滩涂池塘生态系统的光合能量利用及其影响因子

研究了江苏沿海滩涂不同养殖模式下初级生产力特征、能量利用率及其影响因子.结果表明,滩涂养殖水体浮游植物的初级生产力存在垂直分布、日变化和季节的动态变化,这种变化与太阳辐射强度有直接的关系.滩涂养殖水体净初级生产量平均值为(7.58±2.52) gO2/(m2 · d),只占毛产量的55.41%,太阳能转化为鲢、鳙鱼产量的生态效率为0.020%～0.029%,这些指标低于我国高产养殖塘,鱼塘生态系统结构有待进一步优化.浮游植物生物量、透明度、N/P值、Mg2+浓度等因素显著影响水体初级生产力的大小,多元逐步回归表明浮游植物叶绿素含量和到达水体表面的太阳辐射强度是初级生产力的最主要因子,其回归方程为:Pg =0.0785Cha+0.0577 Iλ0+1.346;n=22, FCha>F Iλ0>F0.1,而盐度、Na+、Cl-浓度影响不显著.

Impact factors of photosynthesis energy utilization in the coastal fish ponds of Jiangsu Province

The characteristics of primary productivity, utilization of solar energy efficiency and their impact factors under the different culture models were studied in the coastal fish ponds of Jiangsu. The results showed that there existed dynamic changes of the primary productivity (such as vertical distribution, daily variation and seasonal changes) in the water of fish ponds, and thus changes were directly related to the solar radiation intensity. The average net primary productivity (Pn) was (7.58±2.52) gO2/(m2·d), which was only about 55.41% of gross primary productivity (Pg). The ecological efficiency of transforming solar radiation energy to carp products was from 0.020% to 0.029%, the ecological indexes were lower in the coast fish ponds than the high-yield ponds, indicating that the ecosystem structure needs to be further optimized. The primary productivity of the water was significantly affected by the phytoplankton chlorophyll, solar radiation intensity, phytoplankton biomass, transparency, N/P ratio, Mg2+ concentration, but not significantly influenced by the contents of total salts and concentrations of Na+ and Cl- in the water.