сосна обыкновенная

Purpose. The study of changes in the main agrochemical parameters in the upper layers of the gray forest soils of the Left Bank Forest-Steppe of Ukraine that were removed from agricultural processing and forested with pine, in different years. Methods. Theoretical methods included the collection and description of facts, their analysis. Empirical methods involved conducting field research on test plots of the state-owned enterprise “Chu-guevo-Babchansky LG” and farm near woodlands. Laboratory and analytical studies were performed using standardized measurement methods. The generalization of the experimental data was performed using applica-tion software packages. Results. Studies were carried out on soils under natural forest plantations, soils in inten-sive agricultural processing and unproductive soils that are derived from agricultural use. In all the studied soils, the main agrochemical parameters were compared among themselves: mobile forms of nitrogen, pH, humus content, content of common forms of nitrogen, phosphorus and potassium. Statistical dependences between agrochemical parameters in the studied variants were established. Conclusions. The results obtained indicate the revitalization and development of humification and accumulation of nutrients in old arable gray forest soils with an increase in the duration of exposure to pine forest. The age stages of the forest determine the specifics of the environmental factors that influence the soil-forming processes. In the soil of a young pine-tree (12 years), there are more cases of an increase in the coefficients of spatial variation. This indicates that the formation of young ecosystems are characterized by low resistance, in these biocenoses the dynamic equilibrium is not reached, which is characteristic of more mature pine forests.

Purpose of this research was to detect influence of climatic change on pine radial increment in stand in the Left-bank Forest-steppe of Ukraine as example 100-years-old stand at State Enterprise 'Kharkiv forest scientific research station’. Methods. Dendrochronological. Method of correlation function and multiple regressions (re-sponse function) were used to analyze the influence of climatic factors on tree radial increment. For this purpose computer program RESPO was used. Results. Tree ring series were built and were used for correlation analysis between climatic factors and pine radial increment for two periods: 1960-1988 and 1988-2016.Years of mini-mum (1933, 1942, 1956, 1972, 1976, 1976, 1987, 1992, 2002, 2006 та 2012) and maximum (1933, 1942, 1956, 1972, 1975, 1976, 1979, 1979, 1979, 1987, 1992, 2002 та 2012) of radial increment were detected. Depressions of pine radial increment were as a result of negative weather conditions: low and high winter and early-spring temperature, droughts during vegetation period. Maximums of radial increments were depended on favorable weather conditions for pine radial growth. Correlation and Response analysis for two periods showed that increase of temperature and precipitation, excluding winter precipitation, changed response of forest ecosystems to climatic change: if in first period (1960-1988) radial increment limited by April temperature and together July temperature positively influenced on radial growth, in second period (1988-2016) June temperature negatively infuenced on radial increment. Slight increase precipitation during vegetation period could not soften impact if high temperature during vegetatation period on tree radial increment. Conclusions. At comparison 1960-1988 and 1988-2016 it was detected that during first period positive influence of summer temperature on radial growth was distinctive and for second period one started to limit increment (negative influence) were detected. Slight increase of precipitation for vegetation period in second period significantly didn’t influence on pine radial growth. In second period increase of winter temperature and number of thaws negatively influenced on soil moisture, decreased of tree ring widths.