山东荣成天鹅湖矮大叶藻种群的生态特征

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

在山东荣成天鹅湖发现较大面积的矮大叶藻,因天鹅湖独特的地理位置和矮大叶藻的高生物量,可以作为山东沿海矮大叶藻的典型代表.2011年9月至2012年10月,对天鹅湖东岸矮大叶藻及其生境进行了周年调查,初步掌握了该种的分布情况及其生境的生态特征.结果表明:矮大叶藻床沉积物成分以砂(81%)和粉砂(14%)为主,沉积物C、N含量在冬季最高,C/N秋季最高;矮大叶藻的密度、高度和地上生物量与水温显著相关(P<0.05),生长呈现明显的季节变化,8—9月生物量最大.叶片的C、N含量及C/N因生长季节的不同而存在一定差异,C含量秋季显著高于春、夏季,N含量夏季显著低于春、秋季(P<0.01),C/N夏季显著高于春季(P<0.05).经估算,天鹅湖矮大叶藻的年固碳能力为111.4 g C.m-2.

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 lll.4gC·m-2.