黑藻群丛对水体氮素和其他主要环境因子日变化的影响

Effects of Diurnal Variation of Hydrilla verticillata Photosynthesis on Nitrogen and Some Other Major Environmental Factors in Water

通过引种黑藻(Hydrilla verticillata)构建了沉水植物-水-沉积物模拟微实验系统,研究了沉水植物黑藻生理活动的日变化对水体氮素迁移转化及其他环境因子的影响。结果表明,黑藻组水体中溶解氧浓度、pH值和氧化还原电位显著高于对照组(无黑藻水体)(P<0.05),溶解性总固体浓度显著低于对照组(P<0.05);溶解氧浓度、pH值和氧化还原电位日变化均呈单峰曲线,15:00时达到峰值。水体NH4+-N和TN浓度始终保持稳定,且低于对照组。从日变化规律来看,在15:00—18:00之间NO3--N平均浓度较高,在24:00—次日2:00 NO2--N浓度较低。

A simulated submerged plant-water-sediment micro-ecosystem was established in an experiment using an alien species of submerged plant,Hydrilla verticillata to study the effects of the diurnal changes in physiological activities of H.verticillata on migration and transformation of nitrogen and some other environmental factors in water.Results show that the presence of H.verticillata significantly increased DO concentration,pH,and Eh,but lowered TDS.The diurnal variations of water pH,DO and Eh all displayed a single-peak curve.The peaks appeared all around 15：00.In addition,the concentrations of total nitrogen （TN） and NH4＋-N remained nearly constant but relatively lower than that of the control during the whole day.The mean concentration of NO3--N was relatively higher between 15：00 to 18：00,and the mean concentration of NO2--N relatively lower between 24：00-2：00 next day as compared to the control.