背角无齿蚌滤食对营养盐和浮游藻类结构影响的模拟

利用微型生态系统研究背角无齿蚌（Anodonta woodiana）高密度养殖情况下对微型生态系统水柱中不同形态氮磷浓度和浮游藻类群落结构的影响，结果显示蚌的高强度滤食：（1）减少微型生态系统中悬浮态氮的含量，明显增加厂水柱中的溶解性氮、磷含量，但是对总氮、总磷和正磷酸盐含量没有显著影响；（2）显著减少所有浮游藻类的数量和生物量，提高水体透明度，同时迅速改变微型生态系统中浮游藻类的群落结构，降低了微囊藻等蓝藻的数量及其所占的相对百分比，而绿藻所占的比例迅速上升；（3）导致微型生态系统的生态结构发生了显著变化，上行效应（Bottom-up effects）在浮游藻类与营养盐的关系方面发生了变化，实验组水柱中氮、磷含量与浮游藻类的相关关系显著降低；（4）并不能有效降低微型生态系统的富营养水平．

Top-down effects of Anodonta woodiana on nutrient concentration & phytoplankton community composition in a microcosm ecosystem

Microcosm experiments were conducted to study the impacts of intensive cultivation of Anodonta woodiana on nutrient concentration(different forms of phosphorus and nitrogen)and phytoplankton community structure.The results showed that the bivalve increased the concentration of total soluble phosphorus,total soluble nitrogen,and water transparency,but had decreased the concentration of particle nitrogen.There were,however,no significant influences on the total phosphorus,total nitrogen,and ortho-phosphorus.T...