomposition, includes spore, seed, animal and microbial debris and some soil minerals particle associated with plant debris. It is a good indicator for labile organic carbon. And HFOC consists of humus, existing as stable carbon pool. This study was carried out about the characteristics organic carbon distributions in the sediment of Hulunhu lake, which is the shallow lake in arid areas within the Mongolian Plateau. The results indicated that the content of TOC ranged from 9.18 to 61.68 g·kg-1, with the average of 34.64 g·kg-1; the content of HFOC ranged from 9.02 to 61.47 g·kg-1, with the average of 34.32 g·kg-1; and the content of LFOC ranged from 0.02 to 0.86 g·kg-1, with the average of 0.32 g·kg-1. The content of TOC showed a decreasing trend from northwest to southeast in spatial distribution. The mean C/N ratio of the sediment was 20.35 in the surface sediments of Hulunhu lake, Which meant that the source of organic matter was diverse.