磷的不同动态变化对模拟湖泊生态系统中附草螺类的影响

采用试验围隔模拟湖泊富营养化过程,选取磷的不同动态变化,研究其动态输入模式对附草螺类的影响。结果表明,总量相同时,中短期内低频次的磷输入比高频次的磷输入对螺类生物量的影响更显著,而长期条件下高低频次的磷输入对螺类生物量的影响无显著差异(P>0.05)。营养的添加显著促进螺类生物量(密度和丰度)的增长。试验系统中附植藻类的生物量与螺类的生物量成显著负相关(P<0.05),沉水植物刺苦草(Vallisneria spinulosa)与螺类(Radix)生物量的相关性不显著(P>0.05),表明螺类是螺类-附着藻-沉水植物系统的关键调控因子,而沉水植物可能会因生态系统状态的差异而存在不同的响应机制。

The effects of phosphorus dynamics on snails of epiphytic gastropods in mesocosm lake ecosystem

Different phosphorus dynamics have significant impacts on the biomass of snails in the first month during the experiment. With the same total loading amount, the biomass of snails in the low-frequency patterns increases faster than that in the high-frequency patterns. But the significance decreases with the increased experiment time. Nutrient addition has increased snails by a large amount. Correlation analysis show that the biomass of the epiphyte has negative correlation with the biomass of snails, but the correlation is insignificant between the biomass of the macrophyte and the biomass of snails, which indicates snails are the important factor in the complex snail-epiphyte-macrophyte system and the interaction between the macrophyte and snails changes in the different lake ecosystems.