2026 Ecosystem Transformation 9 (4), 93-120

Landscape features of the spatial distribution of mixed pine and spruce stands in the Leningrad region

Mixed stands with the dominance of pine and spruce occupy up to a quarter of the area of the forest fund in the conditions of the North-West of Russia. Modern forest management and the current regulatory framework are aimed at the formation and cultivation of pure softwood stands, but in certain climatic, soil and hydrological conditions mixed softwood stands grow more successfully and productively. Modern silvicultural activities and the current regulatory framework are aimed at the formation and cultivation of pure coniferous stands; however, under certain climatic, soil, and hydrological conditions, mixed coniferous stands grow more successfully and productively. This study examines the spatial distribution patterns of mixed pine and spruce stands in the Valdai-Tikhvin and Luga-Volkhov landscape districts of the Leningrad region. To identify the predominant types of mixed stands in each landscape, the Shannon, Simpson, and Pielou biodiversity indices were calculated. To assess the influence of landscape conditions on the distribution of mixed stands, the Spearman rank correlation coefficient was calculated. It has been established that different types of mixed stands are formed depending on landscape conditions, with soil-hydrological conditions having a decisive influence on their distribution. In the Valdai-Tikhvin landscape district, spruce-deciduous and spruce-pine stands predominate among mixed stands by area. In the Luga-Volkhov landscape district, spruce-deciduous stands occupy the largest area among mixed stands, which is associated with significant anthropogenic impact on this landscape district. Under predictive modeling through the felling rotation cycle (100 years), spruce-deciduous stands will predominate in the studied territories.