赫章土法炼锌区苔藓植物及其对环境中镉污染的监测评价(英文)

【摘要】：正Artisanal zinc smelting has posed serious environmental pollution in Hezhang County in southwestern China,and which was considered as one of the major sources of cadmium pollution in the environment. Bryophytes were investigated in the major areas of artisanal zinc smelting of Hezhang County.For the first time, the bryophytes consisting of 57 species which belong to 9 families and 27 genera were documented.The predominant families(5 genera) are Bryaceae and Pottiaceae,and the predominant genera(3 species) are Barbula, Bryum,Pohlia,Brachythecium,Ditrichum and Funaria.There are three types of life-forms of bryophytes present, namely short turfs,wefts and mats.The predominant type is short turf.Nine types of geographical elements (Cosmopolitan,Endemic to China,North Temperate,Tropical Asia,Tropical Asia and Tropical Africa,Tropical Asia and Tropical Oceania,Pan-tropical,Middle Asia,Eastern Asia) of moss distributions occur in this area. Among which North Temperate element,Cosmopolitan element,Endemic to China element,Tropical Asia element are dominant.Furthermore,using ecological and geochemistry method,we have estimated the average Cadmium concentration in bryophytes and their substrates.The bryophyte species,Trichodon muricatus Herz., Ditrichum brevidens Nog.,Barbula rufidula C.Mull.,growing on the surface of soils were analyzed.Cadmium concentration in the above three bryophyte species are 10.6 mg/kg,9.1 mg/kg and 8.6 mg/kg,and cadmium concentration in their substrate are 9.49 mg/kg,6.37 mg/kg and 7.69 mg/kg,respectively.Comparing with the GB 2762-2005(maximum levels of contaminants in foods) and the GB 15618-1995(environmental quality standard of soil),the results showed that the soil of artisanal zinc smelting areas had been seriously contaminated by Cd.There are more than seven times the average of Cd concentration in the soil as compared with GB 15618-1995.Different bryophyte species has different capacity to absorb Cd from the natural environment,and the heavy metal content in bryophytes has positive correlations with the substrate.Therefore,bryophytes can be a good monitor for estimating cadmium pollution in artisanal zinc smelting areas.