河岸防护林对土壤重金属含量的影响及其生态风险研究

发布时间：2018-06-26 03:23

本文选题：重金属 + 土壤　；参考：《西南农业学报》2017年02期

【摘要】：为了解不同植被配置模式的河岸防护林土壤重金属的含量特征和污染状况,提出能有效降解土壤重金属危害的植被配置模式。本文选择了成都市沙河生态景观防护林带中的乔灌草、乔草、灌草以及单层灌木林和草坪等5种典型植被配置模式林分,测定了Mn、Cr、Co、Ni、Cu、Zn、Cd和As等重金属和全N、全K和全P等主要营养元素在土壤中的分配状况;并对土壤重金属的生态风险进行了评价。1 Mn、Zn、Cr和Pb等8种重金属元素含量在不同植被配置模式下均有显著性差异(P0.05),总体表现为Mn含量最高,Zn次之,再次是CrPbNiCuCo;As含量最低。2根据土壤环境质量标准(GB15618—1995)评价结果表明,Cr、Ni、Cu、Co和As在5中植被配置模式下均没有超过临界值,Zn在5种植被配置模式下的土壤含量均超过临界值;Mn和Pb则表现为部分配置模式下超过临界值;3土层中分配上,各元素总体表现为土层20~40 cm含量高于0~20 cm。4通过相关性对重金属的来源初步解析表明,0~20 cm土层中重金属来源明显比20~40 cm土层复杂。5Mn、Cr、Co等8种重金属元素在5种植被配置模式下主要表现为未污染或轻度污染和轻度危害。乔灌草配置模式I(植被从上到下依次为:香樟、女贞+十大功劳、迎春+鸢尾)重金属含量最低,综合污染指数和污染的生态风险指数最低。
[Abstract]:In order to understand the characteristics of heavy metals content and pollution in riparian shelterbelts with different vegetation allocation patterns, a vegetation allocation model which can effectively degrade heavy metals in soil was proposed. In this paper, five typical vegetation allocation models, such as Arbor and Irrigation, Arbor Grass, Irrigation, single layer shrub and Lawn, are selected in the shelterbelt of Shahe Ecological Landscape in Chengdu. The distribution of heavy metals, total N, total K and total P in soils, such as heavy metals, total N, total K and total P, were determined. The ecological risk of heavy metals in soil was evaluated. The contents of 8 heavy metals, such as mn, Zn, Cr and Pb, were significantly different under different vegetation patterns (P0.05). Again, CrPbNiCuCoAs content is the lowest .2 according to the soil environmental quality standard (GB15618-1995), the results show that both CrPbNiCuCoAs Co and as do not exceed the critical value under 5 vegetation allocation modes. The distribution of mn and Pb in the soil layer above the critical value of mn and Pb is higher than the critical value in the partial collocation mode. The results showed that the content of heavy metals in 2040 cm soil layer was higher than that in 0 ~ 20 cm.4 soil layer. The preliminary analysis of the source of heavy metals showed that the heavy metal source in the soil layer of 20 ~ 20 cm soil layer was obviously more complicated than that in 20 ~ 40 cm soil layer. 5MnCU Cr ~ (2 +) Co and other eight heavy metal elements were mixed in 5 planting plants. The main performance of the model is no pollution or mild pollution and slight harm. The distribution model I of Arbor and Irrigation grasses (from top to bottom): camphor camphora, Ligustrum privet, Iris japonicus) had the lowest heavy metal content, the comprehensive pollution index and the ecological risk index of pollution were the lowest.
【作者单位】：四川省林业科学研究院;
【基金】：林业公益行业专项课题“美丽城镇森林景观的构建技术研究与示范”(201404301)
【分类号】：X53;X173

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