ASSESSMENT OF THE ECOLOGICAL CONSEQUENCES OF THE INTRODUCTION OF EXOTIC REPRESENTATIVES OF THE FAMILY PINACEAE IN THE SOUTH OF SAKHALIN: IMPACT ON NATIVE ECOSYSTEMS, SOIL CHARACTERISTICS, AND BIODIVERSITY

Nikolaev Dimitriy Vladimirovich

The study provides a comprehensive assessment of the ecological consequences of introducing exotic species of the family Pinaceae under monsoon climate conditions of southern Sakhalin Island. An analysis was carried out on the effects of 12 introduced coniferous species on native ecosystems, soil characteristics, and biodiversity during 2021–2024. The ecological impact assessment included analysis of competition with local species, changes in physicochemical properties of soils, transformation of plant community structure, and influence on biotic components. Indicators of litter allelopathic activity, dynamics of mycorrhizal associations, changes in herb–shrub layer species composition, and transformation of soil microbiological activity were investigated. The greatest negative effects on native vegetation were demonstrated by North American species Pseudotsuga menziesii and Pinus ponderosa, with competitive pressure indices of 7.2–7.8 points and understory species diversity decrease by 34–42%. Moderate impacts were observed for European species Picea abies and Pinus sylvestris, with competitive pressure indices of 5.1–5.6 points and species richness reduction by 18–24%. Correlations were established between growth intensity of introduced species and scale of ecosystem transformation.

Keywords:conifer introduction, Pinaceae, ecological consequences, competition, biodiversity, soil characteristics, allelopathy, Sakhalin