不同造林树种对铁尾矿基质结构的影响——以唐山迁安首钢马兰庄铁尾矿为例

Effects of Different Vegetation Restoration Types on Soil Structure in Iron Tailings——A case Study of Malanzhuang Iron Tailings

为了探讨不同树种对铁尾矿土壤结构的改良作用,以唐山迁安马兰庄铁尾矿区为研究地,选择在尾矿坡面造林的沙地柏、紫穗槐油松混交(简称"混交")、紫穗槐、火炬树、沙棘为研究对象,测定其林内土壤机械组成、团聚体含量、土壤容重、土壤孔隙度及土壤水分,并与裸尾矿进行对比分析。结果表明:1)6块样地石砾的含量为火炬树(23.1%)>混交(10.4%)>裸尾矿(9.2%)>沙地柏(5.4%)>紫穗槐(4.0%)>沙棘(2.2%);2)6块样地大团聚体含量由高到低依次为沙棘(33.7%)>紫穗槐(29.3%)>沙地柏(28.7%)>裸尾矿(18.3%)>混交(13.6%)>火炬树(11.7%),与石砾含量的顺序相反;3)除火炬树样地与裸尾矿相同外,其余各样地土壤容重均有降低,其中紫穗槐的改良效果最为突出,比裸尾矿地减小12.1%;4)除沙棘样地非毛管孔隙度比裸尾矿样地降低以外,其余各样地的土壤总孔隙度、毛管孔隙度、非毛管孔隙度均增加,增加效果最好的两个样地为沙地柏样地和紫穗槐样地;5)沙地柏对田间持水量、毛管持水量和饱和含水量的改善作用明显,其次为火炬树样地,混交林改善作用不显著。综上所述,采用沙地柏或油松与紫穗槐混交的模式能较好地对土壤各个层深的物理性质和有机质进行综合改良。

In order to investigate the role of different vegetation restoration patterns on soil structure in iron tailings,Tangshan Qianhn Malanzhuang Iron tailings were taken as research. This paper selected 5 typical slope woodland railings ,they are Sabina vulgaris ,Amorpha fruticosa and Pinus tabuliformis mixed ,Amorpha fruticosa,Rhus typhina,Hippophae rhamnoides as the research object,measured in its soil mechanical com- position, aggregate content, soil bulk density, soil porosity, soil moisture, and analyzed with bare railings. The results were as follows：l ）Gravel content of 6 plots from high to low was ：R. typhina forest（23. 1% ） 〉 mixed forest （ 10. 4% ） 〉 bare tailings （ 9. 2% ） 〉 S. vulgaris forest （ 5. 4% ） 〉 A.fmticosa forest （ 4. 0% ） 〉 H. rhamnoides forest（2. 2% ） ;2） Large aggregate content of 6 plots from high to low was：H, rhamnoides for- est（33.7% ） 〉A.fruticosa forest （29. 3% ） 〉 S. vulgaris forest （28.7%） 〉 bare railings （ 18. 3% ） 〉 mixed forest（ 13.6% ） 〉R. typhina forest（ 11.7% ）. Sequence coincides with the reverse sequence of gravel con- tent. 3 ） The bulk of the R. typhina forest was equal to the bare tailings, and others were lower than bare tail- ings after revegetation. The effect of A.fruticosa forest to bulk seemed to be most prominent,which reduced 12. 1%. 4）Except non capillary porosity of 1-1. rhamnoides forest lower than bare tailings, total porosity of soil, capillary porosity and non capillary porosity of the rest fields had all increased visibly. The top two plots is S. vulgaris forest and A.fruticosa forest. 5 ）The most obvious improvement effect to field capacity and capillary moisture capacity was S. vulgaris, followed by R. typhina, mixed forest improvement was not signifi- cant. In summary, S. Vulgaris and mixed forest types had better comprehensive improvement of physical properties of different deep layer of soil and organic matter.