6Singh O V, Labana S, Pandey G, et al. Phytoremediation: an overview of metallic ion decontamination from soil [ J ]. Ap- plied Microbiology and Biotechnology, 2003,61 ( 5 - 6 ) : 405 - 412.
7Meets E, Vandecasteele B, Ruttens A, et al. Potential of five willow species (Salix spp. ) for phytoextraction of heavy metals [ J ]. Environmental and Experimental Botany, 2007,60 ( 1 ) :57 - 68.
8Jensen J K, Holm P E, Nejrup J, et al. The potential of wil- low for remediation of heavy metal polluted calcareous ur- ban soils [ J ]. Environmental Pollution, 2009,157 ( 3 ) : 931 - 937.
9Zhivotovsky O P, Kuzovkina YA, Schulthess C P, et al. Lead Uptake and Translocation by Willows in Pot and Field Experiments [ J ]. International Journal of Phytoremedi- ation,2011,13 (8) :731 - 749.
10Chen G C, Liu Z K, Zhang J F, et al. Phytoaccumulation of copper in willow seedlings under different hydrological regimes[J]. Ecological Engineering,2012,44:285 - 289.