Investigation of Heavy Metals Hyperaccumulators in the Process of Natural Recovery on a Steel Plant Site

LUO Lian; SU Honglin; CHEN Xideng; LIANG Huabo; CUI Yaode; LIN Shishi; TANG Li

doi:10.3969/j.issn.1003-6504.2017.09.0120

Abstract：Vegetation in the process of natural recovery on the 3-year site after the relocation of Guangzhou Steel Plant was investigated,plant species composition,life form composition,important value of various plants,diversity index and evenness index of the plant community were analyzed,and heavy metal tolerance of species was compared.Results showed that in 6 plots,there are 26 species belonging to 14 families,of which the number of Compositae and Gramineae plants are the most,but Leguminosae plants are not found.About the plant life form,21 species,accounting for 80.77％,are annual or biennial and perennial grasses,rarely shrubs and trees,indicating the vegetation is in the primary stage of the secondary succession.Important value of these species differ little,with the maximum 32.10 of Pteris vittata,followed by Solanum americanum,Boehmeria nivea and Sphagneticola calendulacea,whose important value are greater than 20;important value of the rest 14 species are less than 10.Dominant species in the community are not obvious,which indicates that the composition of the community is more complex.The average plant coverage is 27.16％,the species diversity index is 0.93 and evenness index is 0.89.The plant number is large but the plant height is short,leading to higher species diversity index and evenness index,but lower coverage.It indicates that plant seed germination is small influenced by heavy metal stress,but plant growth is larger influenced by heavy metal stress.There are 3 heavy metals hyperaccumulators,which are Pteris vittata,Solanum americanum and Sphagneticola calendulacea.Other 8 species have certain tolerance to heavy metals.For ecological restoration of steel plant site,plants with remediation function can be used to construct plant landscape to tree,shrub and grass combination of eco-economic type community.