基质类型对两种沉水植物种间关系的影响

Effects of sediment nutrition level on the interspecific relationship between two submerged macrophytes

以外来种伊乐藻与土著种苦草为实验生物,通过室外受控实验研究了基质类型对2种水生植物种间关系的影响。结果表明:伊乐藻在2种不同营养水平的基质中均具有明显竞争优势。植物竞争(混栽伊乐藻)对低密度苦草的生长影响不明显,对密度高苦草抑制显著,然而基质类型对低密度苦草的生长影响显著,对高密度苦草无明显影响。同样,植物竞争(混栽苦草)对低密度伊乐藻的生长无明显影响,对密度高伊乐藻抑制显著,然而,无论种植密度高低,基质类型对伊乐藻的生长均有极大影响。本文还对伊乐藻与苦草的种间竞争关系机理进行了探讨,其研究结果对分析外来种入侵后水生植被的演变规律以及湖泊水生植被的管理有一定参考价值。

A 2 × 2 factorial field experiment was conducted to study the effects of sediment nutrition level on the interspecific relationship between two submerged macrophytes,exotic Elodea nuttallii and native Vallisneria spiralis.On the sediments with either high or low nutrition level,E.nuttallii had an obvious superiority in competition.Under the mixed planting with E.nuttallii,the growth of low density V.spiralis was less affected,but that of high density V.spiralis was inhibited significantly.The same picture was observed in the E.nuttallii growth under the mixed planting with V.spiralis.Sediment nutrition level affected the growth of E.nuttallii at both low and high densities significantly,but only had significant effects on the growth of low density V.spiralis.It was suggested that exotic submerged macrophyte E.nuttallii would affect the species distribution and structure of aquatic plant communities in lake ecosystems.