基于环境模拟的尾矿边坡水土保持植物筛选研究

Research on plant selection for water and soil conservation of tailings slope based on environmental simulation

为筛选尾矿边坡水土保持优良物种,选取江西5种乡土植物(芒萁、狗牙根、马唐、百喜草、三裂叶薯)作为研究对象,对其在模拟边坡种植后土壤水分物理性质及地表径流和土壤侵蚀情况开展研究,并采用熵权TOPSIS法对5种植物进行水土保持功能评价。结果表明:(1)芒萁、狗牙根、马唐、百喜草、三裂叶薯种植后边坡的土壤水分物理性质得到显著改善,土壤容重范围为1.26~1.40 g·cm^(-3),土壤总孔隙度在41.26%~48.11%之间,土壤含水量在8.2%~27.6%之间,土壤水分物理性质改善顺序为芒萁>狗牙根>马唐>百喜草>三裂叶薯;(2)芒萁、狗牙根、马唐、百喜草、三裂叶薯种植后相对于裸地,径流输出量和土壤侵蚀量显著减少,平均减少了46.43%和66.89%,大小顺序皆为芒萁>狗牙根>三裂叶薯>马唐>百喜草;(3)采用TOPSIS法对5种乡土植物水土保持功能的评价结果从大到小依次为芒萁>狗牙根>马唐>三裂叶薯>百喜草。综上,芒萁、狗牙根保持水土功能较强,在进行尾矿生态修复时可优先搭配芒萁、狗牙根,实现尾矿边坡水土流失防治和土壤改良模式优化。

To select excellent species for tailings slope water and soil conservation,five local plants(Dicranopteris pedata,Cynodon dactylon,Digitaria sanguinalis,Paspalum notatum and Ipomoea triloba)from Jiangxi Province were chosen as research subjects.A study was conducted on their soil moisture physical properties,surface runoff,and soil erosion after simulated slope planting.The entropy weight TOPSIS method was used to evaluate the water and soil conservation functions of the five plant species.The results showed that:(1)After planting D.pedata,C.dactylon,D.sanguinalis,P.notatum and I.triloba,the soil moisture physical properties significantly improved.The soil bulk density ranged from 1.26 to 1.40 g·cm^(-3),the total soil porosity was between 41.26%and 48.11%,and the soil moisture content ranged from 8.2%to 27.6%.The improvement order of soil moisture physical properties was D.pedata>C.dactylon>D.sanguinalis>P.notatum>I.triloba.(2)Compared to bare land,the surface runoff and soil erosion output significantly decreased after planting D.pedata,C.dactylon,D.sanguinalis,P.notatum and I.triloba.On average,they reduced by 46.43%and 66.89%respectively.The order of reduction was D.pedata>C.dactylon>I.triloba>D.sanguinalis>P.notatum.(3)Using the TOPSIS method to evaluate the water and soilr conservation functions of the five local plants,the order was D.pedata>C.dactylon>D.sanguinalis>I.triloba>P.notatum.In conclusion,D.pedata and C.dactylon have better water and soil conservation functions.When conducting tailings ecological restoration,it is recommended to prioritize the combination of D.pedata and C.dactylon to achieve the prevention and control of soil erosion and soil improvement on tailings slopes.