Nualgi营养素、硅藻藻种对池塘水质和浮游植物的短期效应研究

为探讨短期内Nualgi营养素对池塘水质和藻类群落结构的影响,本研究在池塘中的不透水有底帆布围隔内共设计了4个试验组,依次分别添加Nualgi营养素(M1组)、补充硅藻藻种(M2组)、同时添加Nualgi营养素并补充硅藻藻种(M3组)、不做任何处理的空白对照(C组)。经过近一个月的试验,结果显示:各组的pH值、DO、TN、TP之间没有显著性差异;Nualgi可以显著降低水体中IP的含量,M1组和M3组的IP显著低于M2组和C组;M1组、M2组和M3组中的NH_4~+-N、NO_2~--N和CODMn含量显著低于C组,表明Nualgi和硅藻藻种都可以显著降低水体中NH_4~+-N、NO_2~--N和CODMn的含量,对养殖水质具有显著的调控效果。试验各组的藻类种群极为丰富,试验期间共检出浮游植物7门109属186种,其中绿藻门47属86种,硅藻门26属48种,蓝藻门18属27种,裸藻门11属17种,甲藻门3属3种,隐藻门2属3种,金藻门2属2种。结果显示:添加Nualgi和补充硅藻藻种都可以有效提高水体中硅藻的生物量并抑制绿藻和蓝藻的生长,同时可以改变水体中浮游植物的群落结构,试验进行到第20天时,M1组、M2组和M3组中硅藻的生物量均显著高于C组,绿藻和蓝藻的生物量显著低于C组。试验中,颗粒直链藻在M1组、M2组和M3组中成为优势藻种,但并未在C组中成为优势藻种,小空星藻和四足十字藻仅在C组中成为优势藻种,四尾栅藻在M1组、M2组和C组中均成为优势藻种。在试验期内,各试验组之间的多样性指数没有显著差异,香农-威纳指数均在2.00以上,表明Nualgi和硅藻藻种并没有影响到水体中藻类的多样性。

The short-term effects of biological nutrient Nualgi and diatom algaes on the water quality and phytoplankton in culture pond

In order to study the short-term effects of biological nutrient Nualgi on water quality and phytoplankton in fish-pond, we conducted continuous and regular surveys for three weeks on the phytoplankton community and the water quality indexes in 4 groups. The 4 groups were a Nualgi group(M1), an algae group(M2), a Nualgi and algae group(M3) and a control group( C) . The results showed that the pH, DO, TN, TP had no remarkable difference among the 4 groups. IP in group M1 and M3 were remarkably lower than group M2 and group C, meaning Nualgi can reduce IP in water. Levels of NH4 +-N, NO2 --N and CODMn in group M1, M2 and M3 were remarkably lower than that of group C, meaning Nualgi or algae can both reduce NH4 +-N, NO2 --N and CODMn to adjust water quality. During the test, we identified 186 species that belonged to 7 phyla and 109 genera. 86 species were Chlorophyta, 48 were Bacillariophyta, 27 were Cyanophyta, 17 were Euglenophyta, 3 were Dinophyta, 3 were Cryptophyta and 2 were Chrysophyta. Adding diatom algae or Nualgi can both promote the growth of Bacillariophyta and restrain the growth of Chlorophyta and Cyanophyta. In the test, Melosira granulata became the dominant algae in group M1, M2 and M3 but without group Coelastrum microporum and Crucigenia tetrapedia are the dominant algae in group C only. Scenedesmus quadricauda became the dominant algae in group M1, M2 and C. There were no remarkable difference between the 4 groups about the diversity index, and the Shannon-Wiener in-dex were all above 2. 00, which showed that the species diversity is abundant.