光照时间对外源性磷在模拟水生态系统中迁移的影响

采用同位素示踪法,模拟研究不同光照时间对外源性无机磷酸盐在水体,铜绿微囊蓝细菌和底泥中迁移的影响.外源性磷在加入水体后先是一种物理化学的快速分配,然后其在水体中的迁移主要受微囊蓝细菌的生长状况的影响.延长光照时间能加快微囊蓝细菌的生长速率和提高微囊蓝细菌的密度.水体中外源性磷的浓度随时间下降,蓝细菌中外源性磷的最大浓度与光照时间无关,只有蓝细菌中超积累了一定数量的外源性磷,随后的对数生长就与细胞磷的含量无关.延长光照时间能增加微囊蓝细菌中总的外源性磷数量,随着蓝细菌的衰亡,外源性磷不断向底泥迁移,最终绝大部分外源性磷都迁移到底泥中.

Effect of Light Period Length on the Movement of Exogenous Phosphorus within Simulative Aqueous Eco-systems

Effect of light period length on the movement of exogenous phosphorus within aqueous eco-systems composed with water, Microcystis aeruginosa and sediments was studied by the method of phosphorus isotope tracer. Exogenous phosphorus was initially distributed rapidly in the systems in a mode of physical chemistry and then its movement was significantly influenced by the growth of M. aeruginosa . With the increasing of the light period length, the growth rate and cell density rose gradually and exogenous phosphorus level declined rapidly in the water. The light period length had nothing to do with the maximum of endocellular phosphorus per mg M. aeruginosa. After certain amounts of exogenous phosphorus were accumulated in M. aeruginosa , its growth didn't affect the amounts of endocellular phosphorus. When the light period length was long, the total amounts of exogenous phosphorus was high in M.aeruginosa . The exogenous phosphorus moved from water and cyanobacteria to sediment continuously until most of exogenous phosphorus transferred into sediment through the decline of M. aeruginosa.