Abstract
In many of the world's lakes, the diversity of aquatic plants has collapsed. Dominance by lotus (Nelumbo nucifera) is generally considered to progress organicization of bottom sediment. However, the quantity of lotus-derived refractory organic matter remains unknown. In order to investigate the influence of lotus-derived refractory organic matter on lake sediment characteristics, lotus degradation experiments and field observations of Lake Izunuma were carried out.
The lotus degradation experiment lasted for 733 d, and the Multi-G model estimated that the residual ratio of particulate organic matter was about 35 and 58 % under aerobic and anaerobic conditions, respectively. In addition, by analyzing long-term lotus degradation and vertical sediment distribution, the present study suggests the possibility of estimating the refractory organic matter has been suggested by using an index of LCFAs/total fatty acid ratio.
