[Ecological characteristics of Zostera japonica population in Swan Lake of Rongcheng, Shandong Province of China].

In this study, a large area of well preserved Zostera japonica dominated meadow was found in a coastal lagoon, Swan Lake, in Rongcheng of Shandong Province. Due to its unique geographical position and high biomass, this meadow may act as a typical Z. japonica bed in the coastal area of Shandong. From September, 2011 to October, 2012, an annual investigation was conducted on the Z. japonica and its habitats in east coast of Swan Lake, and the distribution of the Z. japonica and its habitats ecological characteristics were preliminarily understood. The major ingredients of sediments particles in the Z. japonica bed was sand (81%) and silt (14%). The C and N contents in the sediments were the highest in winter, and the C/N ratio was the highest in autumn. The shoot density, shoot height, and biomass of the Z. japonica were all significantly correlated with water temperature (P < 0.05). There was an obvious change in the Z. japonica growth among seasons, with the peak biomass obtained in August-September. The C and N contents and C/N in Z. japonica leaves also varied with seasons. The leaf C content was significantly higher in autumn than in spring and summer (P < 0.05), the leaf N content was significantly lower in summer than in spring and autumn (P < 0.01), whereas the leaf C/N ratio was significantly higher in summer than in spring (P < 0.05). The annual carbon sequestration by the Z. japonica in the Swan Lake was estimated to be 111.4 g C x m(-2).