鱼池生态系统中影响浮游细菌生长制约因素的研究

Main factors influencing the growth of planktonic bacteria in fish pond ecosystem.

从溶解有机质及营养盐对细菌生长、细菌利用和矿化营养物质的影响 ,细菌捕食者和水温对细菌生长的影响等方面就鱼池生态系内影响细菌生长的主要制约因素进行研究 .结果表明 ,向池水中添加P明显促进了细菌的生长和对C、N素的吸收 ,而添加C和N对细菌数量增长和营养物质吸收的作用不明显 ,但添加N明显增强了细菌对有机N的矿化能力 ,表明原池水中C、N供应充足 ,而无机磷限制了细菌的生长和对营养物质的利用 ;捕食组的细菌生长速率最低 ,比对照组减少 6 .2 6 %～ 15 .4%,且增长结束后细菌数量下降较其它组显著 ;池塘水体的原有细菌丰度、试验培养中细菌增长数量和生长速率在温度较高的季节也较高 ,温度升高促进了细菌生长 ,减弱捕食对细菌生长的负作用 .

Focused on the main factors influencing the growth of bacteria in fish pond ecosystem, the variation of abundance in bacterial culture, the effects of substrate on bacterial growth, nutrient uptake and mineralization, the effects of bacterivorous predator and water temperature on bacterial growth were investigated in this paper. The results showed that the growth of bacteria and its uptake of C and N were enhanced by application of inorganic phosphorus into the water, but not by application of organic carbon and nitrogen, and that the N mineralization was increased by adding organic nitrogen, indicating that the bacterial growth was limited by inorganic P in the substrate, not by organic C and N. Among the five test groups,predator bacteria had the slowest growth rate,being lower than the control by 6 26～15 4%. The abundance of bacteria,its number increment and growth rate in the fish pond were found to be positively correlated with water temperature in different seasons.In addition,at higher temperature,the positive effects of nutrient application on bacterial growth were enhanced,while the negative effects of predator bacteria on bacterial growth were weakened.