不同生物量伊乐藻微系统的水质变化分析

Changes of water quality in elodea nuttalli microecosystem with difference biomasses

在不同生物量水平的伊乐藻微系统中加入不同数量高浓度营养盐配制液后,观测分析主要水质指标变化规律以及植物生物量对水质指标变化的贡献。研究发现:(1)在中、高两种浓度水平下,NH_4^+-N、NO_3^--N、PO_4^(3-)-P、TN和TP的平均浓度均在无植物对照组、中生物量组、高生物量组依次减小;而植物净增长量在中生物量组、高生物量组、无植物组依次减小。(2) NH_4^+-N和NO_3^--N在有植物组显著小于无植物组,而不同生物量组间的差异相对较小; PO_4^(3-)-P则在高生物量组显著小于中生物量组和无植物组,而中生物量组和无植物组间差异相对较小。总体上,相对于植物总生物量,沉水植物净生长量对水体中主要营养盐浓度变化的影响相对较小;植物存在与否对N素指标影响相对较显著,而对于P素指标,生物量相对大小的影响更为显著。

The changes of main water quality indexes and the contribution of plant biomass to the change of water quality index were observed and analyzed after adding different quantities of high concentration nutrient solution in Elodea nuttallii micro-system with different biomass levels. The results showed that： （1） The average concentrations of NH4^＋-N, NO3^--N, PO4^3--p, TN and TP were decreased in the non-plant control group, medium biomass group and high biomass group in the middle and high concentrations, while the plant net growth was in medium biomass, high biomass group, and no plant group decreased successively. （2） NH4^＋-N and NO3^--N in the plant group were significantly smaller than the non-plant group, while the difference between the different biomass groups was relatively small; the PO4^3--P in the high biomass group was significantly smaller than the medium biomass group and the non-plant group, while the difference between the medium biomass group and the non-plant group was relatively small. On the whole, compared with the total plant biomass, the net growth of the submerged plant has a relatively small effect on the concentration of the main nutrient in the water body, and the effect of plant presence on N index is relatively significant, but for P index, the relative size of biomass is more significant.