单种及混合种植对花叶芦竹铅积累量的影响

该研究采用盆栽试验法,选取石菖蒲、水生鸢尾、美人蕉、花叶芦竹为试验材料,将石菖蒲、水生鸢尾、美人蕉与花叶芦竹混种,用花叶芦竹单种作为对照,研究了混种对花叶芦竹生物量、根冠比以及铅积累量的影响。结果表明:(1)在不同浓度铅污染处理下,与花叶芦竹单种相比,混种模式增加了花叶芦竹的根冠比,且随着铅污染浓度的增加,表现出先上升后下降的趋势。(2)在单种和混种模式下花叶芦竹体内和土壤内的铅含量均表现出明显的浓度积聚效应;在混种模式下植物体内和土壤内的铅含量明显低于单种模式,且与单种模式之间的差异性显著(P0.05)。(3)在高浓度铅污染处理下,单种和混种模式的花叶芦竹铅转运系数均大于1,而富集系数则表现为在低浓度和高浓度铅污染处理下均大于1;在美人蕉+花叶芦竹的混种模式中,花叶芦竹的地上部分和地下部分的铅富集系数达到最大。因此,我们认为美人蕉+花叶芦竹混种模式,显著提高了花叶芦竹的生物量和根冠比,并对铅污染土壤的净化效果最佳。

Effects of independent planting and mixed planting of Arundo donax on lead accumulation

We studied the effects of mixed planting pattern on the biomass, root-shoot ratio and lead accumulation of Arundo donax, through potting experiment in outdoor, by selecting Acorus tatarinowii, Iris tectorum, Canna indica and Arundo donax as experimental materials. The mixed patterns were formed by Acorus tatarinowii + Arundo donax, Iris tectorum + Arundo donax, Canna indica + Arundo donax, and Arundo donax was taken as control. The results were as follows:(1)Compared with the single pattern, mixed planting patterns with three aquatic plants improved the root-shoot ratio of A. donax under the different concentrations of lead pollution. With the increase of lead pollution concentration, the root-shoot ratio showed an upward and then downward trend.(2)The lead content in the body and the soil of A. donax showed obvious concentration accumulation effect in the single and mixed planting patterns. The lead content in plants and soil in mixed plan-ting patterns was significantly lower than that in the single planting pattern, and the differences were significant between single and mixed planting patterns(P<0.05).(3)Under the treatment of high concentration lead pollution, the translocation factor of A. donax was greater than 1 in the single and mixed planting patterns. However, the bioconcentration factor was greater than 1 in the low and high concentrations of lead pollution treatments. In the Canna indica + Arundo donax pattern, the lead bioconcentration factor of Arundo donax was the largest in both above-ground and below-ground parts. Therefore, we believed that Canna indica + Arundo donax pattern significantly increased the biomass and root-shoot ratio of Arundo donax, and had the best purification ability to lead contaminated soil.