| Bryophytes are widely used to enrich and monitor heavy metal pollutants in the environment all over the world due to their unique physiological characteristics.Hohhot is the capital of Inner Mongolia Autonomous Region.The environmental pollution caused by urban development has always been concerned.This study used ICP-OES to determine the heavy metal elements in bryophytes and soil samples in Hohhot,in order to evaluate local heavy metal pollution levels and select meaningful moss species as biological monitor.The main findings are as follows:(1)There are 6 families,9 genera and 17 species of dominant bryophytes were collected in Hohhot,among which above 50% are Bryaceae and Pottiaceae plants.(2)Correlation analysis between bryophyte population parameters and heavy metal content shows the content of heavy metals in Cd,Cr,Cu,Pb and Zn is negatively correlated with biomass and saturated water absorption,the contents ofheavy metal elements of Al,Fe,Mn and Ni are positively correlated with biomass and saturated water absorption.(3)Analysis of heavy metal elements in bryophytes shows Brachythecium rutabulum has a strong enrichment effect on Cd elements,and Funaria hygrometrica has a strong enrichment effect on Zn elements.Inter-species analysis of variance showed that different bryophytes had different absorption and enrichment effects on heavy metal elements.The contents of Al,Cd,Cr,Fe and Ni are extremely significant different in the Brachythecium buchananii,the Brachythecium rutabulum,the Brachythecium salebrosum and Didymodon Hedw.The content of As and Zn is significantly different in four bryophytes.After comprehensive consideration,it is recommended to use Bryum argenteum to enrich and monitor the environmental heavy metal pollution in Hohhot.(4)Comparing and analyzing the potential ecological hazard index of heavy metals in bryophytes and soil matrix in each functional area,it is found that the plants and soil samples have the same performance: the highest index is in the area of science and education area and urban-rural frige,followed by industrial areas and city parks.Roads,residence community and business zone have low indices.(5)The detection results of heavy metal contents in soil samples showed that the degree of heavy metal pollution in different functional areas is different,and the order is: Urban-rural fringe > Science and education area > Indusrial area > City Park > Business zone > Residence Community > Urban road,and the Cd element is the main ecological risk factor,and it is necessary to strengthen the treatment of Cdpollution.(6)The correlation between the content of elements in the bryophytes and the corresponding matrix soil is not significant,which indicates that the content of heavy metal elements in bryophytes is less affected by soil matrix,mainly from atmospheric sediments presumably.There is a significant correlation between various elements in bryophytes.There are extremely significant correlation between the following elements: Fe-Al,Mn-Al,Cu-Cr,Mn-Cr,Ni-Cr,Mn-Fe,Ni-Mn and Ni-Fe(P<0.01),there is a significant correlation between Cr-Al,Ni-Al,Mn-Cu and Ni-Pb elements(P<0.05).This indicates that the plants have synergistic absorption effect between different elements.This study shows that the environmental heavy metal pollution in Hohhot can be monitored by using Bryum argenteum.The city's science and education area and urban-rural fringe are seriously polluted,and Cd elements are the main pollutants.The treatment of this element needs to be stepped up. |
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