4.2. Effects of the exudates of aquatic macrophytes and the pollutants on algal interactions
In the present study, the aquatic macrophytes completely inhibited the growth of M. aeruginosa and C. pyrenoidosa through allelopathic chemicals. It is similar to Mulderij et al. (2009) results that the aquatic macrophyte Stratiotes aloides suppress noxious phytoplankton growth partly through allelopathic effect. Furthermore, macrophytes may absorb surplus nitrogen and phosphorus, decompose Pb and PCBs, and inhibit algal growth by releasing allelochemicals. Thus it would destroy positive algal interaction or aggravate negative inter-specific relationship caused by the polluted conditions. In the treatments with higher aquatic macrophyte diversity the regulation effect on algal interaction became more powerful. The overall effects of the functional allelochemicals produced by these aquatic macrophytes on the ecosystem and the environment
require further investigation.