Role of Silviculture in the Formation of Norway Spruce Forests along the Southern Edge of Their Range in the Central Russian Plain

Abstract

East European forests dominated by Norway spruce (Picea abies (L.) H. Karst.) in the broad-leaved–coniferous zone should be considered as secondary communities formed under the influence of centuries-long activities (logging, fires and planting) and extended outside their natural range. The study raises an issue—how stable is the current state of Norway spruce forests in the center of the Russian plain and what is the effect of silviculture on the forest cover of the large urban agglomeration—the Moscow Region? Current study is based on multidisciplinary research and consequently concerns the age dynamics of spruce plantation forests, the species and typological diversity of mature spruce forests and spatial pattern of spruce forests along the south edge of their range. The composition and structure of Norway spruce plantations have been studied for various age classes and compared with mature natural spruce forests and pine plantations on the basis of field data. Remote sensing data and modeling approach were applied to estimate the spatial structure of spruce forests. It is found that mature plantations (over 80 years) become similar to natural forests in terms of structure and composition. The relationship between the distribution of spruce formations and the climatic and geomorphological conditions are confirmed. The proportion of spruce and spruce–aspen/birch communities follows the pattern of zones—the transition from the coniferous and broad-leaved forest zone to the broad-leaved forest zone. Despite the significant anthropogenic impact and the high proportion of plantations in the composition of Norway spruce forests (about 60–80%), their floristic and typological diversities correspond to such properties of zonal broad-leaved–coniferous communities. Over-matured plantations can provide valuable habitats for the re-establishment of native typological diversity. This makes it possible to use silviculture stands as an accelerated alternative to the natural recovery of disturbed habitats.