Since the 1980s, comprehensive studies have been conducted on the pollution impact on forest ecosystems in the following types of pollution: Rivne VAT “Azot”, Cherkasy and Lysychansk-Rubizhne-Siverodonetsk industrial agglomerations. Balakliia VAT “Baltsem” Zmiiv Thermal Power Plant. The highest emission level was recorded in the 1980s, and it decreased since the first half of the 1990s due to the decline and halting in production. According to the study, in the case of emissions to air, the snow cover is polluted, and its chemical composition reflects the qualitative and quantitative changes in pollution.
Despite the dominance of acidic emissions, precipitation is alkalized by ammonia emissions. Strong alkalization also occurred in the zone of cement production. The pH value of the snow cover in the sanitary and protection zone reached 11.
The degree and nature of production-induced changes in soils depend on the pollution characteristics and soil properties. The main trends of changes in the soil-absorbing complex, inhibition of microbiological activity and, as a consequence, decrease in the content of humus and nutrients were revealed.
The main specificities were determined for different types of pollution. For example, in the zone around plants emitting acidic sulfur- and nitrogen-containing pollutants, the acid balance is disturbed due to the alkali metals leaching, absorption capacity decreasing, and base saturation reducing. These negative changes are most pronounced in Polissya and are less noticeable in Steppe.
The emission of nitrogen-containing contaminants does not compensate for the loss of nitrogen resulted from the decline of microbiological activity. It worsens the supply of nitrogen to plants as the part of its available forms decreases.
In the area around cement production, the soil is heavily alkalized due to the abnormal concentration of alkali metals. In the soil adsorption complex, the hydrogen ion is mostly replaced by calcium. The maximum amount of alkali metals accumulates in the upper soil horizon. In light loamy and sandy soils, alkalization goes much deeper. The level of soil alkalization increases during heatwaves.
Sedimentation of emissions from thermal power plants and cement production results in areas with anomalous concentration of heavy metals. However, while such areas have a local character in the Baltsem zone, they are taking on regional dimensions in the TPP zone.
The stock of alkali metals in the litter 40-60 times exceeds that in the tree waste, and it can reach hundreds of times for some heavy metals.
The intensity of the biological circulation in the “tree waste – litter” link is inhibited due to the pollution. At the same time, tree waste decreases, and litter weight increases. The slow biological circulation peculiar to pine forests falls to hindered one in case of heavy pollution.
According to the study, the massive pine needle fall caused by the accumulation of pollutants, especially in dry years, begins much faster than the natural one. At the same time, the lifespan of pine needles can decrease by one or two years.
Due to early defoliation in severely damaged pine stands, the loss in the assimilative surface reaches 25% for one-year-old needles and 40% for two-year-old needles. Another 20-50% is lost due to inhibition of needle growth.
The shoots’ size and needle covering are reduced by 2–3 times due to contamination. The number of brachyblasts decreases by 1.6 times, and the internode length being an indicator of the phase of extra-bud growth of shoots by 1.4 times.
Phloem is less affected by air pollution than xylem. The width of the wood layer of annual shoots is decreased by 1.8–2.0 times and the bark width is reduced by 1.1–1.6 times in the contaminated area. The reason for this is a decrease in the number (1.3 times) and radial size (almost two times) of sieve tubes.
The phloem and xylem thickness is less in the lower part of the trunk than in the shoots. This difference increases by 4.75 times in the case of heavy pollution.
The effect of industry-related air pollution on the health condition of pine stands was assessed and peculiarities of horizontal and vertical forest structure changes were revealed as a result of the pollution. Specificities of radial growth dynamics under the influence of industry-related air pollution were found. Recommendations for increasing the resilience of forests damaged by industry-related air pollution have been developed.
In conditions of industry-related air pollution, the radial growth of pine stands is driven by the influence of a set of negative factors.
