Phytoremediation of technogenic landscapes using plants of the genus Salix L.

The phytoremediation potential of species of the genus Salix L. (Willow) was studied during the remediation of the industrial landfill of the OJSC “Karelsky Okatysh”. A plantation was created at this landfill in 2014. 7 species of the genus Salix were used for this purpose. The technogenic soil of the landscape was contaminated with iron up to 56 g/kg and was poor in basic macro- and microelements. Biomorphological (growth, organ weight) and physiological indicators (photosynthetic pigments content, leaf cell wall composition), as well as metal accumulation (biological absorption coefficient of metals (BAC)), were analyzed for willow plants during 4 years. We found that S. schwerinii (93%), S. phylicifolia (80%), and S. viminalis (70%) had the maximum survival rate after planting. The photosynthetic pigments content and the special leaf index (SLA) of S. phylicifolia and S. shcwerinii leaves allowed us to evaluate the photosynthetic function of plants as optimal in conditions of soil iron contamination and a lack of macro-microelements. The average series of metal accumulation by a whole plant in species of the genus Salix is as follows: Zn (31.92) > Cd (11.83) > Mn (5.10) > Pb (4.64) > Cu (4.40) > Cr (1. 47) > Co (1.45) > Li (0.41) > Fe (0.17). Due to the high ion exchange capacity of the willow leaf tissues cell wall (1120–2050 µmol/g of dry cell wall weight), metals can µind in the plant µody. Phenolic and pectin suµstances dominate in the structure of the cell wall of willow leaves. Willows will continue to perform the function of afforestation of technogenic territory and create conditions for the development of a productive forest phytocenosis.