附着生物对沉水植物伊乐藻生长的研究

Effect of periphyton on the growth of Elodea nuttalii

以沉水植物伊乐藻（Elodea nuttalii（Plant.）ST.John.）为研究对象,室内利用原位湖水进行培养,通过测定伊乐藻的生物量、叶绿素质量分数、光合作用速率等指标,研究了附着生物量的增加对沉水植物伊乐藻的影响。结果表明,随着附着生物处理量的增加,伊乐藻的生物量、叶绿素质量分数以及光合作用速率随之下降,50d后,各处理的生物量与对照相比分别减少了约5%-15%,叶绿素质量分数以及光合作用速率下降了20%-43%、10%-36%。同时也分析了丝状藻对沉水植物伊乐藻的遮阴作用,初步推测附着生物对沉水植物伊乐藻的影响可能是由于附着生物的遮荫作用。研究的结果为揭示富营养化湖泊沉水植被衰退的机理提供了理论依据。

The indoor cultivation experiment was conducted, to investigate the effects of increased periphyton biomass on growth of Elodea nuttallii. The biomass, chlorophyll content and photosynthesis rates about E. nuttallii growing in lake water were measured. Results indicated that all three indices of biomass, chlorophyll content and photosynthesis rates about E. nuttallii decreased with the increase of periphyton biomass. In comparison with the control, the treatments with increased periphyton biomass resulted in 5%-15%decrease of biomass of E. nuttallii, 20%-43%decrease of chlorophyll contents, and 10%-36% decrease of photosynthesis rates. A further investigation suggested that the shading effect of periphyton might influence the photosynthesis and therefore the biomass of E. nuttallii. Our investigations would probably provide an opportunity to further understand the recession mechanism of submerged vegetation in Eutrophication Lake.