太阳辐射减弱对浮游与底栖藻类竞争的影响

为了解辐射减弱对浮游藻类和底栖藻类竞争的影响，构建了浅水生态系统，设置遮光组和不遮光的对照组两种处理，通过测定水中氮、磷营养盐、浮游藻类生物量及底栖藻类生物量等指标，分析遮光时浮游藻类和底栖藻类生长变化，研究辐射减弱对浮游与底栖藻类竞争的影响。结果表明，遮光条件下，水体浮游藻类Chl a降低15%，DO浓度平均增加9%，TN、TP浓度分别增加30%和24%时，底栖藻类Chl a增加48%。说明辐射减弱虽可显著降低水体光照强度和浮游藻类生物量，但可提高水体中氮、磷营养盐浓度，促进底栖藻类生物量增加。因此，在辐射减弱背景下，不利于浮游藻类生长，而有利于底栖藻类竞争。

Effects of solar radiation reduction on planktonic-benthic algae competition

In order to evaluate the effect of solar radiation reduction on the competition between planktonic algae and benthic algae, a shallow mesocosms was constructed. The shading treatment group and the control without shading were designed. The effects of solar radiation reduction on the competition between plankton and benthic algae were studied by measuring nitrogen and phosphorus, planktonic algal biomass and benthic algal biomass in the mesocosms. The results showed that under the shading conditions, the planktonic algae chlorophylla in the water column decreased by 15%, DO concentration increased by 9% on average, and benthic algae chlorophylla increased by 48% when TN and TP concentrations increased by 30% and 24%, respectively. It indicates that radiation weakening can significantly reduce the light intensity and planktonic algal biomass, but it increased the concentration of nitrogen and phosphorus nutrients, and benthic algal biomass. So, it would be favorable to the competition of benthic algae and unfavorable to the growth of pelagic algae under the background of solar radiation reduction.