In 2015 through 2018, eleven test plots were studied in recreation areas planted with Pinus silvestries pine trees and Picea albea spruce trees. The plots were located in Saint Petersburg and Vyborg (Russia) and Narva-Jõesuu (Estonia). The main factor of decay of both pines and spruces were total toxic salt levels in soil and acidity of soil. Correlated with these factors are the levels of sodium, magnesium, calcium, chloride, bicarbonate, and sulfate ions. The conditions of spruces correlated most significantly with chloride ion levels. The coefficients of regression of the estimates of conditions of pines and spruces on the estimates of soil pollution are not different, in spite of the fact that the arrangements of roots are different in the two tree species. A possible cause of the lack of differences in the coefficients is that toxic salts diffuse into deep soil layers. Factors associated with the presence of humans in the respective recreation areas, as well as pests and climate do not influence the stands. However, upon the highest pollution and the associated attenuation of stands, the activities of pests are highest. Regressions found based on the results obtained during the study may be used for forecasting the conditions of pine and spruce stands at lethal and maximum permissible levels of soil pollution. Differences in the threshold levels of pollution and in the standard errors of regression coefficients between study sites are not high. This makes it possible to use the mean values of these parameters as reference values of maximum permissible and lethal levels of soil pollution and for monitoring and forecasting the conditions of coniferous stands.
Алексеев, А. С., Ходачек, О. А., & Селиховкин, А. В. (2019). Анализ факторов ослабления хвойных древостоев в рекреационных насаждениях. БИОСФЕРА, 11(1), 48-61. https://doi.org/10.24855/biosfera.v11i1.475