铬污染对雷竹林土壤质量的影响

Effects of Cr Pollution on Soil Quality of Phyllostachys violascens ‘Prevernalis’ Forests

竹子具有较高的生物量和较强的重金属耐性,是一种极具潜力的植物修复材料。然而,目前尚不清楚铬(Cr)污染环境下,Cr对雷竹林土壤性质的影响。笔者研究了雷竹根际与非根际土壤理化性质沿Cr污染梯度分布的变化特征,分析了土壤理化性质与Cr含量之间的相互关系。结果表明:土壤pH值和碱解氮随Cr污染的增加而降低,有机碳随Cr污染的增加而增加;比较根际与非根际土壤,低Cr污染土壤的总Cr和有效Cr含量无显著差异,而中度和高污染的非根际土壤的有效态Cr含量均显著高于根际土壤;中度和高污染土壤有效Cr占总Cr的含量达到1.5%~2.6%,显著高于低污染土壤;土壤Cr含量与总有机碳和有效Cr呈正相关,与pH值呈负相关;在非根际和根际土壤中,随着Cr浓度的增加,土壤pH值和速效钾降低,有机碳和有效磷增加。笔者通过Cr污染对雷竹林土壤质量的影响研究,为提高竹子生态修复效果提供了科学依据。

Because of its high biomass and strong heavy metal tolerance, bamboo boasts huge phytoremediation potential. However, the effects of Cr pollution on the soil properties of Phyllostachys violascens ‘Prevernalis’ forests are still unclear. In this study, the physicochemical properties of rhizosphere and non-rhizosphere soils of Ph. violascens ‘Prevernalis’ along Cr pollution gradient were investigated, and the relationship between soil physicochemical properties and Cr content was analyzed. The results showed that soil pH and the content of alkali-hydrolyzable nitrogen decreased with the increase of Cr pollution, while the content of organic carbon increased with the increase of Cr pollution. There were no significant differences in the contents of total and available Cr between rhizosphere soil and non-rhizosphere soil with low Cr pollution, but the contents of available Cr in non-rhizosphere soil with moderate and high Cr pollution were significantly higher than those in rhizosphere soil. The available Cr in the soils with moderate and high Cr pollution accounted for 1.5%-2.6% of total Cr, which were significantly higher than that in the soil with low Cr pollution. Cr content in the soil was positively correlated with the contents of total organic carbon and available Cr, but was negatively correlated with soil pH. In both non-rhizosphere and rhizosphere soils, with the increase of Cr concentration, soil pH and the content of available potassium decreased, and the contents of organic carbon and available phosphorus increased. This paper unveils the impacts of Cr pollution on soil quality of Ph. violascens ‘Prevernalis’ forests, which provides scientific basis for improving the phytoremediation effect of bamboo.