Modern Dynamics of Old Growth Spruce Forests in the Centre of the Russian Plain

Forests dominated by Norway spruce (Picea abies (L.) H. Karst.) within the mixed forest zone are often considered communities formed under the influence of centuries of human activity (logging, plowing, fires, and tree planting in the modern era of forest management). This study addresses the question of how stable is the current state of old-growth spruce forests in the central Russian Plain. This question was addressed by comparing the composition and structure of the tree and shrub layers of spruce forests in the Smolensk-Moscow Upland (Moscow Region) as part of a long-term forest dynamics research program. The study is based on repeated geobotanical descriptions at intervals of approximately four decades (1987—2024) at 56 sites in protected forest areas of the region. The main trends in the successional dynamics of spruce forests were tracked, taking into account the composition of edificators in the tree and shrub layers of the communities and the environmental conditions of the habitats. It was established that in the study area, after the collapse of old-growth spruce forests, two opposing types of secondary successions were formed: 1) with regenerating spruce and 2) with the active shrub development (hazel and rowan) and the undergrowth of broadleaved species. The study highlights the value of long-term field observations and a detailed analysis of the composition of cenopopulations of the main forest-forming species. The results can contribute to the development of plans for sustainable forest management and the conservation of biodiversity of natural communities under different forest management scenarios.