Comprehensive assessment of the condition of Crimean pine (Pinus nigra subsp. pallasiana (Lamb.) Holmboe) stands on eroded lands in the Right-Bank Forest-Steppe of Ukraine

The relevance of this study connected with the need to assess the condition of planted stands of Crimean pine (Pinus nigra subsp. pallasiana (Lamb.) Holmboe) established on eroded ravine and gully lands. The objective of this study was comprehensively assess the condition of Crimean pine (Pinus nigra subsp. pallasiana (Lamb.) Holmboe) stands established on eroded ravine and gully lands in the Right-Bank Forest-Steppe of Ukraine by: analysing their silvicultural and mensurational characteristics; evaluating the physical and agrochemical properties of the soils; determining the relationships between stand development and soil-improving processes; and assessing stand condition using an integrated condition index based on a wide range of indicators. The methodology for studying the condition of pine stands was to collect the various indicators data: silvicultural and mensurational data, as well as the physical and agrochemical properties of the soil. The study included the following forestry and inventory indicators: age (years), average height (m), average diameter (cm), density (1.0), and standing volume (m³·ha^-1); from soil physical properties: humus horizon depth (cm), active root surface area (cm²), water permeability (mm·min^-1), and soil hardness (kg·cm^-2); from agrochemical properties – humus content (%), available phosphorus, potassium, and hydrolyzable nitrogen (mg per 100 g of soil). When using indicators with different absolute values, it was planned to convert them to relative values by calculating them based on identical control indicators. Eleven plots of pine stands aged 25 to 55 years with forest management characteristics that were as similar as possible or identical were selected. The studied Crimean pine stands grow in II and III stand site indexes under dry (C₁) and fresh mixed broadleaf forests (C₂) conditions, with timber productivity ranging from 72 to 334 m³·ha^-1. They fulfill their designated erosion control function by halting the progression of erosion processes through the regulation of soil permeability and hardness, between which an inversely proportional relationship has been observed. They contribute to improving the properties of eroded soils by increasing the integral soil improvement index from 120% to 180%. Crimean pine stands have high overall health indices, which do not exceed 20%; at the same time, they differ from one another, exhibiting certain variations. The method of comprehensive assessment of stand health, based on the overall index, provides an unquestionable opportunity to take into account a wide range of indicators that influence the characteristics of their growth and development.