背角无齿蚌(Anodonta woodiana)对浅水系统底栖和浮游藻类竞争关系的影响

The effect of Anodonta woodiana on the competitive relationship between benthic and planktonic algae in shallow aquatic ecosystem

底栖藻类和浮游藻类之间的竞争关系对浅水生态系统的结构、功能具有重要的影响,双壳类可通过滤食控制浮游藻类,从而改变底栖藻类与浮游藻类之间的竞争结果。论文通过比较放养背角无齿蚌(Anodonta woodiana)(蚌处理组)与不放养背角无齿蚌(对照组)系统中底栖藻类、浮游藻类的生物量和优势种等的变化,研究了滤食性双壳类对底栖藻类和浮游藻类间竞争的影响。结果表明,背角无齿蚌可显著降低浮游藻类生物量,提高水体透明度和沉积物表面光照条件,从而显著提高底栖藻类的生物量;背角无齿蚌也改变了浮游藻类的优势种,使优势种由蓝藻转变成硅藻。因此,滤食性双壳类有利于促进浅水生态系统从混水态向清水态转变,本研究结果对富营养化浅水湖泊修复与管理具有一定的参考意义。

The competitive relationship between benthic and planktonic algae plays an important role in the structure and fimction of shallow aquatic ecosystem. Bivalves can affect the planktonic algae biomass and community structure through filter-feeding, thus influencing the results of the competition between benthic and planktonic algae. In order to investigate the effect of filter-feeding bivalves on the competitive relationship between benthic and planktonic algae, we conducted an experiment with two treatments, one with Anodonta woodiana as bivalve treatments and one without A. woodiana as controls. The results showed that A. woodiana significantly reduced the biomass of planktonic algae and increased the biomass of benthic algae. The dominant species of planktonic algae changed from cyanobacteria to diatom in the bivalve treatments. Moreover, the transparency and light intensity over sediment surface in the bivalve treatments were higher than those of controls. Our study demonstrates that bivalves can change the competitive relationship between benthic and planktonic algae and thus may enhance the shift of shallow lakes from a turbid to a clear water state. This research has some implications for restoration and management of eutrophic shallow lakes.