Comparative analysis of heavy metals accumulation in the needle of introduced species in the green zone of nur-sultan

Comparative analysis of heavy metal accumulation in the needles of introduced species in the green zone of Nur-Sultan has been carried out. 10-year-old forest plantations created from introduced conifers of the genus Spruce (Picea), Fir (Abies) and Larch (Larix) have been investigated in the green zone of Nur-Sultan. Siberian spruce (Picea obovata Ledeb.) has the greatest ability to absorb heavy metals, then (in decreasing order): black spruce (Picea mariana Mill.), Engelmann spruce (Picea engelmannii Parry ex Engelm.), Siberian fir (Abies sibirica Ledeb.), Siberian larch (Larix sibirica Ledeb.), Colorado spruce (Picea pungens Engelm.). The needles of introduced species were found to exceed the MPCs for lead (Pb), cobalt (Co), and manganese (Mn). High concentration of manganese led to a decrease in the concentration of active iron (Fe), the manganese-iron ratio in trees of the Spruce genus was 1.6-2.9: 1 in all the studied conifers. The content of this element in Siberian larch was the highest (34.9 mg/kg) one, but iron was also present in a fairly large amount (19.7 mg/kg), so the manganese-iron ratio was 1.8:1. Gas resistance and a tendency to accumulate heavy metals in needles, decorativeness and high preservation have been shown by spruce Siberian, which can be recommended for planting in the green zone. Black spruce and Engelman spruce are also resistant to unfavorable environmental factors and decorative. The accumulation capacity and safety of Siberian larch, as well as Siberian fir, is very low, so these species should not be recommended for growing in the green zone of Nur-Sultan