| The Water-Level-Fluctuating-zone is also known as the water level change zone,which is generally considered as the junction of land and river,with the function of connecting the land and water environment.Affected by the fluctuation of water bodies such as rivers,lakes and reservoirs,the water area connected with the land on the water level zone will be periodically submerged and exposed by the water body.After a long-term natural succession,the water level change zone has a large number of adaptive plants that can adapt to extreme environment The vegetation in the fallow zone has high productivity and biomass,and has strong migration and transformation ability to mercury and methylmercury in the reservoir environment.In this study,the dominant plants of Baihua reservoir in Guizhou Plateau with relatively heavy mercury pollution were selected for simulation experiment.By adding Hg Cl2 of different concentrations to the growth environment of three kinds of plants and the ecological environment of simulated water flooded and semi water flooded land,the mercury and methylmercury contents in different vegetative organs?roots,stems and leaves?of three kinds of plants were measured,and the living plants in the water flooded land were discussed The migration and transformation of mercury and methylmercury in the long-term process can provide an important reference for understanding the migration and transformation of mercury and methylmercury in the plant of the ebb belt under the special ecological system and special environmental conditions.The results are as follows:?1?Three kinds of plants in the ebb zone,Phalaris arundinacea L.?Acorus calamus L.and Cynodon dactylon?L.?Pers can grow and survive in six concentrations.Three kinds of plants do not show intolerance or stress in the Hg Cl2 soil with the maximum concentration of 50 mg/kg,and all of them can grow and survive in the soil with higher mercury pollution.All of the three plants showed a certain enrichment ability to mercury and methylmercury,among them,the absorption and enrichment ability of Phalaris arundinacea L.and Acorus calamus L.to mercury and methylmercury was stronger.?2?The total mercury content in four months of Phalaris arundinacea L.was 5.1060-4788.7229 ng·g-1,the total mercury transfer coefficient TF value was 0.004-1.221,the methyl mercury content was 0.4630-260.3724 ng·g-1,the methyl mercury transfer coefficient TF value was 0.003-8.274,and the total mercury content in four months was 19.9750-8301.2183 The total mercury transfer coefficient?TF?ranged from 0.008 to 0.919,the methylmercury content ranged from 3.8370 to 558.8023 ng·g-1,and the methylmercury transfer coefficient?TF?ranged from 0.027 to 0.597.?3?The total mercury content of Acorus calamus L ranged from 5.1548 to 2132.8242 ng·g-1,the total mercury transfer coefficient TF value ranged from 0.015 to 1.841,the methyl mercury content ranged from 1.1776 to 200.5239 ng·g-1,the methyl mercury transfer coefficient TF value ranged from 0.003 to 4.800,and the total mercury content of Acorus calamus calamus ranged from 4.0914 to 3245.5342 in four months under the semi submerged environment The total mercury transfer coefficient?TF?ranged from 0.027 to 0.713,the methylmercury content ranged from 0.7036 to 356.1306 ng·g-1,and the methylmercury transfer coefficient?TF?ranged from 0.044 to 1.419.?4?The total mercury content of Cynodon dactylon?L.?Pers ranged from 28.7896 to 3709.5418 ng·g-1,the total mercury transfer coefficient?TF?ranged from 0.040 to 0.713,the methyl mercury content ranged from 1.7188 to 115.0069 ng·g-1,the methyl mercury transfer coefficient?TF?ranged from 0.108 to 0.546 in four months without flooding,and the total mercury content of bermudagrass ranged from 12.4886 to 10988.6885 in four months under semi flooding The total mercury transfer coefficient?TF?ranged from 0.007 to 2.426,the methylmercury content ranged from 1.5189 to 977.6913 ng·g-1,and the methylmercury transfer coefficient?TF?ranged from 0.006 to 3.003.?5?The absorption capacity of different plant organs is different.The proportion of total mercury and methyl mercury in plant leaves and stems is not high.The absorption of mercury and methyl mercury in plant roots is easily enriched in plant roots.The enrichment of mercury and methyl mercury in plant roots is greatly affected by the content of soil mercury.The concentration of total mercury in soil is the key factor affecting the content of total mercury and methyl mercury in the whole plant. |
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