Ecologists from the Institute of Plant Physiology RAS found out how emissions of the largest cement plant in Russia, built in the Bryansk region more than a century ago, affect the state of the soil and conifers. Their findings were presented in the journal Environmental Pollution.
“The most pronounced effect of the long-term effect of the cement plant on conifers was manifested in the development of an acute shortage of manganese in the branches and needles, cones and seeds. This led to a decrease in seed yield, a decrease in their germination and a decrease in the regeneration potential of pine stands, ”says Vladimir Kuznetsov from the Institute of Plant Physiology, RAS in Moscow.
Modern cement was invented by the British engineer John Smeton in the mid-18th century, and since then its production technology and chemical composition have changed little. It is a mixture of gypsum, calcined limestone and clay. It turns into a hard, stone-like material when stirred in water and in contact with air.
As a rule, cement is produced by burning its components in special clinker kilns. This process leads to the release of large quantities of carbon dioxide, heavy metal ions, other gases and dust into the atmosphere. In most cases, the mass of these emissions is almost equal to the weight of the cement produced, and environmentalists have been trying for a long time to assess how such pollution affects the environment.
According to the press service of the Russian Science Foundation, Kuznetsov and his colleagues found out how such plants affect nature in the long run, studying how emissions from the Maltsovsky Portland cement plant, built in 1899 in the city of Fokino, by the famous family of Russian industrialists, affect life of the nearby Bryansk forests.
They were interested in how this enterprise influenced the formation of cones of local pines and their seeds, how their water balance and metabolism changed in similar conditions and in cleaner areas of the forest.
To assess the level of pollution and how it has changed over time, environmentalists collected soil samples and divided them into layers formed in the past decades and relatively recently. By comparing their contents, Kuznetsov and his team were able to figure out how much heavy metals and other potentially dangerous substances had thrown the plant in Fokino in the past and how they affected the trees.
These differences were quite serious – the soils contained about 30 times more calcium and were more acidic at a distance of 1-2 kilometers from the cement factory. In addition, they contained about 7-40 times more lead, copper and other heavy and potentially toxic metals than in the clean corners of the Bryansk wilds.
On the other hand, the amount of “edible” compounds of some other trace elements, such as manganese, iron and zinc, has noticeably decreased. This extremely negatively affected the growth rate of pines and reduced the rate of formation of cones. For example, in the most polluted areas of the forest cones were on average 20% smaller in size than in other parts of it, and the number of viable seeds in them decreased by a third.
“We assume that in the long term, the natural acidity of forest soils will be restored, but at the same time, heavy metals will become toxic and more accessible to plants. In this regard, in contaminated areas it is advisable to monitor the state of forests and the level of metals in soils, ”Kuznetsov concludes.
RIA Novosti https://ria.ru/science/20181102/1532004808.html
